3 4
may be retrieved for execution at those work stations devices, the program requests access via a nodal net
from file server 12. work of the present invention.
Work stations 17-19 are peripheral server work sta- A detailed description of the functional capabilities of
tions and are used primarily to provide network ser- a server root and a client root will be given in detail in
vices for the peripherals for which they are connected. 5 connection with FIGS. 3, 4, and 5, respectively, and
Thus, work station 17 is a print server work stations and with respect to a representative self-generating node
provides network services for printer 21. Likewise, network constructed in accordance with the invention
work station 18 is a scanner server work station and is shown in FIG. 5.
provides network services for scanner 22, and work FIG. 3 is a general representational view of the clientstation 19 is a facsimile server work stations and pro- 10 /server communication system of the present invention, vides network services for facsimile 23. Other periph- As shown in FIG.-3, server root node 102 is a node eral devices may also be connected to the network, and which comprises a process but also contains a list of it is possible for a single work station to service more nodes contained within the server node network. The than one peripheral device. In particular, it is possible process aspect of the server root node 102 includes for work station 17 to service more than one printer, 15 process steps for building service nodes 103. In addition, and it is possible, with appropriate equipment, for a server root node 101 is provided with communication single work station to service a variety of different types capabilities for communication to the operating system of devices. 110.
While it is ordinarily necessary to provide a dedi- Server root node 102 interfaces with the operating
cated work station to service one or more peripheral 20 system program by passing communication information
devices, in some instances this is not necessary. Thus, from/to the operating system from service node 103. (It
for example, printer 25 is connected directly to LAN is noted that the number of service nodes on a server
bus 11 via network expansion board 26 which provides nodal network is only limited by available system re
the necessary print server functions without the neces- sources and that only one service node is mentioned for
sity of dedicating a work station for those printer ser- 25 the purpose of simplifying the description.) Service
vices. node 103 advertises a particular server to clients on the
Other devices may be connected to LAN 10 and network through the operating system 110. For examindeed LAN 10 may be connected as part of a wide area pie, service node 103 may be a scanner, printer, or facnetwork ("WAN") to various backbone and transpon- simile machine. Service node 103 sends a communicader connectors. These arrangements are well known to 30 tion through server root node 102 which communicates those skilled in the art and are omitted in the interest of through operating system 110. Service node 103 probrevity, vides service information to server root node 102 which
FIG. 2 is a functional block diagram showing infor- receives queries from clients as to What services are
mation exchange according to the present invention. In available. Server root node 102 returns the service ad
FIG. 2, information exchange is illustrated between a 35 vertisements from all service nodes in the server nodal
first computer process such as an application program network tree 101 to the client.
executing from one of the work stations illustrated in Service node 103 advertises its particular function as
FIG. 1 (here, work station 16), to a second computer well as server type. Service node 103 receives service
process such as printer server executing on work station information from server topic node 104 which contains
17. It is to be understood that the computer processes 40 information regarding type of server help information,
illustrated in FIG. 2 are representative only; informa- interface information, etc. For example, server topic
tion exchange can take place between any of the devices node 104 would contain such information as the type of
illustrated in FIG. 1 such as between work stations 15 printer (i.e., the manufacturer of the printer) and the and 16 or between one of the work stations in either of proper parameters (interface language) which are re
the scanner server work station 18 or the facsimile work 45 quired to access the device.
station 19. Moreover, information exchange shown in Server topic node also creates a server job node 105 FIG. 2 is illustrated between different work stations on to manage each task. Server job node 105 creates a a local area network where the need for flexible task server item node for each item within the task requested handling is the most critical. It is to be understood, by the client. Server item node 106 contains a single however, that task handling according to the invention 50 piece of information specific to the requested task. For may occur between different computing processes example, in the case of sending a facsimile message, within the same work station, for example, between a server item node 106 may contain only one of the folword processing application program that is importing lowing: a database file name for retrieving the facsimile numerical data and a spreadsheet processing application message, routing information, or a parameter for printprogram which is providing the numerical data. 55 ing the message such as height, width or line spacing.
In the course of execution of an application program, Accordingly, server job node 105 creates as many
the services of a peripheral device are required. The server item nodes as there are parameter items for a
application program obtains those services via a single task.
device driver 31 such as printer driver, scanner driver, Upon initialization of the program of the present
or a facsimile driver. The device driver, in turn, acts as 60 invention, the self-generating server nodal network
the device which communicates between an application portion of the client/server communication system is
program and a peripheral server. built. First, server nodal network tree 101 is created
In general, the present invention provides the ability from the root node. Server root node 102 interfaces
to schedule tasks for peripheral devices 21,22,23 and 25 directly with operating system 110. Server root node
on a real time basis. The present invention dynamically 65 102 is created as a process provided with both commu
configures itself via an initialization file to support addi- nication capabilities and a listing of pointer tags which
tional peripheral devices. Accordingly, when an appli- designate server nodes of the server tree. That is, server
cation program needs access to one of the peripheral root node 101 utilizes these pointer tags to retrieve from
