WO1997020271A1

WO1997020271A1 - Wide bandwidth network technology

Info

Publication number: WO1997020271A1
Application number: PCT/US1996/018196
Authority: WO
Inventors: Roger E. Billings; Michael O. Schmidt
Original assignee: Wideband Corporation
Priority date: 1995-11-13
Filing date: 1996-11-12
Publication date: 1997-06-05
Also published as: EP0861469A1; CA2237406A1; AU7730396A

Abstract

A computer network (200) includes a network hub (202) which connects a plurality of computers (12) together. Data packets generated by the computers (12) are sequentially merged into a stream of data packets which is then broadcast to all of the computers (12) in the network (200). The network hub (202) includes a plurality of ports (206), each of which is connected to a respective one of the computers (12), receiving data packets generated by the computer (12). The network hub (202) also includes a plurality of storage devices (210) respectively connected to the ports (206). Each of the storage devices (210) receives and temporarily stores the data packets received by the port (206). A merging processor (212) is connected to each of the storage devices (210) and sequentially merges data packets temporarily stored by the storage devices (210) into a stream of data packets. The stream of data packets is then broadcast to each of the computers (12) in the network (200). The network hub (202) may communicate with each of the computers (12) to indicate the capacity status of the storage devices (210).

Description

WIDE BANDWIDTH NETWORK TECHNOLOGY

BACKGROUND OF THE INVENTION

Field of the Invention

The present invention relates to computer networks and, more particularly, to computer networks in which data is communicated among a plurality of computers.

Description of Related Art

Computer networking involves moving data from one point to another. Computer networking or "interoperation" usually begins with computers in the same office or the same building connected in a local network. The term "local area network" or LAN describes a group of computers typically connected by no more than 1,000 feet of cable which interoperate and allow people to share resources.

In the late 1970s and early 1980s, important work was done on LANs for a large number of computers. An important set of standards and protocols called "Ethernet" was conceived and developed to the point of becoming a commercial product. At about the same time, another set of standards and protocols known as "ARCNET" was developed. Soon thereafter, a third major networking technology known as "Token Ring" was developed.

With the rapid increase of interest in networks, particularly local area networks, client/server computing is quickly becoming the backbone of data processing systems. As local area networks expand and as data processing tasks become more complex, networks become more congested, resulting in poor performance and requiring more complicated customer installations.

Many of today's applications require networks with high bandwidth capabilities.

Databases are becoming larger and more sophisticated and are being accessed by greater numbers of users. Further, many industries have been migrating toward applications involving high-resolution color graphics, which applications require high bandwidth to handle the large amount of data involved with this type of graphics.

In many application environments, it is often desirable to store executable files in central data servers or file servers, to which computer workstations in the network are connected, rather than on the local disk drives of workstations. This is because the application programs must be constantly maintained and updated to ensure compatibility with new peripherals and to take advantage of the latest revisions. This approach is especially advantageous in large organizations where the technical labor requirement for updating application programs at every workstation is impractical.

However, when a substantial number of users (i.e., computers) simultaneously load program files over the network, bandwidth quickly becomes a serious problem. Even networks with fewer than 100 workstations can become unusably sluggish in performance when the users are actively loading and executing programs from, for example, the Windows™ environment, over the network.

To alleviate these problems, the common wisdom has been to install more file servers and to divide the network into smaller local area networks connected together by routers or bridges. W ile this approach has greatly improved performance for many organizations, it is costly and creates delays and complications when it is necessary for users to share information over a wide area of the network.

The computer industry is responding to these problems with a diversity of new and innovative products. Ethernet adapters with data rates of up to 100 megabits per second (Mbps) are now commercially available and are quickly becoming affordable. Another approach, known as "switching hub technology," dedicates a portion of the LAN to a single or small group of users. Many Token Ring LANs have also risen to the challenge to find ways to increase their performance and are operating at 16 Mbps.

Most networking managers are looking forward to the introduction of Asynchronous Transfer Mode (ATM) protocol as the solution to their networking bandwidth problems. Although most analysts see ATM as the wave of the future, its emergence has been slower than predicted, because ATM doesn't neatly fit the layered models common to existing networks and the ATM specification itself does not encompass such things as speed and protocols. ATM is a sophisticated switch networking system that hosts an active application at each end. Although it breaks data into 53-Byte "Cells," ATM is not a packet switched or router network architecture. In fact, for every stream of data sent, ATM creates a virtual circuit among two or more points. Many on-line services, newspapers, and cable television providers believe ATM, with its roots in a telecommunications effort to unify voice and data transmissions, is the pipe they need to deliver large amounts of information to a desktop or set top box. But for that to happen, users will need faster PCs, ATM aware applications, and lower prices.

Existing networks have achieved a degree of interoperability through a foundation in the seven-layer Open Systems Interconnection (OSI) model. ATM, on the other hand, with its dedicated point-to-point connections, is a clear deviation from current technologies. To implement the ATM approach, application software needs to be modified to become ATM aware. This is necessary since the topology differences between ATM and today's networking schemes will require logical decisions which, in some cases, cannot be adequately provided through customized physical layer interfaces and drivers.

Network Interface Cards

Network interface cards, sometimes called LAN adapters, function as an interface between the computer and the network cabling, linking the computer to the network cable system. The card controls the flow of data between the computer's internal data bus and the serial stream of data on the network cable. Some computers are provided with a network interface card on the motherboard of the computer, but the cards are usually added to the computer's expansion bus. Network interface cards also change the form of the computer generated data from a wide parallel stream, e.g., 8 bits at a time, to a narrow stream moving 1 bit at a time in and out of the network port. Conventional network interface cards buffer data because the computer is typically much faster than the network. Many network interface cards have a processor specially designed for on-board processing power. These processors are augmented by 8K to 64K of RAM and by specialized transceivers that handle the electrical interface with the cable.

Network interface cards generate the electrical signals that travel over the network cable. Each network interface card follows specific rules controlling access to the cable. Network interface cards for Ethernet and Token Ring both use the same basic system of electrical signaling of the cable. A technique called Manchester encoding provides a way to transmit Os and ls using direct current voltage pulses that range from - 15 to + 15 volts. The network interface cards translate each eight changes in the voltage level as a character in the ASCII data alphabet.

The Ethernet Protocol

In the Ethernet approach to networking, each data packet issued by each computer in the network is received by all the other computers in the network. A computer monitors the network to determine when the network is idle, at which time the computer may issue a packet. If the network is busy, the computer must wait. If two or more computers determine that the network is idle and respectively issue packets at the same time, a collision occurs. In busy Ethernet networks, collisions occur frequently. In an Ethernet network, the interface cards share the common cable by listening before they transmit and transmitting only during a break in the traffic when the channel is quiet. This technique is called carrier-sense multiple access with collision detection (CSMA/CD). With collision detection, if two stations begin to transmit at the same time, they detect the collision, stop, and retry after a sufficient time interval.

The Token Ring Protocol

Collisions are eliminated by the Token Ring approach. In a Token Ring network, packets travel from computer to computer in a closed-loop ring. A packet will travel in this manner until the packet reaches its address, at which time it is read and removed from the ring by the computer at that address.

Network interface cards for Token Rings use a complex media-access control scheme called "token passing." Whereas Ethernet cards contend for access to the cable, Token Ring cards must have permission to transmit into a cable system that forms a complete electrical loop or ring. Under this technique, the active cards negotiate, using their built-in serial number, to determine a master interface card. The master initiates a special message called a free token. When an interface card with data to send receives a free token, it changes the free token into a message and sends it to the next station up the ring for relay. After the addressed interface card receives the message and the message returns to the originating interface card, that card initiates a new free token and the process begins again. As a drawback, a computer must wait for the marker before issuing a packet. Further, if a packet is addressed incorrectly or is otherwise undeliverable, the packet will endlessly circulate in the token ring. Therefore, special means must be provided to keep the ring clear.

The ARCNET Protocol

ARCNET network interface cards use a media-access control scheme. A designated "master card " maintains a table of all active network interface cards and polls each network interface card in turn, giving permission to transmit.

More specifically, ARCNET uses a star cabling pattern with passive and active hubs that can extend the cabling farther than Ethernet or Token Ring configurations. Networked devices share the cabling using an orderly polling scheme. The installer sets switches on each network interface card, which gives the card a specific number. The lowest numbered active card becomes a master controller. It sends a message to each adapter in sequence, giving it permission to transmit any data it holds. The standard ARCNET signaling speed of 2.5 Mbps limits the maximum throughput, although faster speeds have been recently developed.

The Asynchronous Transfer Mode Protocol

An ATM network is configured much like a telephone network. An issued packet travels from the issuing computer to the receiving computer on a communication line that other computers in the network are not currently sharing. Application software often needs to be modified to be compatible with an ATM network.

SUMMARY OF THE INVENTION

It is an object of the present invention to provide a network which mitigates and/or obviates the aforementioned drawbacks of conventional networking protocols.

It is another object of the invention to provide a network in which data is communicated in a highly efficient manner.

It is a further object of the invention to provide a network which operates much faster than existing networks. It is still another object of the present invention to provide a network which has a large bandwidth.

It is still a further object of the present invention to provide a network in which data is sequentially gathered on a reception channel and broadcast to the computers on a delivery channel. These objects as well as other objects, features, and benefits of the present invention are achieved by providing a computer network in which data packets generated by the computers in the network are merged into a stream of data packets by a network hub, which stream of data packets are then broadcast to each of the computers in the network.

According to one aspect of the present invention, a computer network includes a plurality of computers each having an interface, a plurality of data channels each connected to a data output of the interface of one of the computers, a broadcast channel connected to a broadcast input of the interface of each of the computers, and a network hub connected to each of the data channels and the broadcast channel. Each of the computers has a unique address and is capable of generating addressed data packets intended for delivery to another computer on the network. The network hub includes a plurality of ports each of which is connected to a respective one of the data channels for receiving addressed data packets generated by one of the computers, and a broadcast output connected to the broadcast channel. The network hub sequentially merges addressed data packets received at each of the ports into a stream of data packets. The stream of data packets are then broadcast to each of the computers in the network via the broadcast channel. To merge the addressed data packets into the stream of data packets, the network hub includes a plurality of storage devices and a merging processor. Each of the storage devices is connected to a respective one of the ports, and receives and temporarily stores the addressed data packets generated by the computer connected to the respective port. The processor is connected to each of the storage devices and sequentially merges addressed data packets temporarily stored by each of the storage devices into the stream of data packets. An internal bus is connected to each of the storage devices and to the broadcast output for delivering the stream of data packets to the broadcast output.

One of the advantages of the present invention is that a plurality of network hubs may be cascaded together. According to this aspect of the invention, the computer network includes a plurality of network hubs, each of which includes an expansion port. The expansion port is connected to the internal bus so that the expansion port receives the same stream of data packets that are delivered to the broadcast output of the hub. To serially connect the network hubs, the expansion port of one of the network hubs is connected to one of the ports of another network hub. Therefore, the stream of data packets from one network hub may be merged with the data packets received at the ports of another network hub, thereby forming a combined stream of data packets which is broadcast to the computers of the network.

According to another aspect of the present invention, the network hub may communicate with the interface of each of the computers to indicate whether the computer may transmit data packets to the network hub for merging. Specifically, when one of the storage devices of the network hub is filled or nearly filled to capacity with temporarily stored data packets, the network hub may send a status signal to the interface corresponding thereto, indicating that the storage device is near capacity. Accordingly, each of the interfaces includes a local storage device for temporarily storing addressed data packets generated by the computer upon receiving the status signal from the network hub, until the merging processor has emptied the storage device.

Other aspects, features, and advantages of the present invention will become apparent to those skilled in the art from a reading of the following detailed description with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a block diagram of an exemplary embodiment of a computer network implemented according to networking principles of the present invention;

FIG. 2 is a block diagram of a computer network illustrating networking principles of the present invention, particularly illustrating a chain of stations connected by a sequential reception channel and a separate delivery channel;

FIG. 3 is a block diagram of an exemplary embodiment of a network hub configured in accordance with networking principles of the present invention;

FIG. 4 is a block diagram of an exemplary embodiment of a network interface card configured in accordance with networking principles of the present invention;

FIG. 5A is a block diagram of an exemplary method of merging data packets implemented in accordance with the networking principles of the invention;

FIG. 5B is a block diagram of another exemplary method of merging data packets implemented in accordance with the networking principles of the invention; FIG. 6 is a block diagram of an exemplary embodiment of a network having mirrored servers implemented in accordance with networking principles of the present invention;

FIG. 7 is a block diagram of an exemplary embodiment of a network hub for use in a mirrored-server network configured in accordance with the invention;

FIG. 8 is a block diagram of an exemplary embodiment of a wide area network implemented in accordance with networking principles of the present invention;

FIG. 9 is a schematic view of an exemplary embodiment of a computer network implement in accordance with the present invention, particularly illustrating a file-server network configuration;

FIG. 10 is a schematic view of an exemplary embodiment of a network interface card implemented in accordance with the invention;

FIG. 11 is a schematic view of an exemplary embodiment of a computer network implemented in accordance with the invention, particularly showing a dual file-server network configuration;

FIG. 12 is a schematic view of an exemplary embodiment of a network hub implemented in accordance with the present invention;

FIG. 13 is a schematic view of an exemplary embodiment of a computer network implemented in accordance with the invention, particularly showing a wide area network configuration; FIG. 14 is a schematic view of an exemplary embodiment of a computer network implemented in accordance with the present invention, particularly illustrating a wide area network configuration with access to the Internet;

FIG. 15 is a schematic view of an exemplary embodiment of a computer network implemented in accordance with the present invention, particularly showing a wide area network configuration with access to a mail server;

FIG. 16 is a schematic view of an exemplary embodiment of a computer network implemented in accordance with the present invention, particularly showing a mirror-server configuration; FIG. 17 is a schematic view of an exemplary embodiment of a computer network implemented in accordance with the present invention, particularly illustrating a video-server network configuration;

FIG. 18 is a block diagram of another exemplary embodiment of a network hub illustrating packet-merging principles of the present invention; FIG. 19 is a block diagram of a network interface card for use with packet-merging network hubs;

FIG. 20 is a block diagram of a further exemplary embodiment of a network hub in accordance with the present invention; and

FIG. 21 is a block diagram of a plurality of packet-merging network hubs cascaded together according to the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Networking principles of the present invention are exemplified by the embodiments illustrated in the drawings. These principles focus on a two-channel approach to communicating data within a network environment. Exemplary embodiments of these networking principles may take different forms, many of which are illustrated in the drawings. However, the disclosure herein will detail specific preferred embodiments of this novel approach to networking and will not provide an exhaustive description of all embodiments within the scope of the networking principles set forth herein and in the appended claims.

The Network Referring to the drawings, particularly to FIG. 1, a network 10 implemented according to the principles of the present invention is shown. The network 10 utilizes two separate transmission channels to communicate data within the network 10. One of the transmission channels sequentially routes data issued from computers in the network 10 through the computers in the network. The other transmission channel broadcasts this routed data to all the computers in the network 10. As known in computer networking, data generated by computers is typically in the form of data packets. Each data packet includes not only the data generated by the computer but may also include addressing information, error detection information, and so on, so that each packet may be an addressed data packet.

More specifically, the network includes a plurality of computers 12, preferably being capable of generating data, in communication with each other via communication media. Each of the computers 12 is provided with a network interface card (NIC) 14. A network hub 16 interconnects the plurality of network interface cards 14, thereby interconnecting the computers 12 of the network 10. The network hub 16 also communicates via a broadcast output 18 thereof with a broadcast input 20 of each of the network interface cards 14.

The interface between the computer 12 and the network interface card 14 allows the computer 12 to generate data packets and to provide these generated data packets (i.e., local data packets) to the network interface card 14 for transmission to the network 10. The interface also allows the network interface card 14 to provide the computer 12 data packets received from the network or from a remote source (i.e., remote data packets).

As illustrated in FIG. 1, the computers 12 are connected in the form of a chain of computers beginning with a first computer (i.e., Computer 1) and ending with a last computer (i.e., Computer N) in the chain. In linking the computers 12 in this manner, data generated by Computer 1 is sent to the network hub 16 which in turn sends this Computer 1 data to Computer 2. In addition to sending the Computer 1 data back to the network hub 16, Computer 2 may also generate and send its own local data to the network hub 16. The network hub 16 then sends the Computer 1 and Computer 2 data to Computer 3. This sequential linking of the computers 12 continues through to the last computer in the chain, i.e., Computer N. The last computer, however, is not linked back to the first computer.

Computer N receives remote data packets from the network hub 16, which remote data packets are data packets generated by any one of or all of the computers preceding Computer N in the network (i.e. , Computer 1 through Computer N— 1). Computer N sends these remote data packets back to the hub 16, and may add local Computer N data packets to the chain of data packets. Therefore, data packets received by the network hub 16 from the last computer in the chain of computers, i.e., Computer N, are the data packets generated by any and all the computers 12 in the network 10, which may be called "network data packets." The network hub 16 then broadcasts these network data packets to all the network interface cards 14 in the network 10. Each of the network interface cards 14 then in turn provides these network data packets to the computer 12 connected thereto. Accordingly, all the computers 12 in the network 10 receive any data packet generated by any of the computers 12 in the network 10.

In view of the foregoing description, the networking principles of the present invention may be described as a network in which (1) data packets are sequentially gathered from the computers in the network on a reception or packet assembly medium and (2) the sequentially gathered data packets are delivered to all the computers in the network at the same time on a delivery or packet broadcast medium.

A block diagram illustrating this novel networking principle is shown in FIG. 2. The network 10 includes a plurality of nodes or stations 22 (each station 22 preferably including a computer and a network interface card) through which data packets issued by the stations 22 are sequentially chained and routed on a reception medium 24. The last station 22, i.e., Station N, provides the sequentially chained and routed data packets to a broadcast unit 26 which broadcasts these data packets from the last station to all the stations 22 on a delivery medium 28, shown in dashed line.

In order to describe the present invention as clearly as possible, generic terms for many of the devices and ideas common to networking technology are used. For example, in addition to the term "data" mentioned above, the term "computer" is used to described any electronic device capable of being connected within a network, including computer workstations, file servers, computer peripherals (which may not be capable of generating data to send over the network), and so on. The term "station" is used to describe a computer coupled with a network interface card. The term "communication media" encompasses all media forms used to communicate data, including, for example, coaxial cable, twisted-pair cable, fiber optical systems, infrared systems.

The Network Hub

A network hub implemented according to the principles of the present invention is shown in FIG. 3. The network hub 16 may function as a media access unit by configuring the communication media of the network 10 into a reception or packet assembly channel for sequentially routing data packets through the last computer in the network and a delivery or packet broadcast channel for broadcasting data packets routed through the last computer in the network to all the computers in the network.

In order to do this, the network hub 16 includes a plurality of input-and-output pairs 30. Each input-and-output pair 30 has an input 32 and an output 34 paired together. Each input-and- output pair 30 communicates with the network interface card of a station or computer of the network 10 via the delivery channel 24 as described above. The input 32 of each input-and- output pair 30 is connected to the output 34 of another input-and-output pair 30, shown by connection 36. Accordingly, data packets issued by a first station are received by the input 32 of a first input-and-output pair 30 and are then provided to the output 34 of a second input-and- output pair 30, which data packets are then sent to a second station. The input-and-output pair 30 communicating with the last station in the network, i.e., Station N, provides data packets received by the input 32 thereof to a broadcast amplifier 38. The broadcast amplifier 38 then provides these data packets to the broadcast output 18 to be broadcast to all the stations via the delivery channel 28.

The Network Interface Card A network interface card implemented according to the principles of the present invention is shown in FIG. 4. The network interface card 14 includes a remote input 40 and a remote output 42, each of which is connectable to the reception medium 24. The remote input 40 receives data packets from one of the input-and-output pairs 30 of the network hub 16 and provides these data packets to the remote output 42. The remote output 42 in turn provides the data packets to the next input-and-output pair 30 sequentially in the hub 16.

The network interface card 14 further includes a local input 44 which is connectable to the computer 12. The local input 44 is in communication with the remote output 42. The local input 44 receives data packets from the computer to which it is connected and provides these data packets to the remote ouφut 42 for transmission to the network hub 16 on the reception medium 24. The remote input and output 40 and 42 and the local input 44 are concerned with the gathering, merging, and routing of data packets in the network on the first transmission medium 24.

Regarding the handling of data packets on the delivery medium 28 of the network 10, the network interface card 14 further includes at least one but preferably two broadcast inputs 46 and a local output 48 in communication with the inputs 46.

The first broadcast input 46 is connectable to the delivery medium 28 of the network, receives the broadcast network data packets from the broadcast output 18 of the network hub 16, and provides the broadcast data packets to the local output 48. The local output 48 then provides the network data packets to the computer to which it is connected. Either the network interface card 14 or the computer to which it is coupled may determine which of the data packets of the broadcast data packets are addressed to the computer. According to the exemplary embodiment shown, the network interface card 14 may include a broadcast processor 49 connected between the broadcast inputs 46 and the local output 48. The broadcast processor 49 receives data packets from the broadcast inputs 46 and determines which of the data packets are addressed to the local computer. The broadcast processor 49 then transmits the data packets addressed to the local computer to the local output 48. In other words, the broadcast processor 49 monitors data packet traffic and captures only those data packets fulfilling the address requirement programmed by the local computer. The network interface card 14 may additionally include a memory device for storing address, as well as other, information.

If both broadcast inputs 46 are receiving data simultaneously, the broadcast processor 49 may toggle the connection between the broadcast inputs 46 and the local output 48. This may take place under software control from the local computer. Further, the computer may decide which of the broadcast inputs 46 to monitor and receive data from under different circumstances.

The Packet-Merging System In order to efficiently route data packets sequentially through the chain of network interface cards 14, each of the network interface cards 14 merges local data generated by the computer 12 with any remote data being received at the remote input 40. With continued reference to FIG. 4, the network interface card 14 in accordance with the present invention may also include a merging processor 50. The merging processor 50 is in communication with the local input 44, the remote input 40, and the remote output 42. The merging processor 50 alternatingly transmits to the remote output 42 local data packets received at the local input 44 and remote data packets received at the remote input 40. The merging processor 50, upon receiving local data from the local input 44, creates the local data packet to be sent out to the network via the reception medium 24. The preferred embodiment of the network interface card 14 also includes a local storage device 52 and a remote storage device 54. The local storage device 52 is connected between the local input 44 and the merging processor 50. The local storage device 52 receives data packets received at the local input 44 from the computer and provides these data packets to the merging processor 50. The remote storage device 54 is connected between the remote input 40 and the merging processor 50. The remote storage device 54 receives data packets received at the remote input 40 and provides these data packets to the merging processor 50. With additional reference to FIG. 5A, when local data packets are received at the local input 44 (block A) and loaded into the local storage device 52 (block B), the merging processor 50 detects the change in status of an "empty" flag in the local storage device 52. The local data packets are then immediately released to the merging processor 50 (block C) and transmitted to the network (block D) via the remote output 42. However, if the merging processor 50 is currently busy transmitting remote data packets (path E), the local data packets are then stored in the local storage device 52 (block F) until the merging processor 50 has transmitted the remote data packets to the network and is no longer "busy," at which time the local data packets are release by the local storage device 52 (block C) and transmitted to the network (block D).

If remote data packets are received at the remote input 40 (path G) while local packets are being released and transmitted to the network, then the release and transmission of local data packets is preferably temporarily suspended in order to transmit the remote packets through the network interface card 14 first, with any remaining local data packets transmitted thereafter. In other words, the transmission of remote data has priority over the transmission of local data. Upon receiving remote data packets, the remote packets are loaded into the remote storage device 54 (block H) and any yet unreleased (and untransmitted) local data packets are stored in the local storage device 52 (block I) so that the remote packets may be released to the processor (block J) and transmitted to the network (block K). When the received remote data packets have been transmitted, any remaining unreleased local packets may then be released and transmitted (path L and blocks C and D). This priority principle is alternatively illustrated in FIG. 5B. AS mentioned above, local data packets are received at the local input 44 (block M) and loaded into the local storage device 52 (block N). Similarly, remote data packets are received at the remote input 40 (block O) and loaded into the remote storage device 54 (block P). If local data packets are received and the merging processor 50 is busy with remote data packets, the local packets are then stored in the local storage device 52 (block Q). If the processor 50 is not busy with remote packets, then the local packets are released to the processor 50 and transmitted to the network until remote data packets are received (path S). When remote packets are received (block O), the processor 50 will transmit any released local packets to the network (block T), and any unreleased local packets are stored in the local storage device 52 (block U). Thereafter, the received remote data packets are released to the merging processor 50 and transmitted to the network (block W). After all the remote packets have been transmitted (path X), the release and transmittal of the local data packets may continue (block R). This entire process takes place at high speeds. If no local packets are being released and transmitted to the network and remote data packets are received at the remote input 40 (block O) and loaded into the remote storage device 54 (block P), then the merging processor 50 detects the change in status of an "empty" flag in the remote storage device 54. The remote data packets are then immediately released to the processor 50 (block V) and transmitted to the network (block W) via the remote output 42.

The Mirrored-Server Topology

The networking principles of the present invention may be implemented in many various network topologies. One such topology is a mirrored-server network which is a network having two file servers, one mirroring the other. Both file servers are configured to contain the same data, i.e., to "mirror" one another. Therefore, if one of the file servers crashes, the entire system will continue operating on the still- functioning file server.

Mirrored-server topologies are typically implemented in client/server networks. A client/ server network has a plurality of user workstations (or "clients") and a central file server (or "server") to which the workstations are connected. This is also called server-based networking. In contrast to peer-to-peer networks in which workstations address data packets to each other, the workstations in a client/ server network typically only address data packets to the file servers, with the file servers addressing data packets to the workstations.

With reference to FIG. 6, a network 56 with mirrored servers implemented in accordance with the present invention is shown. The network 56 includes a plurality of workstations 22 (each workstation 22 preferably including a computer and a network interface card) and a pair of file servers 58 connected together with communication media. Each of the workstations 22 generates data packets intended for delivery to the file servers 58, and each of the file servers 58 generates data packets intended for delivery to the workstations 22. The communication media through which the workstations 22 and the file servers 58 communicate includes a plurality of channels, e.g., Channels A to E, as described below. Each workstation 22 (except the last workstation in sequence, i.e., Workstation N) delivers data packets to the next workstation 22 in sequence on Channel A, and each workstation 22 (except the first workstation in sequence, i.e. , Workstation 1) receives data packets from the previous workstation 22 on Channel B. Channels A and B are thus configured in a packet assembly channel. Workstation N delivers these sequentially routed data packets to a broadcast unit (on Channel A). The broadcast unit 60 broadcasts data from the workstations 22 to both of the file servers 58 on Channel C which is a workstation broadcast channel. Therefore, both file servers 58 receive the same data packets.

The file servers 58 each generate data packets, the same data packets in a mirrored- server configuration, to be delivered to the workstations on separate broadcast channels. File Server 1 provides a first server broadcast unit 62 with addressed data packets which then broadcasts these File Server 1 data packets to the workstations 22 on Channel D which is a first server broadcast channel. Similarly, File Server 2 provides a second server broadcast unit 64 with addressed data packets which then broadcasts these File Server 2 data packets to the workstations 22 on Channel E which is a second server broadcast channel. Each of the workstations 22 then receives the File Server 1 and 2 data packets on a first and a second server broadcast input connected to Channels D and E, respectively. Accordingly, if one of the file servers 58 crashes, the network 56 will continue to function on the still-functioning file server 58. Each of the workstations 22 is then able to toggle between the first and second server broadcast inputs to determine which data packets to receive.

According to another exemplary embodiment of the present invention, rather than address data packets only for the file servers, the workstations 22 may address data packets for delivery to another workstation. In this case, each of the file servers 58 may merge data packets generated thereby with the workstation data packets received on Channel C, which is shown by the dashed line in each file server 58.

The Mirrored-Server Network Hub

With additional reference to FIG. 7, a network hub 66 implemented in accordance with the present invention is shown. As described with reference to the network hub 16 shown in FIG. 3, the network hub 66 configured for a mirrored-server environment includes a plurality of inputs 32 and outputs 34 formed into input-and-output pairs 30 which sequentially assemble data packets generated by Stations 1 to N on Channels A and B of the communication media. The hub 66 also includes a workstation broadcast output 68 for transmitting data packets which have been sequentially routed through the last workstation 22 in the network (i.e., Station N) to the file servers 58.

The mirrored-server network hub 66 has a first server broadcast input 70 connected to the first file server 58 (i.e., File Server 1) and receives data packets generated by File Server 1 via Channel D. The hub 66 also has a second server broadcast input 72 connected to the second file server 58 (i.e., File Server 2) and receives data packets generated by File Server 2. The first and second server broadcast inputs 70 and 72 are respectively connected to the first and second server broadcast units 62 and 64. Upon receiving data packets from the server broadcast inputs 70 and 72, the server broadcast units 62 and 64 respectively broadcast via Channels D and E these received data packets to the workstations 22.

The Wide Area Network

The networking principles of the present invention are not limited to peer-to-peer networks or client/server networks but may be implemented in wide area networks as well. With reference to FIG. 8, a wide area network (WAN) 78 in accordance with the present invention is shown. The WAN 78 includes a plurality of local area networks (LAN) 80 in communication with a remote source 82. Each of the LANs 80 is comprised of a plurality of stations 22 in communication with a network hub 84 via communication media. The remote source 82, which may be, for example, another network, a file server, a mail server, etc., communicates with the network hub 84 of each of the LANs 80.

The stations 22 of each LAN 80 sequentially gather data packets on Channels A and B of the communication media. A LAN broadcast unit 86 of each hub 84 then broadcasts the data packets from the stations 22 to the stations 22 on Channel C. This is performed analogously to the exemplary embodiments described above.

When the remote source 82 generates data packets to be delivered to the stations 22, the remote data packets are broadcast by the remote source 82 to each of the LANs 80 in the WAN 78. A WAN broadcast unit 88 of each of the network hubs 84 receives the remote data packets from the remote source 82 and broadcasts the remote data packets to each of the stations 22 on Channel D of the communication media.

In view of the description of networking principles of the present invention provided above, the network interface cards 14 and the network hub 16 do not require specialized communication media to implement a computer network according to the present invention. Most types of cable available on the market are able to carry the reception and the delivery channels 24 and 28, which will be discussed further below. Implementation of Preferred Embodiments

With reference to Fig. 9, a network 110 includes a file server 112 in communication with a plurality of workstations 114 via a network hub 16. The file server 112 may include a processing unit or computer 118 which may incoφorate any number of devices including internal and external disk drives, microprocessors, and so on as is known in the art. Similarly, the workstations 114 each may include a processing unit or computer 120 which in turn may include internal and external disk drives, processors, and so on as is known in the art.

The network 110 further includes a plurality of network interface cards 14. The data server 112 and each of the workstations 114 is provided with a network interface card 14. The network interface card 14 may be housed inside the computers 118 and 120, as shown in FIG. 9, or provided as a separate, stand-alone unit in communication with the computers. With additional reference to Fig. 10, each of the network interface cards 14 may be in the form of a computer card with an interface bus 124 for connection with the respective computer 118 and 120. The various connections between the network interface card 14, the network hub 16, and the processor units 118 and 120 may be made with known cables, which will be discussed in detail below.

The network interface card 14 preferably has three network inputs B, C, and D and one network output A, each in the form of cable pairs. Input B is a remote input while inputs C and D are system broadcast inputs. Output A is a combined output of the network interface card 14, preferably comprising cable pair 1 of the connector. Each of these connections has a specific and designated purpose in the wide bandwidth technology of the present invention.

The network interface card 14 may include a remote input first-in-first-out (FIFO) memory device 126 in communication with remote input B, and a local data FIFO memory device 128 in communication with the processor of the server 112 or the respective workstation 114 at which the network adapter 14 is located. The network adapter 14 may further include a microprocessor or state machine 130 in communication with the FIFO memory devices 126 and 128. The combined output A is output from the state machine 130. Accordingly, data packets that are input to the network interface card 14 through remote input B are combined in the state machine 130 with locally transmitted data from the local FIFO 128 and then sent to the hub 16 via the combined output A.

Turning briefly to conventional networking arrangements, Ethernet-type schemes synchronize data transmissions from one computer to other computers on the local area network through a technique of data collision detection and recovery. In these contention-type networks, a considerable percentage of network bandwidth can be lost through data collisions when the network is under heavy utilization.

The networking technology of the present invention, however, is a contentionless protocol. Data collisions are prevented by a loop-through approach which is accomplished in the network interface card 14 or hub 16. Data packets from other computers or workstations 114 enter the adapter 14 through remote input B. These incoming packets are stored in the remote input FIFO memory device 126. The remote input memory device 126 is sized with adequate depth to enable the temporary storage of the largest packet supported by the network 110. Local data, that is, data generated by the workstation 114 at which the specific network adapter 14 is located, to be transmitted is loaded into the local data FIFO memory device 128 through the interface bus 124 with the computer unit 118 or 120. The task of managing the synchronization of packets to be transmitted is accomplished by the microprocessor or state machine 130.

When one of the network interface cards 14 begins to receive a remote packet of data at remote input B, the state machine 130 detects the receipt of the packet of data by detecting a change in the status of the "empty" flag of the FIFO memory device 126, thereby signaling the beginning of the arrival of an incoming data packet. Upon such detection, the state machine 130 immediately begins transmitting, via combined output A, the incoming packet. In those instances when the local machine or workstation has created a packet of data for transmission and where the empty flag of the remote input FIFO memory device 126 indicates that no remote packet of data is being received, the state machine 130 then transmits a local packet at the local memory device 128 via the combined output A.

If a remote packet of data is received by the state machine 130 from the remote FIFO 126 while the state machine 130 is in the process of transmitting a local packet of data from the local FIFO 128, the remote packet is stored in the remote input FIFO 126 and is transmitted immediately upon completion of the transmission of the local packet. As the combined output A preferably transmits at the same data rate as remote input B and as the remote input FIFO has the capacity to store an entire incoming packet of data, data overflow does not occur. By this method, local packets of data are insertable into the data stream to be output from output A. System broadcast inputs C and D have a special and unique function within the wide bandwidth network 110. The adapter 14 has the ability of inputting data through either input C or D, one at a time, selectable under software control (stored on and activated by, for example, the processor units 118 or 120). As will be shown later, the two system broadcast inputs C and D input data to the local machine (i.e. , the server 112 or workstation 114 at which the adapter is located) and can be used in a diversity of methods depending on the requirements and restraints of the individual installation.

With further reference to FIG. 9, the wide bandwidth network interface card 14 is shown installed in a LAN configuration. In this exemplary embodiment, one of the workstations 114, for example, workstation 1, initiates a "chained" data stream. Local data generated at workstation 1 is transmitted over the network 110 by workstation 1 and travels to the hub 16, where the workstation 1 local data is rerouted or "combined" to remote input B of the network adapter 14 located at workstation 2. As described in above, workstation 2 synchronizes the transmission of workstation 1 data with its own local data transmission, sending the combined output of workstation 1 and 2 local data to the hub 16 via combined output A where this combined data is chained to workstation 3. Workstation 3 in turn synchronizes the transmission of workstation 1 and 2 data with its own local data transmission, sending the combined output of workstation 1, 2, and 3 local data to the hub 16 via combined output A. In other words, transmissions from the combined output A of workstation 3 contain the combined queries or transmissions of all the workstations 114 of the network 110, which workstations 114 number three in this example. The workstation 3 transmissions are in turn chained through the hub 16 to the data server 112.

Although in many installations the data transmissions from the workstations 114 are addressed to server 112, the specifically addressed data transmissions are not "picked-off" the data stream at this time. Rather, these combined transmissions are synchronized with the output A from the server 112, the combined result then returning to the network hub 16. The hub 16 includes a system broadcast amplifier 132 which receives the combined transmissions from the data server 112 and outputs the system broadcast transmission D. An exemplary process for addressing data packets may include the following steps. Prior to the transmission of each packet, the computer loads into the network interface card 14 the destination and source MAC addresses. A MAC address is a unique number assigned to every network interface card 14. The first 48 bits of the MAC address are the vendor's ID assigned to that vendor by the I.E.E.E. The last 48 bits are a distinguishing number for each board assigned by the manufacturer of the board. The sender's source address is stored in permanent memory on the network interface card 14. During the start-up and initialization procedure, the computer reads the MAC address of the network interface card 14 connected thereto. The computer then loads the address into a register at an appropriate time. From the data loaded in the register, the network interface card 14 creates and sends the addressed data packet.

An exemplary process for receiving data packets may include the following steps. The network interface card 14 receives an address from the computer for the desired packet. Most of the time, this address would be the local MAC address of the particular network interface card 14. At other time, other addresses may be used. For example, a promiscuous mode utilized by network-monitoring products is programmed to receive all packets with all labels. There may be another address for broadcast packets. After the network interface card 14 is programmed with a receive address, the network interface card 14 then automatically monitors packet traffic and captures only those packets which fulfill the address requirement of the computer. Returning to the embodiment shown in FIG. 9, in wide bandwidth terminology, "system broadcast" or WideCast™ is used to refer to a signal or transmission which is simultaneously sent to a number of computers, workstations, servers, etc. In the example illustrated in FIG. 9, system broadcast output D is delivered simultaneously as system broadcast input D to each of the workstations 114 and to the server 112. The system broadcast output D signal is delivered to every computer connected to the hub 16. (This connection has been omitted from the drawings for the sake of clarity.) System broadcast output D is preferably transmitted over pair four of the unshielded twisted pair (UTP)-5 cable connecting each computer unit 118 and 120 (i.e., the adapter 14) to the hub 16. Even in installations with system broadcast channels C and D, only a single UTP-5 cable is required to provide all four data communications paths of the system 110.

As packets of data are received at each computer 112 and 114 via system broadcast D, the network interface card 14, which monitors all of the packet transmissions on the channel, selects and retrieves those packets of data addressed to the local computer at which the particular network interface card 14 is located. It is by this method that round-trip communications are accomplished in the wide bandwidth environment of the present invention.

Referring to FIG. 11, there is shown a wide bandwidth network 134 in which a pair of hubs, a server hub 136 and a workstation hub 138, are provided, as well as more than one server 112. In this embodiment of the wide bandwidth network technology of the present invention, the transmissions of the workstations 114 have been separated from the transmissions of the servers 112. In the embodiment of FIG. 9, the bandwidth of a single hub 16 is limited to the combined transmission of all workstations 114 and servers 112. By dividing the chained outputs of the workstations 114 from the chained outputs of the servers 112 as shown in the embodiment of FIG. 11 , the available bandwidth is doubled. Further, the server hub 136 includes a system broadcast C amplifier 140 which transmits system broadcast output C to all the servers 112 connected to the server hub 136, and the workstation hub 138 includes a system broadcast D amplifier 142 which transmits system broadcast output D to all the workstations 114 connected to the workstation hub 138. FIG. 12 illustrates a simplified wiring diagram of a wide bandwidth hub 144 according to the present invention. The wide bandwidth hub 144 provides a simple method of connecting up to 24 computers into a LAN by tying together sequentially inputs and outputs of the hub 144 (respectively represented by reference numerals 1 to 24), thereby connecting the combined output of one of the computers of the LAN to the remote input of another one of the computers of the LAN. It is also possible to interconnect or cascade multiple hubs 144 through the utilization of the special input/output connections. Since the necessity of detecting collisions has been eliminated from the WideBand design, the Ethernet limitation of hub interconnections has been eliminated. If one of the hub ports (1 to 24) is vacant or unconnected, the chaining from channel to channel is broken. This method provides the user with the capability of dividing networks into smaller segments to increase bandwidth in implementations such as the dual-hub embodiment illustrated in FIG. 11. Alternatively, means may be provided to automatically bypass unconnected channels with a bypass relay.

The WideBand hub 144 is designed in such a way that numerous innovative approaches of implementation are possible. FIG. 13 illustrates another exemplary embodiment of the wide bandwidth network technology of the present invention. A wide area network 150 includes a plurality of LANs 152 each including a combination of workstations and servers. A hub 154 and a corresponding number of routers 156 are connected into a backbone configuration. Each of the routers 156 has a network interface card 14 analogous to that described above in reference to FIG. 10. In this embodiment, the hub 154 includes a system broadcast amplifier 158 which transmits the combined data stream of all of the LANs 152 to each of the routers 156 connected to the hub 154.

With reference to Fig. 14, another implementation of the wide bandwidth technology of the present invention is illustrated. The network of Fig. 14 is similar to that of FIG. 13 with the addition of access to the Internet, represented by reference numeral 160, via an Internet server 162 including a network adapter 14. In this installation, a high-speed Internet interface such as a Tl or a T3 is coupled, full speed, all the way to the desktop.

FIG. 15 illustrates a wide area network 164 in accordance with the present invention. The wide bandwidth components are connected into wide area networks in which system broadcast D is utilized for distribution of local area network traffic and in which system broadcast C provides a high-speed, enterprise-wide channel which greatly simplifies E-mail installations and accelerates wide area communications via a mail server system 166.

More specifically, each of the networks includes a combination of servers and workstations, as well as a hub 168 including a system broadcast D amplifier 170 corresponding to combined data streams of the local area network and a system broadcast C amplifier 172 corresponding to the mail server 166. When workstations and servers of the local area networks are not monitoring system broadcast input D to retrieve local data by means of the network interface cards 14 contained therein, the network interface card 14 monitors system broadcast input C to retrieve locally addressed mail and message packets transmitted from the mail server system 166.

The implementation of the wide bandwidth network 174 of the present invention illustrated in FIG. 16 depicts two servers 112 operating in parallel or in a "mirrored" mode. All of the queries to the servers 112 are delivered simultaneously to both servers 112 over system broadcast ouφut C from a server hub 176. The ouφut of file server 112 is delivered to each of the workstations 114 over system broadcast channel C from a workstation hub 178, whereas the ouφut transmissions of file server 112 are delivered to each of the workstations 114 via the system broadcast channel D of the workstation hub 178.

When the wide bandwidth technology of the present invention is configured in this manner, both hubs 176 and 178 operate in parallel, processing requests and responding to the workstations 114. Significantly, however, both servers 112 are completely independent and redundant, even down to the cable pair over which the server data is delivered to the workstations 114. In the event that one of the file servers 112 were to malfunction and one of the workstations 114, therefore, were not to receive a response to a request, the workstation 114 could then independently switch from input channel D to input channel C and continue processing with the still functioning server 112.

With reference to FIG. 17, yet another exemplary embodiment of the present invention is shown. This wide bandwidth network 180 includes a video source 182 connected to a network hub 184 via input port B. A second video source 186 is connected to the next port, continuing down the chain as discussed in reference to FIG. 17. As video data is time sensitive, packets of data can automatically be sent over the network 180 in synchronization with the demands of the video capture device as shown.

Having discussed exemplary embodiments of the wide bandwidth network technology of the present invention thus far, more specific implementations of the technology will now be discussed. The synchronization of data packets at the workstations 114 can be accomplished utilizing FPGA technology such as the Cypress 384, 385, and 387 FPGAs. These devices are fast and user programmable. They can also simultaneously perform data encryption functions as disclosed in U.S. patent application serial No. 08/430,942 filed on April 26, 1995, which application is incoφorated herein by reference and by appending a copy of the application hereto.

As discussed above, from the FIFO memory devices 126 and 128 of the network adapter 14, data is transmitted serially. One way to accomplish this serial transmission is by transferring the data into the parallel input of a device such as the Cypress CY7B923 which performs 8B/10B coding and which creates the differential high-speed serial output. Details on various coupling and termination techniques for serial communication are discussed in the CY7B923 and 933 Data Book.

Preferable technical specifications of the present invention follow. Wideband data is transmitted from the server 112 to the workstations 114 at a bit rate of preferably 333 Mbps over each twisted pair of UTP-5 cables. Eight-bit data is converted into a 10-bit format to maintain clock synchronization, to provide a method of hardware error detection, and to enable the transmission of control characters. The decoding of 10-bit data back to its original 8-bit format on the receiving side results in a useful data rate throughput of 267 Mbps per cable pair or 33 megabytes per second (MBps). Since three or the four twisted pairs of the UTP-5 cable are utilized to transfer data by the wide bandwidth technology, the total data rate is preferably 1.0 Gbps. The fourth pair is utilized for data synchronization. The preferred technical specifications of the wide bandwidth technology of the invention are outlined in TABLE 1.

TABLE 1 Data Rate: 1,000 Mbps (over UTP-5 cable)

800 Mbps usable

Byte Rate: 100 MBps

33 MBps/cable pair

Raw Bit Rate: 333 Mbps/cable pair (10-bit bytes) Encoding: 8B/10B

Ouφut Signal: 100K ECL serial

Bit Error Rates: IO^"12 or better Wideband transmission distances over UTP-5 cable are 100m (330 ft). Transmission distances of other types of cabling and fiber are presented in TABLE 2.

TABLE 2

Cable Type Uncompen sated C o m p e n s a t e d Transmission Transmission

UTP-5 Unshielded Twisted Pair 50 m (165 ft) 100 m (330 ft)

UTP-3 Unshielded Twisted Pair 18 m (60 ft) Not

Recommended RG-59 A/U Coax (75 ohm) 75 m (250 ft) 150 m (500 ft) RG-62 A/U Coax (93 ohm) 98 m (325 ft) 200 m (650 ft)

Fiber optic LED driver 1,000 m (3,300 ft) n/a

The trappings on the cables range from metal Ethernet T-connectors to the simple plastic modular plugs used with unshielded twisted pair (UTP) wire. Some Ethernet cards have connectors for coaxial cable, and others provide a 15-pin socket for more complex external transceivers for fiber optic and other types of cables. Token Ring cards have a 9-pin connector for shielded twisted pair (STP) wire. However, UTP wire is becoming increasingly popular for both Ethernet and Token Ring cards. These cards have a simple plastic rectangular jack (e.g., RJ-45) similar to those found on modern telephones.

Applications requiring greater transmission distances can utilize passive equalization to increase cable length. Table 2 also provides data transmission distances for systems compensated with passive equalization.

Wideband networking is a sophisticated yet simple approach to increasing data transmission bandwidth in local and wide area networks over existing cabling. Wideband utilizes the basic technology of ATM but with modifications which make it more readily compatible with existing application software and the OSI seven-layer model. Through all its various configurations, it provides a versatile alternative in high-speed networking.

The network interface cards do not need to use copper cables. The network interface cards may be configured to read pulses of laser light sent over fiber optic cables, pulses of infrared light sent through the air, or signals imposed on radio waves. Many installations may use copper cables for most connections and intermix fiber optic or wireless alternatives to reach special stations.

The Packet-Merging Hub

An alternative embodiment to merging data packets at the network interface card is shown in FIG. 18. In addition to the plurality of computers 12, a network 200 includes a packet- merging hub 202 in communication with each of the computers 12 via a respective network interface card 204. Rather than merging data packets generated by the computers 12 at the computers themselves (i.e., at the network interface cards 14) as described above, the data packets are sent from the computers 12 to the packet- merging hub 202 to be merged into a stream of data packets which is then broadcast to all of the computers 12 in the network 200. The packet- merging hub 202 includes a plurality of ports 206 each for connecting with and receiving data packets from a respective one of the computers via a dedicated communication medium, such as a data channel 208. Each of the ports 206 is paired with and connected to a storage device, such as a first-in, first-out (FIFO) device 210. Each of the FIFO devices 210 receives and temporarily stores data packets received from one of the computers 12 via the port 206 paired therewith.

The packet-merging hub 202 further includes a merging processor 212, such as a Cypress 382 FPGA, connected to each of the FIFO devices 210. The merging processor 212 sequentially merges data packets received at each of the ports 206 into a stream of data packets. The steam of data packets includes all of the data packets generated by each of the computers 12.

The packet-merging hub 202 includes an internal bus 214 on which the stream of data packets are delivered to a broadcast ouφut 216 connected to a broadcast channel 218. The internal bus 214 is substantially a packet- merging channel provided in the network hub 202. The packet-merging hub 202 then broadcasts the stream of data packets to each of the computers 12 via the broadcast output 216 and the broadcast channel 218. The packet-merging hub 202 preferably includes an amplifier 220 for amplifying the stream of data packets prior to broadcast on the broadcast channel 218.

With additional reference to FIG. 19, each of the network interface cards 204 includes a local data input 222 connected to one of the computers 12 and a local data ouφut 224 connected to one of the data channels 208. The data input 222 receives data packets generated by the computer 12 connected thereto, and the data output 224 provides the generated data packets to the network hub 202 via the data channel 208.

Each of the interfaces 204 also includes at least one broadcast input 226 connected to a broadcast ouφut 228 with a broadcast processor 230 provided therebetween. The broadcast input 226 is connected to the broadcast channel 218 and receives the stream of data packets. The broadcast processor 230 then determines which of the data packets are addressed to the local computer 12 and provides such data packets to the broadcast output 228 for delivery to the local computer 12 for further processing.

Each of the interfaces 204 preferably includes a local storage device 231 connected between the local data input 222 and the local data output 224. The local storage device 231 is able to temporarily store data packets generated by the local computer 12 when the FIFO device 210 corresponding thereto is filled or nearly filled to capacity during peak operating conditions of the network hub 202.

More specifically, when the network hub 202 is simultaneously receiving data packets from the plurality of computers 12, data packets temporarily stored in the FIFO devices 210 may have to queue until the merging processor 212 is able to merge the temporarily stored data packets into the stream of data packets. As the FIFO devices 210 have a limited storage capacity, if data packets are being stored in one of the FIFO devices 210, waiting to be merged, and if the computer associated therewith continues to generate and transmit data packets to the queueing FIFO device 210, then there is the possibility that the FIFO device 210 will reach its storage capacity before the merging processor 212 is able to relieve the FIFO device 210 of the temporarily stored data packets.

In this case, it is preferable for the FIFO device 210 to transmit a status signal or flag to the interface 204, indicating that the FIFO device 210 is nearing or is at its storage capacity, or that the FIFO device 210 has suφassed a predetermined percentage of its total storage capacity, e.g., 95%. Upon receipt of the status signal, the interface 204 temporarily stores already-generated data packets in the local storage device 231 until the FIFO device 210 has unloaded the stored data packets into the stream of data packets. It is preferable to send the status signal from the network hub 202 to the interface 204 on the same data channel 208 connecting the port 206 with the data output 224. In addition, the merging processor 212 preferably monitors each of the FIFO devices 210 to determine which of the FIFO devices 210 are nearing storage capacity and, responsively, to merge the data packets from such FIFO devices 210 into the stream of data packets expeditiously.

In this status-signal embodiment, the data output 224 of the interface 204 is included in a data port connected to the data channel, which data port also includes a signal input for receiving the signal from the network hub 202. Accordingly, each of the data channels 208 is able to deliver data packets from the interfaces 204 to the network hub 202 and is able to deliver the capacity-indication signal from the network hub 202 to the interface 204, which two-way communication is indicated by the double-headed arrows of the data channels 208 in FIG. 20. To do so, the data channels 208 are preferably cable pairs, with one cable dedicated to the transmission of data packets and the other cable dedicated to the transmission of the status signal.

Depending upon the particular topology of the network 200 to be implemented, each of the interfaces 204 may also include a second broadcast input 232 connected to another broadcast channel 234 and the broadcast processor 230. The broadcast channel 232 may be connected to a remote source, such as the Internet, a video server, or an electronic mail system, for receiving a remote stream of data packets. The broadcast processor 230 receives the remote stream of data packets, determines which of the remote data packets are addressed to the local computer, and then provides such data packets to the broadcast output 228 for deliver to the local computer 12.

With additional reference to FIGS. 20 and 21, a plurality of the network hubs 202 may be serially connected into a multi-hub network 240. In order to do so, each of the network hubs 202 further includes an expansion port 242 which is connected to the internal bus 214 of the hub 202. The expansion port 242 is provided with the same stream of data packets as that provided to the broadcast ouφut 216 of each of the hubs 202.

To cascade the network hubs 202, the expansion port 242 of a first network hub is connected to one of the ports 206 of a second network hub, thereby providing the stream of data packets from the first network hub to the second network hub, indicated by reference numeral 244 in FIG. 21. The merging processor 212 of the second network hub 202 then merges the stream of data packets 244 from the first network hub 202 with the data packets received at its other ports 206, generating a combined stream of data packets.

The expansion port 242 of the second network hub may then be connected to one of the ports 206 of a third network hub 202, thereby providing the combined stream of data packets to the third network hub 202, as indicated by reference numeral 246. The merging processor 100 of the third network hub 202 then merges the combined stream of data packets 246 with data packets received at its other ports 206. The stream of data packets merged by the third network hub 202 may then be broadcast to all of the computers in the network 240 via the broadcast channel 218.

The network 240 with cascaded network hubs 202 may also be connected to a remote source 248, such as the Internet, a wide area network, or an electronic mail system, for receiving a remote stream of data packets 250 from the remote source 248. Accordingly, each of the network hubs 202 preferably include a first broadcast input 252 and a second broadcast input 254. As shown, the remote source 248 is connected to the first broadcast input 252. The second broadcast input 254 may then be connected to another remote source for further expansion of the network 240.

In the specific embodiment shown in FIG. 21, the expansion port 242 of the third network hub 202 receiving the combined stream of data packets 246 is connected to the second broadcast input 254 by a jumper cable 256. By do so, the third network hub 202 is able to broadcast to all of the computers in the network 240 both the stream of data packets from all the computers in the network 240 and the remote stream of data packets 250 from any remote source 248 that may be connected to the network 240. Each of the network hubs 202 may also include first and second broadcast amplifiers 258 and 260 for amplifying the respective streams of data packets to be broadcast over the two broadcast channels 218 and 234.

Specific details regarding the implemetation of the above-described exemplary embodiments, as well as other embodiments according to the networking principles of the present invention, are discussed at length in a book entitled WideBand Networking by Dr. Roger E. Billings, which is available from the International Academy of Science of Independence, Missouri.

Those skilled in the art will understand that the preceding exemplary embodiments of the present invention provide foundation for numerous alternatives and modifications. These other modifications are also within the scope of the wide bandwidth network technology of the present invention. Accordingly, the present invention is not limited to that precisely shown and described herein.

Claims

CLAIMSWhat is claimed is:

1. A computer network comprising: a) a plurality of computers, each having a unique address and being capable of generating addressed data packets intended for delivery to another one of said computers, each of said computers including an interface having a data ouφut and a broadcast input; b) a plurality of data channels, each of which is connected to said data ouφut of one of said computers, each of said data channels for receiving addressed data packets generated by said one computer; c) a broadcast channel connected to said broadcast input of each of said computers; and d) a network hub including (1) a plurality of ports each of which is connected to a respective one of said data channels for receiving addressed data packets and (2) a broadcast ouφut connected to said broadcast channel; said network hub for sequentially merging addressed data packets received at each of said ports into a stream of data packets and for providing said stream of data packets to said broadcast channel for delivery to each of said computers.

2. The computer network of claim 1 further comprising a second broadcast channel wherein: said interface of each of said computers has a second broadcast input connected to said second broadcast channel; and said network hub further includes: a broadcast port for receiving a remote stream of data packets from a remote source; and a second broadcast ouφut connected to said broadcast port and said second broadcast channel for providing said second broadcast channel said remote stream of data packets for delivery to each of said computers.

3. The computer network of claim 1 wherein the computer network comprises a plurality of said network hubs; each of said network hubs further including an expansion port for providing said stream of data packets; and said expansion port of one of said network hubs being connected to one of said ports of another one of said network hubs.

4. The computer network of claim 3 wherein the plurality of network hubs are serially connected together.

5. The computer network of claim 1 wherein said network hub further includes: a) a plurality of storage devices each of which is connected to a respective one of said ports, each of said storage devices for receiving and temporarily storing said addressed data packets generated by said respective computer; b) a processor connected to each of said storage devices for sequentially merging addressed data packets temporarily stored by each of said storage devices into a stream of data packets; and c) an internal bus connected to each of said storage devices and to said broadcast ouφut for delivering said stream of data packets to said broadcast ouφut.

6. The computer network of claim 5 wherein each of said interfaces further includes a local storage device connected to said data ouφut for temporarily storing addressed data packets generated by said computer and for providing addressed data packets to said data ouφut.

7. The computer network of claim 6 wherein said network hub communicates with said interface of each of said computers via the corresponding data channel, said local storage device temporarily storing addressed data packets upon receiving a signal from said network hub.

8. The computer network of claim 6 wherein each of said storage devices generates a signal indicative of the capacity of said storage device, said signal being generated when a predetermined amount of said storage device is filled with temporarily stored addressed data packets, said signal being sent to said port corresponding to said storage device which generated said signal; each of said interfaces including a signal input connected to said local storage device and to said data channel connected to said data ouφut of said same interface, said signal input for receiving said signal from said port connected to said data channel; said local storage device temporarily storing generated data packets upon receiving said signal.

9. The computer network of claim 1 wherein each of said interfaces further includes a broadcast processor connected to said broadcast input for receiving said stream of data packets and for providing to the computer data packets from said stream of data packets which are addressed to said computer.

10. The computer network of claim 1 wherein each of said interfaces further includes a local storage device connected to said data ouφut for temporarily storing addressed data packets generated by said computer and for providing addressed data packets to said data ouφut.

11. A network hub for connecting a plurality of computers and communication media in a network, each of the computers being capable of generating data packets, the communication media including reception media and delivery media for connecting to each of the computers, the network hub comprising: a) a plurality of ports, each for connecting to the reception media and for receiving, via the reception media, data packets generated by one of the computers; b) a plurality of storage devices, each connected to one of said ports for receiving and temporarily storing data packets generated by the one computer; c) a processor connected to each of said storage devices for sequentially merging data packets temporarily stored by each of said storage devices into a stream of data packets; d) a broadcast ouφut for connecting to the delivery media and for providing the stream of data packets to the delivery media for delivery to each of the computers; and e) an internal bus connected to each of said storage devices and to said broadcast ouφut for delivering the stream of data packets to said broadcast ouφut.

12. The network hub of claim 11 further comprising a broadcast amplifier connected to said internal data bus for amplifying the stream of data packets prior to delivery to the broadcast ouφut.

13. The network hub of claim 11 further comprising an expansion port connected to said internal bus and being connectable to the communication media; said expansion port for receiving the stream of data packets from said internal data bus and for providing the stream of data packets for delivery to the communication media.

14. The network hub of claim 13 further comprising: a broadcast input for receiving a remote stream of data packets from a remote source; and a second broadcast ouφut connected to said broadcast input for connecting to the delivery media and for providing the delivery media the remote stream of data packets.

15. The network hub of claim 13 further comprising: a first broadcast input and a second broadcast input for respectively receiving a first remote stream of data packets and a second remote stream of data packets from remote sources; and a second broadcast ouφut connected to said internal bus for connecting to the delivery media; said first broadcast input and said second broadcast input being respectively connected to said broadcast ouφut and said second broadcast ouφut; the stream of data packets being sequentially merged with the first and second remote streams of data packets prior to being provided to said broadcast ouφuts; and said broadcast ouφuts for respectively providing the merged streams of data packets to the delivery media for delivery to each of the computers.

16. The network hub of claim 15 further comprising a first amplifier provided between said first broadcast input and said broadcast ouφut, and a second amplifier provided between said second broadcast input and said second broadcast ouφut; said amplifiers for respectively amplifying the merged streams of data packets.

17. The network hub of claim 11 wherein the network hub is mounted on a single card.

18. An interface for interfacing a computer to a network including a plurality of computers, the computer having a unique address and being capable of generating addressed data packets intended for delivery to another computer on the network, the interface comprising: a) a data input for receiving addressed data packets generated by the computer; b) a data ouφut connected to said data input for delivering addressed data packets to the network; c) a broadcast input for receiving from the network a stream of addressed data packets including addressed data packets generated by any of the computers in the network; d) a broadcast processor connected to said broadcast input for detecting data packets from the stream of addressed data packets which bear the unique address of the computer; and e) a broadcast ouφut connected to said broadcast processor for delivering said detected data packets to the computer.

19. The interface of claim 18 further comprising a second broadcast input connected to said broadcast processor for receiving from the network a second stream of addressed data packets from a remote source; said broadcast processor detecting data packets from the second stream of addressed data packets which bear the unique address of the computer.

20. The interface of claim 18 further comprising a local storage device connected to said data input and said data ouφut for temporarily storing addressed data packets generated by the computer.

21. A method for communicating data packets in a network including a plurality of computers, each of the computers being connected to a network hub by a respective delivery channel and a broadcast channel, the method comprising the steps of: generating addressed data packets by the plurality of computers; tranmsitting said generated data packets to the network hub via the delivery channel; receiving said transmitted data packets at the network hub; sequentially merging said received data packets into a stream of data packets at the network hub; and broadcasting said stream of data packets from the network hub to each of the computers via the broadcast channel.

22. The method of claim 21 further comprising the step of: temporarily storing said received data packets at the network hub prior to sequentially merging said received data packets into said stream of data packets.

23. The method of claim 21 further comprising the step of: amplifying said stream of data packets at the network hub prior to broadcasting said stream of data packets.

24. The method of claim 21 further comprising the steps of: receiving a remote stream of data packets from a remote source at the network hub via another delivery channel; and broadcasting said remote stream of data packets to each of the computers via another broadcast channel.

25. The method of claim 21 further comprising the step of: transmitting said stream of data packets to another network hub.

26. The method of claim 21 further comprising the steps of: receiving a remote stream of data packets from a remote source at the network hub via another delivery channel; sequentially merging said remote stream of data packets with said stream of data packets; and broadcasting said merged stream of data packets to each of the computers via the broadcast channel.

27. A computer network comprising: a) a plurality of computers, each having a unique address and being capable of generating addressed data packets intended for delivery to another one of said computers, each of said computers including an interface having a data ouφut and a broadcast input; b) a packet-merging channel; c) a plurality of storage devices, each being connected to said data ouφut of said interface of one of said computers and to said packet-merging channel, each of said storage devices for receiving addressed data packets generated by said one computer, for temporarily storing said received addressed data packets, and for merging said temporarily stored addressed data packets into a stream of data packets on said packet- erging channel; d) a broadcast channel connected to said broadcast input of each of said computers and in communication with said packet-merging channel, said broadcast channel for receiving from said packet-merging channel said stream of data packets and for delivering to each of said computers said stream of data packets.

28. The computer network of claim 27 wherein said plurality of storage devices are disposed on a network hub.

29. The computer network of claim 27 further comprising a network hub; said plurality of storage devices and said packet-merging channel being disposed on the network hub; said network hub having a broadcast ouφut connected to said packet-merging channel and said broadcast channel; said network hub delivering said stream of data packets to said broadcast channel via said broadcast ouφut.

30. The computer network of claim 27 wherein said storage devices are respectively disposed on said interfaces of said computers.

31. An addressed packet network with separate packet assembly and packet broadcast channels comprising: a) a plurality of computers, each having a unique address, being capable of generating addressed data packets intended for delivery to another computer on the network, each computer including:

(1) a packet assembly input for receiving addressed data packets from another computer;

(2) a packet assembly ouφut for delivering addressed data packets to another computer; (3) a packet broadcast input for receiving addressed data packets; and

(4) an interface connected to said packet assembly input, said packet assembly ouφut, and said packet broadcast input, said interface for:

(a) merging addressed data packets received at said packet assembly input with addressed data packets generated by the computer into a merged stream of addressed data packets;

(b) delivering said merged stream of addressed data packets to said packet assembly ouφut;

(c) detecting addressed data packets from said packet broadcast input which bear the unique address of the computer; (d) delivering the detected packets to the computer for further processing; b) a packet assembly channel for assembling addressed data packets generated by all of said computers, said packet assembly channel connecting each of said computers together in a sequential chain beginning with a first of said computers and ending with a last of said computers, said chain being formed by connecting the packet assembly ouφut of each of said computers, except the last of said computers, to the packet assembly input of the next computer in sequence through a packet communication connection; and c) a packet broadcast channel consisting of a packet communication connection between the packet assembly ouφut of the last of said computers and the packet broadcast inputs of all of said computers.

32. An interface for interfacing a computer to a computer network having separate packet assembly and packet broadcast channels, the computer having a unique address and being capable of generating addressed data packets intended for delivery to another computer on the network, said interface comprising: a) a packet assembly input for receiving addressed data packets from another computer on the network on the packet assembly channel; b) a packet assembly ouφut for delivering addressed data packets to another computer on the network on the packet assembly channel; c) a packet broadcast input for receiving addressed data packets from the network on the packet broadcast channel; and d) an interface connected to said packet assembly input, said packet assembly ouφut, and said packet broadcast input, said interface for:

(1) merging addressed data packets received at said packet assembly input with addressed data packets generated by the computer into a merged stream of addressed data packets; (2) delivering said merged stream of addressed data packets to said packet assembly ouφut;

(3) detecting addressed data packets from said packet broadcast input which bear the unique address of the computer; and

(4) delivering the detected data packets to the computer for further processing.

33. A hub for communicating addressed data packets among a plurality of computers in a network via communication media, the plurality of computers, each having a unique address, being capable of generating addressed data packets intended for delivery to another computer on the network, the communication media including a packet reception channel and a packet broadcast channel, said hub comprising: a) a sequential interface for sequentially routing addressed data packets through the plurality of computers and through a last computer via the packet reception channel, the sequential interface including:

(1) a plurality of inputs each for receiving, via the packet reception channel, addressed data packets from a computer in the network; and

(2) a plurality of ouφuts each for providing, via the packet reception channel, addressed data packets to a computer in the network; and b) a broadcast interface for broadcasting addressed data packets generated by the plurality of computers to the plurality of computers via the packet broadcast channel, the broadcast interface including:

(1) a broadcast ouφut connected to the sequential interface for receiving addressed data packets which have been sequentially routed through the last computer, and for providing, via the packet broadcast channel, addressed data packets received at the broadcast ouφut to the plurality of computers.

34. A computer network comprising: a) communication media including a reception medium and a delivery medium; b) a plurality of computers including a first computer and a last computer, each computer being capable of generating data, the plurality of computers being configured in a sequential chain of computers such that, via the reception medium, each computer except the first computer communicates with a preceding computer and each computer except the last computer communicates with a following computer; and c) a plurality of network interface cards each for connecting one of computers to the communication media, the reception medium sequentially routing data generated by a computer in the chain of computers through the network interface cards connected to the computers following the computer which generated the data, the delivery medium receiving from the reception medium data sequentially routed through the network interface card connected to last computer in the chain of computers, each network interface card including:

(1) a local input connected to a computer in the chain of computers, the local input for receiving data generated by said computer;

(2) a remote input connected to the reception medium, the remote input for receiving, via the reception medium, data generated by any computer preceding said computer in the chain of computers;

(3) a remote ouφut connected to the local input, to the remote input, and to the reception medium, the remote ouφut for providing data received at the local input and data received at the remote input to the reception medium;

(4) a broadcast input connected to the delivery medium, the broadcast input for receiving, via the delivery medium, data sequentially routed through the network interface card connected to the last computer in the chain of computers; and (5) a local ouφut connected to the broadcast input and to said computer, the local ouφut for providing data received at the broadcast input to said computer.

35. The computer network of claim 34 wherein each of the network interface cards further comprises: a) a second broadcast input for connecting to the delivery medium and for receiving, via the delivery medium, data generated by any of the computers and sequentially routed through the last computer in the chain of computers; and b) a second local ouφut connected to the second broadcast input, the local ouφut for connecting to said computer and for providing data received at the second broadcast input to said computer.

36. The computer network of claim 34 wherein each of the network interface cards further comprises: a) a second broadcast input for connecting to the communication media and for receiving, via the communication media, data generated by a computer other than the computers in the chain of computers; b) a second local ouφut connected to the second broadcast input, the local ouφut for connecting to said computer and for providing data received at the second broadcast input to said computer.

37. The computer network of claim 34 wherein each of the network interface cards further comprises: a processor connected to the local input, to the remote input, and to the remote ouφut, the processor for sequentially transmitting data received at the local input and data received at the remote input to the remote ouφut.

38. The computer network of claim 34 wherein each of the network interface cards further comprises: an interface bus for connecting to a computer; the local input and the local ouφut being connected to the interface bus.

39. The computer network of claim 34 further comprising a network hub connected to the reception medium and to the delivery medium, the network hub including: a) a plurality of inputs connected to the reception medium; b) a plurality of ouφuts connected to the reception medium; each of the inputs being paired with one of the ouφuts to form an input-and-ouφut pair, each input-and-ouφut pair communicating with one of the network interface cards via the reception medium; the input of each input-and-ouφut pair being connected to the ouφut of one other input- and-ouφut pair and to the remote ouφut of one of the network interface cards; the ouφut of each input-and-ouφut pair for receiving data from the input of the one other input-and-ouφut pair connected thereto, and for providing, via the reception medium, data received thereby to the remote input of one of the network interface cards; the input of each input-and-ouφut pair for receiving data provided to the reception medium by the remote ouφut connected thereto, and for providing data received thereby to the ouφut of the one other input-and-ouφut pair connected thereto; a last input-and-ouφut pair being defined as the input-and-ouφut pair communicating with the network interface card connected to the last computer, the input of the last input-and- ouφut pair not being connected to the ouφut of another input-and-ouφut pair; c) a broadcast ouφut connected to the delivery medium and to the input of the last input-and-ouφut pair, the broadcast ouφut for communicating via the delivery medium with the broadcast input of each network interface card; the broadcast ouφut for receiving data received at the input of the last input-and-ouφut pair and for providing, via the delivery medium, data received thereby to the broadcast input of each network interface card.

40. The network hub of claim 39 further comprising: a broadcast amplifier connected between the input of the last input-and-ouφut pair and the broadcast ouφut; the broadcast amplifier for amplifying data received at the input of the last input-and- ouφut pair and for providing said amplified data to the broadcast ouφut.

41. A network interface for connecting a computer to communication media in a network, the network including a plurality of computers each of which is capable of generating data, the communication media including a reception medium and a delivery medium, the plurality of computers being configured in a sequential chain of computers such that, via the reception medium, each computer except a first computer communicates with a preceding computer and each computer except a last computer communicates with a following computer, the network interface comprising: a) a local input for connecting to a computer in the chain of computers and for receiving data generated by said computer; b) a remote input for connecting to the reception medium and for receiving, via the reception medium, data generated by any computer preceding said computer in the chain of computers; c) a remote ouφut connected to the local input and to the remote input, the remote ouφut for connecting with the reception medium and for providing data received at the local input and data received at the remote input to the reception medium to be delivered to the remote input of the network interface card connected to the following computer in the chain of computers; d) a broadcast input for connecting to the delivery medium and for receiving, via the delivery medium, data generated by any of the computers and provided by the remote ouφut of the network interface card connected to the last computer in the chain of computers; and e) a local ouφut connected to the broadcast input, the local ouφut for connecting to said computer and for providing data received at the broadcast input to said computer.

42. The network interface of claim 41 further comprising: a) a second broadcast input for connecting to the delivery medium and for receiving, via the delivery medium, data generated by any of the computers and provided by the remote input of the network interface card connected to the last computer in the chain of computers; and b) a second local ouφut connected to the second broadcast input, the local ouφut for connecting to said computer and for providing data received at the second broadcast input to said computer.

43. The network interface of claim 41 further comprising: a) a second broadcast input for connecting to the communication media and for receiving, via the communication media, data generated by a computer other than the computers in the chain of computers; b) a second local ouφut connected to the second broadcast input, the local ouφut for connecting to said computer and for providing data received at the second broadcast input to said computer.

44. The network interface of claim 41 further comprising: a processor connected to the local input, to the remote input, and to the remote ouφut, the processor for sequentially transmitting data received at the local input and data received at the remote input to the remote ouφut.

45. The network interface of claim 41 wherein: the network interface is mounted on a card having an interface bus for connecting to a computer; the local input and the local ouφut being connected to the interface bus.

46. A network hub for connecting a plurality of computers and communication media into a network, each of the computers being capable of generating data, the communication media including a reception medium and a delivery medium, the network hub comprising: a) a plurality of inputs for connecting to the reception medium; b) a plurality of ouφuts for connecting to the reception medium; each of the inputs being paired with one of the ouφuts to form an input-and-ouφut pair, each input-and-ouφut pair communicating with a computer in the network via the reception medium; the input of each input-and-ouφut pair being connected to the ouφut of one other input- and-ouφut pair to form a sequential chain of input-and-ouφut pairs including a last input-and- ouφut pair; the ouφut of each input-and-ouφut pair for receiving data from the input of the one other input-and-ouφut pair connected thereto, and for providing, via the reception medium, data received thereby to the computer communicating therewith; the input of each input-and-output pair for receiving, via the reception medium, data generated by the computer communicating therewith and data provided to said computer by the ouφut paired therewith, and for providing data received thereby to the ouφut of the one other input-and-ouφut pair connected thereto; the input of the last input-and-ouφut pair for receiving data generated by the computer communicating therewith and data generated by any other computer in the network; and c) a broadcast ouφut connected to the input of the last input-and-ouφut pair and to the delivery medium, the broadcast ouφut for communicating with the plurality of computers in the network via the delivery medium; the broadcast ouφut for receiving data received at the input of the last input-and-ouφut pair and for providing, via the delivery medium, data received thereby to the plurality of computers.

47. The network hub of claim 46 further comprising: a broadcast amplifier connected between the input of the last input-and-ouφut pair and the broadcast ouφut; the broadcast amplifier for amplifying data received at the input of the last input-and- ouφut pair and for providing said amplified data to the broadcast ouφut.

48. The network hub of claim 46 wherein the network hub is mounted on a card.

49. A method for communicating data among a plurality of stations in a network, the stations being connected in the form of a chain beginning with a first station and ending with a last station which is not connected to the first station, the method comprising the steps of: sequentially routing data issued by any of the stations through the last station via the stations which follow the station issuing the data; broadcasting data sequentially routed through the last station to the plurality of stations.

50. The method of claim 49 further comprising the step of: broadcasting data issued by a remote station not connected in the chain to the plurality of stations.

51. A method for mirroring two file servers in a client/ server network including a plurality of workstations connected in a chain beginning with a first workstation and ending with a last workstation, the method comprising the steps of: a) sequentially routing data issued by any of the workstations through the last workstation; b) broadcasting data sequentially routed through the last workstation to each of the file servers; c) generating the same data by each of the file servers; and d) broadcasting the generated data on separate broadcast channels to each of the workstations.

52. A method for communicating data in a network including a plurality of workstations and at least two file servers, the plurality of workstations being connected in a chain beginning with a first workstation and ending with a last workstation, the method comprising the steps of: a) sequentially routing data issued by any of the workstations through the last workstation; b) broadcasting data sequentially routed through the last workstation to each of the file servers; and c) broadcasting data issued by each of the file servers to each of the workstations on a broadcast channel separate from each of the broadcast channels broadcasting data issued by the other file servers.

53. The method of claim 52 further comprising the step of: detecting data at each of the workstations which are intended for delivery to that workstation; and delivering the detected data to the workstation.

54. The method of claim 52 wherein step (c) comprises the steps of: merging data issued by each of the file servers with the data sequentially routed through the last workstation; and broadcasting merged data from each of the file servers to each of the workstations on a broadcast channel separate from each of the broadcast channels broadcasting merged data from the other file servers.

55. The method of claim 52 further comprising the step of: generating the same data at each of the file servers.

56. A computer network with mirrored servers comprising: a) a first file server capable of generating addressed data packets; b) a second file server capable of generating addressed data packets; c) a plurality of workstations each having a unique address and being capable of generating addressed data packets, each of said workstations including:

(1) a packet assembly input for receiving addressed data packets from another workstation;

(2) a packet assembly ouφut for delivering addressed data packets to another workstation; (3) a first server broadcast input for receiving addressed data packets from said first file server;

(4) a second server broadcast input for receiving addressed data packets from said second file server; and

(5) an interface connected to said packet assembly input, said packet assembly ouφut, said first server broadcast input, and said second server broadcast input, said interface for:

(a) merging addressed data packets received at said packet assembly input with addressed data packets generated by said workstation into a stream of workstation-addressed data packets; (b) delivering said stream of workstation-addressed data packets to said packet assembly ouφut; (c) detecting addressed data packets from either said first server broadcast input or said second server broadcast input which bear the unique address of said workstation; and (d) delivering said detected packets to said workstation for further processing; each of said file servers including:

(1) a workstation broadcast input for receiving a stream of workstation-addressed data packets;

(2) a server broadcast ouφut for delivering addressed data packets generated by said file server to each of said workstations; and

(3) an interface connected to said workstation broadcast input and said server broadcast ouφut, said interface for:

(a) receiving the stream of workstation-addressed data packets from said workstation broadcast input; (b) delivering said stream of workstation-addressed data packets to said file server;

(c) receiving addressed data packets from said file server; and

(d) providing said addressed data packets to said server broadcast ouφut; d) a packet assembly channel for assembling addressed data packets generated by all of said workstations, said packet assembly channel connecting each of said workstations together in a sequential chain beginning with a first of said workstations and ending with a last of said workstations, said chain being formed by connecting the packet assembly ouφut of each of said workstations, except the last of said workstations, to the packet assembly input of the next workstation in sequence through a packet communication connection; e) a workstation broadcast channel consisting of a packet communication connection between the packet assembly ouφut of the last of said workstations and the workstation broadcast input of each of said file servers; f) a first server broadcast channel consisting of a packet communication connection between the server broadcast ouφut of said first file server and the first server broadcast input of each of said workstations; and g) a second server broadcast channel consisting of a packet communication connection between the server broadcast ouφut of said second file server and the second server broadcast input of each of said workstations.

57. A hub for communicating addressed data packets among a plurality of workstations and two file servers in a network via communication media, the plurality of workstations and file servers being capable of generating addressed data packets intended for delivery to a workstation on the network, the communication media including a packet reception channel, a workstation broadcast channel, a first server broadcast channel, and a second server broadcast channel, said hub comprising: a) a sequential interface for sequentially routing addressed data packets through the plurality of workstations and through a last workstation via the packet reception channel, the sequential interface including: (1) a plurality of inputs each for receiving, via the packet reception channel, addressed data packets from a workstation in the network; and (2) a plurality of ouφuts each for providing, via the packet reception channel, addressed data packets to a workstation in the network; b) a workstation broadcast interface for broadcasting addressed data packets generated by the plurality of workstations to both file servers via the workstation broadcast channel, the broadcast interface including a workstation broadcast ouφut connected to the sequential interface for receiving addressed data packets which have been sequentially routed through the last workstation, and for transmitting, via the workstation broadcast channel, said received addressed data packets to both of the file servers; c) a first server broadcast interface for broadcasting addressed data packets generated by a first of the file servers to the plurality of workstations via the first server broadcast channel, the first server broadcast interface including:

(1) a first server broadcast input connected to the first file server for receiving addressed data packets generated by the first file server; and (2) a first server broadcast ouφut connected to the first server broadcast input for transmitting, via the first server broadcast channel, addressed data packets received at the first server broadcast input to the plurality of workstations; and d) a second server broadcast interface for broadcasting addressed data packets generated by a second of the file servers to the plurality of workstations via the second server broadcast channel, the second server broadcast interface including: (1) a second server broadcast input connected to the second file server for receiving addressed data packets generated by the second file server; and

(2) a second server broadcast ouφut connected to the second server broadcast input for transmitting, via the second server broadcast channel, addressed data packets received at the second server broadcast input to the plurality of workstations.

58. A method for communicating data in a wide area network including a plurality of local area networks (LANs) and a remote source, each of the LANs including a plurality of workstations connected in a chain beginning with a first workstation and ending with a last workstation, the method comprising the steps of: a) sequentially routing data issued by any of the workstations through the last workstation; b) broadcasting data sequentially routed through the last workstation to each of the workstations on a broadcast channel; c) transmitting data generated at the remote source to each of the LANs; and d) broadcasting data transmitted from the remote source to each of the workstations on a broadcast channel separate from the broadcast channel carrying the sequentially routed data.

59. The method of claim 58 further comprising the step of: detecting data at each workstation intended for delivery to the workstation from the data sequentially routed through the last workstation; detecting data at each workstation intended for delivery to the workstation from the data transmitted from the remote source; and delivering the detected data to the workstation.

60. A wide area network comprising: a) a remote source capable of generating addressed data packets, said remote source including a remote broadcast ouφut for broadcasting addressed data packets; b) a plurality of local area networks (LANs) in communication with said remote source, each of said LANs including:

(1) a plurality of workstations each having a unique address and being capable of generating addressed data packets, each of said workstations including: (a) a packet assembly input for receiving addressed data packets from another workstation; (b) a packet assembly ouφut for delivering addressed data packets to another workstation;

(c) a LAN broadcast input for receiving addressed data packets from said workstations in said LAN;

(d) a remote broadcast input for receiving addressed data packets from said remote source; and

(e) an interface connected to said packet assembly input, said packet assembly ouφut, said LAN broadcast input, and said remote broadcast input, said interface for:

(i) merging addressed data packets received at said packet assembly input with addressed data packets generated by said workstation into a stream of workstation-addressed data packets; (ii) delivering said stream of workstation-addressed data packets to said packet assembly ouφut; (iii) detecting addressed data packets from said LAN broadcast input and said remote broadcast input which bear the unique address of said workstation; and (iv) delivering said detected packets to said workstation for further processing;

(2) a packet assembly channel for assembling addressed data packets generated by all of said workstations, said packet assembly channel for connecting each of said workstations together in a sequential chain beginning with a first of said workstations and ending with a last of said workstations, said chain being formed by connecting the packet assembly ouφut of each of said workstations, except the last of said workstations, to the packet assembly input of the next workstation in sequence through a packet communication connection; and

(3) a LAN broadcast channel including a packet communication connection between the packet assembly ouφut of the last of said workstations and the LAN broadcast input of each of said workstations; and c) a remote broadcast channel consisting of a packet communication connection between the remote broadcast ouφut of said remote source and the remote broadcast input of each of said workstations.

61. A hub for communicating addressed data packets between a remote source and local area networks (LANs) in a wide area network via communication media, the LANs including a plurality of workstations being capable of generating addressed data packets intended for delivery to a workstation in the LAN, the remote source being capable of generating addressed data packets intended for delivery to a workstation, the communication media including a packet reception channel, a LAN broadcast channel, and a remote broadcast channel, said hub comprising: a) a sequential interface for sequentially routing addressed data packets through the plurality of workstations and through a last workstation via the packet reception channel, the sequential interface including:

(1) a plurality of inputs each for receiving, via the packet reception channel, addressed data packets from a workstation in the network; and

(2) a plurality of ouφuts each for providing, via the packet reception channel, addressed data packets to a workstation in the network; and b) a LAN broadcast interface for broadcasting addressed data packets generated by the plurality of workstations to each of the workstations in the LAN via the LAN broadcast channel, the broadcast interface including:

(1) a LAN broadcast input connected to the sequential interface for receiving addressed data packets which have been sequentially routed through the last workstation; and

(2) a LAN broadcast ouφut connected to the LAN broadcast input for transmitting, via the LAN broadcast channel, addressed data packets received at the remote broadcast input to each of the workstations; and c) a remote broadcast interface for broadcasting addressed data packets generated by the remote source to the plurality of workstations via the remote broadcast channel, the remote broadcast interface including:

(1) a remote broadcast input connected to the remote source for receiving addressed data packets generated by the remote source; and

(2) a remote broadcast ouφut connected to the remote broadcast input for transmitting, via the remote broadcast channel, addressed data packets received at the remote broadcast input to each of the workstations.

62. An interface for interfacing a computer to a computer network including a plurality of computers communicating via a packet assembly channel, the computers being capable of generating data packets intended for delivery to another computer on the network, the interface comprising: a) a local input for connecting to the computer and for receiving local data packets from the computer; b) a remote input for connecting to the packet assembly channel and for receiving remote data packets from another computer on the network via the packet assembly channel; c) a remote ouφut for connecting to the packet assembly channel and for delivering local and remote data packets to the packet assembly channel for transmission to another computer on the network; d) a processor connected between the remote ouφut and each of the inputs for transmitting local and remote data packets to the packet assembly channel via the remote ouφut; e) a local storage device connected between the local input and the processor for receiving local data packets from the local input and providing local data packets to the processor; and f) a remote storage device connected between the remote input and the processor for receiving remote data packets from the remote input and providing local data packets to the processor; the local storage device for temporarily storing local data packets received from the local input when the processor is receiving remote data packets from the remote storage device; and the remote storage device for temporarily storing remote data packets received from the remote input when the processor is transmitting local data packets to the packet assembly channel via the remote ouφut.

63. The interface of claim 62 wherein the local storage device releases local data packets to the processor, and the processor transmits released local data packets to the packet assembly channel; the remote storage device releasing remote data packets to the processor for tranmission to the packet assembly channel when the processor has transmitted released local data packets; the local storage device storing any unreleased local data packets until the processor has transmitted all remote data packets received at the remote input.

64. A method for merging data packets in a network interface card interfacing a computer with a network including a plurality of computers, the network interface card being capable of receiving remote data generated by one of the computers in the network and to be retransmitted to another one of the computers in the network, the computer being capable of generating local data for delivery to another computer in the network, the method comprising the steps of: a) storing local data when remote data is being retransmitted to the network; b) transmitting the stored local data to the network; c) temporarily storing remote data when local data is being transmitted to the network; and d) retransmitting the stored remote data to the network.

65. The method of claim 64 wherein: step (b) comprises the steps of: releasing local data packets; and transmitting released local data packets; and step (d) comprises the steps of: releasing temporarily stored remote data packets when released local data packets have been transmitted.

66. An interface for interfacing a computer to a computer network including a plurality of computers communicating via a packet assembly channel and a packet broadcast channel, the computers being connected in a chain beginning with a first of the computers and ending with a last of the computers, the computers being capable of generating data packets intended for delivery to another computer on the network, the interface comprising: a) a local input for connecting to the computer and for receiving local data packets from the computer; b) a remote input for connecting to the packet assembly channel and for receiving remote data packets from the computer preceding said computer in the network via the packet assembly channel; c) a remote ouφut for connecting to the packet assembly channel and for transmitting local and remote data packets to the computer following said computer in the network via the packet assembly channel; d) a broadcast input for connecting to the packet broadcast channel and for receiving data packets from said last of the computers in the network; e) a broadcast ouφut connected to the broadcast input for connecting to said computer and for delivering data packets received at the broadcast input to said computer; f) a processor connected between the remote ouφut and each of the inputs for transmitting local and remote data packets to the packet assembly channel via the remote ouφut; g) a local storage device connected between the local input and the processor for receiving local data packets from the local input and providing local data packets to the processor; and h) a remote storage device connected between the remote input and the processor for receiving remote data packets from the remote input and providing local data packets to the processor; the local storage device for temporarily storing local data packets received from the local input when the processor is receiving remote data packets from the remote storage device; and the remote storage device for temporarily storing remote data packets received from the remote input when the processor is receiving local data packets from the local storage device.

67. The interface of claim 66 further comprising: a second processor connected between the broadcast input and the broadcast ouφut for determining which data packets received at the broadcast input are intended for delivery to said computer.