WO2003007559A1

WO2003007559A1 - Content hashing in a wireless content switch

Info

Publication number: WO2003007559A1
Application number: PCT/US2002/021705
Authority: WO
Inventors: Jogen K. Pathak
Original assignee: Cyneta Networks, Inc.
Priority date: 2001-07-10
Filing date: 2002-07-10
Publication date: 2003-01-23

Abstract

A method and apparatus for transmitting packet data between a content source and a wireless client is presented herein. A wireless content switch receives the packet data and analyzes the protocol layers contained therein and extracts a pattern containing destination address and other information for the packet. The wireless content switch then hashes the extract pattern, resulting in a hashing factor. The hashing factor is used as a searching index in a hashing table to access a linked list of pattern and instruction pairs associated therewith. The linked list is then examined for the extracted pattern and the instructions that are associated with the extract pattern are selected and executed.

Description

SPECIFICATION TITLE OF THE INVENTION CONTENT HASHING IN A WIRELESS CONTENT SWITCH Cross-reference to Related Applications

This application claims the priority benefit of U.S. Provisional Application for Patent,

Serial No. 60/304,326, entitled "Content Hashing In A Wireless Content Switch," filed on

July 10, 2001, and claims the priority benefit of U.S. Patent Application Serial No.

09/928,525, entitled "Content Hashing In A Wireless Content Switch," filed on August 13, 2001 , which are hereby incorporated by reference for all purposes.

Statement Regarding Federally Sponsored Research/Development

Not Applicable. Field

The present application is directed to wireless data services and more particularly, content hashing in a wireless content switch.

Background

A wireless data network includes a wired network portion and a wireless network portion for transmitting packet data from a content source to a wireless client. Packet data from the content source is transmitted from the content source over the wired network to the wireless network associated with the wireless client. The wireless network transmits the packet data over the wireless air interface to the wireless client. The prevailing standard for the transmission of packet data over a wireless network is known as the General Packet Radio Service (GPRS).

4.1 /SP3/27066/0150/070902 While GPRS and other standards define data delivery functionality, mere delivery of raw bandwidth over wireless media without an acceptable service experience will result in limited market acceptance of wireless data in the business and consumer environments. In data networking, quality implies the process of delivering data in a reliable and timely manner with consistent precision, where the definition of reliable, timely, and precision depends on the type of traffic.

The foregoing management requires a number of performance applications which examine and operate on the data contained in the received packets. The wireless content switch examines the data packet and notifies the pertinent application. Wherein a large number of applications are required to examine and operate on the data contained in the received packets, the wireless content switch must make a fast determination of the pertinent application.

Accordingly, it would be advantageous if the wireless content switch could examine the packet and make a fast determination of the pertinent application.

4.1 /SP3/27066/0150/070902 Summary

Described herein is a method and apparatus for providing data packet information to performance applications in a wireless data services network. The data packets are received at a wireless content switch which is situated between the wired network and the wireless client. The wireless content switch examines the packets for various patterns to determine which performance applications to notify. The particular application to notify is determined by examining a lookup table which correlates the patterns with the pertinent applications. The lookup table uses a hashing algorithm which correlates a large number of pattern/pertinent application(s) pairs into a more limited number of data structures. The hashing algorithm is applied to the pattern extracted from the data packet to determine the particular data structure to examine. From the data structure, the extracted pattern is located and the pertinent application(s) associated therewith is notified.

4.1/SP3/27066/0150/070902 Brief Description of the Drawings

FIGURE 1 is a block diagram of an exemplary wireless data services network; FIGURE 2 is a block diagram of an exemplary data packet; FIGURE 3 is a block diagram of an exemplary hashing table; FIGURE 4 is a flow diagram describing the operation of the wireless content switch; and

FIGURE 5 is a block diagram describing an exemplary hardware environment.

4.1 /SP3/27066/0150/070902 Detailed Description of the Drawings

Referring now to FIGURE 1, there is illustrated a conceptual diagram of a communication system, referenced generally by the numeric designation 100, for packet data from content source 105 to a wireless client 125, and vice versa. The content source 105 is a server providing information which can comprise, for example, a web server, email server, ftp server, database server, streaming audio/video server, or an application server. The packet data is data from the content source 105 or the wireless client 125 which can comprise, for example, text, event objects, web pages, emails, downloadable files, audio files, or video files. Information from the content source 105 and the wireless client 125 is transmitted in the form of numbered data packets over a wired network 110, wherein each data packet is associated with a packet number. The wired network 110 is a packet data wireline communication system which can comprise, for example, a local area network, a wide area network, or the Internet. The wired network 110 transmits/receives the data packets to/from a wireless network 120 associated with the wireless client 125 via a wireless content switch 115.

The wireless network 120 comprises any communication network which can transmit/receive packet data over a wireless air interface. For example, the wireless network 120 can comprise cellular telephone networks, such as the Global System for Mobile Communications (GSM) or Personal Communication System (PCS), equipped to transmit packet data in accordance with the General Packet Radio Service (GPRS) or EDGE protocols. The wireless network 120 transmits/receives the packet data over the wireless air interface to/from the wireless client 125.

4.1/SP3/27066/0150/070902 The wireless content switch 115 receives GPRS tunneling protocol format packet data and can determine additional processing that may be required based upon the wireless client 125, the content source 105, and the type of content in the packet, priority data, quality of service data, multicasting functionality, or other suitable functions. An exemplary wireless content switch 115 is described in U.S. Patent Application Serial

Number 09/718,713, entitled "System and Method for Wireless Packet Data Content Switch", filed November 22, 2000. Additionally, the wireless content switch 115 supports any number of performance measurement applications which examine and operate on the data contained in the received packets. The wireless content switch 115 examines the data packet and notifies the pertinent application.

Referring now to FIGURE 2, there is illustrated block diagram of an exemplary data packet protocol stack 200. It is noted that certain details are not drawn for the purposes of simplicity. The data protocol stack includes an application layer 205, a networking layer 210, a transport layer 215, a data layer 220, and a physical layer 225. A commonly used protocol for the transport layer 215 is known as the internet protocol

(IP), while a commonly used protocol for the networking layer 210 is the transmission control protocol (TCP). The application layer 205 is the highest layer and comprises commands associated with the actual application associated with the packet. Application layers can include, for example, hypertext transmission protocol (http) for downloading web pages, file transfer program (ftp) for downloading files, or email for providing email services. The wireless content switch 115 is capable of analyzing the protocol stack 200 associated with data packets and the commands and data associated therewith. Based on the information therein, the wireless content switch 115 can determine the pertinent

4.1/SP3/27O66/015O/O7O902 applications which operate on the data contained in the data packet. The wireless content switch 115 extracts a pattern from the information contained in the data packet. The pattern is used to examine a lookup table which correlates the patterns with the pertinent application(s). Referring now to FIGURE 3, there is illustrated a block diagram of an exemplary lookup table 300. The lookup table 300 includes any number of records 305. Each record 305 is associated with a particular number between zero, "0", and n-1, where n is the total number of records 305. Those skilled in the art will recognize that the association between the particular number and the records can be made by provisioning consecutive memory words beginning at an initial address. The records can be stored in at a memory word, wherein the offset of the address of the memory word is the particular number.

Each record 305 references a data structure 307 of pattern 310a/application(s) pairs 310b, wherein each pattern identifies packets upon which the associated application(s) operate. The data structure 307 can comprise, for example, a linked list or a binary tree. The particular number associated with the record 305 is the result of a hashing algorithm applied to the patterns 310a contained therein. In an exemplary case, the hashing algorithm can simply take the modulo n function of the patterns. Each pattern 310a having the same modulo n result, k, and the associated application(s), are paired and part of the link list referred to the record 305 associated with the number k.

The foregoing lookup table 300 permits the wireless content switch 115 to perform a fast search among a relatively smaller number of records 305 to find a data structure 307 containing the pattern 310a/application(s) pair 310b. The data structure 307

4.1 /SP3/27066/0150/070902 also contains a considerably smaller number of pattern 310a/application(s) pairs 310b. The particular record 305 for a pattern is determined by performing the hashing algorithm on the pattern.

Referring now to FIGURE 4, there is illustrated a flow chart describing the operation of the wireless content switch 115. At step 405, a data packet 300 is received.

The protocol stack and the contents of the data packet 300 are examined during step 410 and a pattern is extracted during step 415. At step 420, the hashing algorithm is applied to the extract pattern, resulting in a particular number. The data structure 307 in the record 305 associated with the particular number is reviewed during step 425, and the pattern 310a/application(s) 310b pair containing the pattern is selected (step 430). At step 435, the application(s) 310b contained in the pattern 310a/application(s) 310b pair are notified.

Referring now to FIGURE. 5, a representative hardware environment for practicing the present invention is depicted and illustrates a typical hardware configuration of a computer information handling system 58 in accordance with the subject invention, having at least one central processing unit (CPU) 60. CPU 60 is interconnected via system bus 12 to random access memory (RAM) 64, read only memory (ROM) 66, and input output (I/O) adapter 68 for connecting peripheral devices such as disc units 70 and tape drives 90 to bus 62, user interface adapter 72 for connecting keyboard 74, mouse 76 having button 67, speaker 78, microphone 82, and/or other user interfaced devices such as a touch screen device (not shown) to bus 62, communication adapter 84 for connecting the information handling system to a data

4.1/SP3/27066/0150/070902 processing network 92, and display adapter 86 for connecting bus 62 to display device 88.

Although the foregoing detailed description has certain degree of particularity, it should be recognized that elements thereof may be altered by persons skilled in the art without departing from the spirit and scope of the invention. One embodiment can be implemented as sets of instructions resident in the random access memory 64 of one or more computer systems configured generally as described in FIG. 5. Until required by the computer system, the set of instructions may be stored in another computer readable memory, for example in a hard disk drive, or in a removable memory such as an optical disk for eventual use in a CD-ROM drive or a floppy disk for eventual use in a floppy disk drive. Further, the set of instructions can be stored in the memory of another computer and transmitted over a local area network or a wide area network, such as the Internet, when desired by the user. One skilled in the art would appreciate that the physical storage of the sets of instructions physically changes the medium upon which it is stored electrically, magnetically, or chemically so that the medium carries computer readable information. The invention is limited only by the following claims and their equivalents.

4.I/SP3/27O66/0150/O7O9O2

Claims

WHAT IS CLAIMED IS:

1. A method for routing a packet, said method comprising: extracting a pattern associated with the packet; determining a hashing factor associated with the pattern; and selecting instructions associated with the pattern.

2. The method of claim 1, wherein extracting the pattern associated with the packet further comprises: examining a plurality of layers associated with the packet.

3. The method of claim 1 , wherein determining the hashing factor associated with the pattern further comprises: taking a modulus operation with the pattern and a predetermined modulus operation factor.

4. The method of claim 1, wherein selecting instructions associated with the pattern further comprises: examining a linked list associated with the hashing factor.

5. The method of claim 1, wherein selecting instructions associated with the pattern further comprises: examining a binary tree associated with the hashing factor.

669614.1/SP3/27066/0150/070902

6. The method of claim 1, wherein the pattern includes an internet protocol address.

7. The method of claim 1, wherein the instructions include instructions for routing the packet.

669614 1/SP3/27066/0150/070902

8. A wireless content switch for routing packets, said wireless content switch comprising: a table comprising: a plurality of records, each of said records associated with a particular number; and wherein each of said records stores a plurality of instruction sets, each of said plurality of instruction sets associated with a particular pattern.

9. The wireless content switch of claim 8, wherein each of the plurality of instruction sets form a linked list.

10. The wireless content switch of claim 8, wherein each of the plurality of instruction sets from a binary tree.

11. The wireless content switch of claim 8, wherein each particular number is associated with the particular pattern, wherein the particular number is hashed from the particular pattern.

12. The wireless content switch of claim 11, wherein the particular number is the result of the modulus of the particular pattern by a predetermined factor.

13. The wireless content switch of claim 12, wherein the predetermined factor is the number of the plurality of records.

669614.1/SP3/27066/0150/070902

14. An article of manufacture comprising a computer readable medium, said computer readable medium storing a plurality of instructions, wherein the plurality of instructions comprise: extracting a pattern associated with the packet; determining a hashing factor associated with the pattern; and selecting instructions associated with the pattern.

15. The article of manufacture of claim 14, wherein the instructions for extracting the pattern associated with the packet further comprise instructions for: examining a plurality of layers associated with the packet.

16. The article of manufacture of claim 14, wherein the instructions for determining the hashing factor associated with the pattern further comprise instructions for: taking a modulus operation with the pattern and a predetermined modulus operation factor.

17. The article of manufacture of claim 14, wherein the instructions for selecting instructions associated with the pattern further comprises instructions for: examining a linked list associated with the hashing factor.

669614 1/SP3/27066/0150/070902

18. The article of manufacture of claim 14, wherein the instructions for selecting instructions associated with the pattern further comprises instructions for: examining a binary tree associated with the hashing factor.

19. The article of manufacture of claim 14, wherein the pattern includes an internet protocol address.

669614.I/SP3/27066/0150/070902