Method and apparatus for adaptively determining the format of data packets carried on a local area network

• US 5,696,899 A
• Filed: 11/18/1992
• Issued: 12/09/1997
• Est. Priority Date: 11/18/1992
• Status: Expired due to Term

• Current Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Original Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Inventors: Kalwitz, George A.
• Primary Examiner(s): Swann, Tod R.
• Assistant Examiner(s): Tran, Denise
• Application Number:
  US07/978,409
• Time in Patent Office: 1,847 Days
• Field of Search: 395/200, 395/500, 395/325, 395/800, 395/200.4, 395/200.12, 395/835, 395/828, 395/200.1, 395/200.11, 395/200.17, 395/200.04, 395/429-431, 370/85.13, 370/79, 370/254, 370/465-467, 370/469, 370/908
• US Class Current: 709/228
• CPC Class Codes: H04L 12/413 with random access, e.g. carrier-sense multiple-access with collision detection [CSMA-CD]
• CPC Class Codes: H04L 67/00 Network arrangements or protocols for supporting network services or applications user-to-user messaging H04L51/00; network arrangements, protocols or services for supporting real-time applications in data packet communications networks H04L65/00
• CPC Class Codes: H04L 69/22 Parsing or analysis of headers
• CPC Class Codes: H04L 69/325 in the network layer [OSI layer 3], e.g. X.25 H04L69/16 takes precedence
• CPC Class Codes: H04L 9/40 Network security protocols
• CPC Class Codes: Y10S 370/908 Local area network

Abstract

Method and apparatus by which an interactive network board can determine which of plural frame packet types is currently being used for LAN communication on a local area network. A prescanning software module simultaneously binds itself through a link support layer to each of the plural frame packet types and then deactivates itself. The LAN communication network is then monitored for broadcast traffic so as to capture a LAN frame packet, whereupon the link support layer provides data groups for the captured frame packet, each of the data groups corresponding to a different one of the plural frame packet types. The prescanner is reactivated so as to prescan each data group for a predetermined IPX header, and determines the frame packet type in correspondence to the data group having the predetermined IPX header. The prescanner is operative in a multiprotocol network environment in which two different LAN operating systems having respectively different operating protocols, such as Novell-compatible and UNIX-compatible operating systems, both carry on LAN communication on a single network bus. In this case, the prescanner repeats operations for each of the different operating protocols.

Claims

1. A method of determining which of plural predetermined frame formats is being used to exchange frame packets between LAN devices over a physical communications medium, the method comprising the following steps which are all performed in the same LAN device:

downloading a LAN communication module which includes a software protocol stack having a link support layer, the link support layer being configurable to bind to any of the plural predetermined frame formats;

automatically configuring the link support layer to bind simultaneously to all of the plural predetermined frame formats;

monitoring the LAN physical communications medium to capture broadcast traffic;

decoding the captured broadcast traffic into plural data groups, one data group being provided for each of the plural predetermined frame formats such that each data group corresponds to a respective one of the plural predetermined frame formats;

prescanning each data group for the presence of a predetermined header; and

storing a frame format that corresponds to the data group having the predetermined header.

2. The method according to claim 1, further comprising the step of executing a prescanning module for prescanning the plural data groups, the prescanning module configuring the link support layer to bind simultaneously to each of the plural frame formats.

3. The method according to claim 1, wherein said LAN physical communications medium comprises a LAN communication bus;

and

wherein said monitoring step monitors the LAN communication bus for broadcast traffic to any LAN destination.

4. The method according to claim 1, wherein, in said prescanning step, each data group is examined for internetwork packet exchange (IPX) header information.

5. A method according to claim 1, further comprising the steps of:

configuring the link support layer to bind to frame packets having the format stored in said storing step; and

effecting communication between the LAN devices over the LAN physical communications medium using the frame packets having the format stored in said storing step.

6. The method according to claim 2, wherein said prescanning module simultaneously binds the link support layer to each of the plural frame formats.

7. The method according to claim 6, wherein the frame formats are selected from the group consisting of Ethernet_-- 802.3, Ethernet_-- II, Ethernet_-- 802.3 and Ethernet_-- SNAP.

8. A method by which an interactive network board can determine which of plural frame formats is being used to exchange frame packets between LAN devices over a physical communications medium of a LAN, the interactive network board having a software protocol stacker configurable to use any of the plural frame formats, comprising the steps of:

downloading a prescanning software module from a ROM on the interactive network board to a first area of a RAM on the interactive network board, and initiating execution of the prescanning software module out of the RAM;

configuring a link support layer on the software protocol stack of the interactive network board using the prescanning software module to bind simultaneously to each of the plural frame formats;

deactivating the prescanning software module;

monitoring communication over the LAN physical communications medium for broadcast traffic so as to capture a LAN frame packet;

decoding the captured LAN frame packet into plural data groups, one data group being provided for each of the plural frame formats such that each data group corresponds to a respective one of the plural frame formats;

reactivating the prescanning software module so as to prescan each data group for a predetermined internetwork packet exchange (IPX) header; and

storing a frame format that corresponds to the data group having the predetermined IPX header.

9. The method according to claim 8, further comprising the step of freeing the first area in the RAM so as to permit overwriting of the prescanning software module.

10. The method according to claim 8, further comprising the step of downloading an internetwork packet exchange (IPX) network communication program from the ROM into the RAM and configuring the IPX network communication program to bind to the stored frame format.

11. A method according to claim 8, further comprising the steps of:

configuring the link support layer to bind to frame packets having the format stored in said storing step; and

effecting communication over the LAN physical communications medium using the frame packets having the format stored in said storing step.

12. Apparatus for adaptively determining which of plural predetermined frame formats is being used to exchange frame packets between LAN devices over a physical communications medium of a local area network (LAN), comprising:

an interactive network board for interfacing between a peripheral and the LAN, said interactive network board being connectable to the peripheral via a peripheral interface, and being connectable to the LAN via a LAN interface, the interactive network board having a software protocol stack which is configurable to use any of the plural predetermined frame formats;

a processing unit, disposed on said board, for executing stored program instruction process steps; and

a memory on said board for storing process steps for execution by said processing unit, said memory including process steps to download the software protocol stack from said memory to a RAM on the interactive network board and thereafter to initiate execution of the software protocol stack, to automatically configure a link support layer in the software protocol stack of the interactive network board to bind simultaneously to all predetermined frame formats, to monitor the LAN physical communications medium, to capture a frame packet on the LAN physical communications medium, to prescan the captured frame packet to determine which one of the plural predetermined frame formats is used in the captured frame packet, and to store the frame format used in the captured frame packet.

13. The apparatus according to claim 12, wherein said memory stores process steps to prescan the captured frame packet for the presence of a predetermined header.

14. An apparatus according to claim 12, wherein said memory further stores process steps to configure the link support layer to bind to frame packets having the format stored in the storing step, and to effect communication over the LAN physical communications medium using the frame packets having the format stored in said storing step.

15. The apparatus according to claim 13, wherein said memory stores process steps to execute the link support layer to the network interface, and process steps to bind the link support layer simultaneously to each of the plural predetermined frame formats.

16. The apparatus according to claim 15, wherein said memory further stores process steps for executing an internetwork packet exchange ("IPX") module and wherein said predetermined header is comprised by IPX information.

17. The apparatus according to claim 16, wherein said processing unit configures the IPX module to bind to the stored frame format.

18. A LAN device for adaptively determining which of plural predetermined frame formats is being used to exchange frame packets between other LAN devices over a physical communications medium of a LAN, comprising:

a local area network (LAN) interface for interfacing to the LAN physical communications medium;

a downloadable LAN communication module which includes a software protocol stack having a link support layer ("LSL"), the LSL being configurable to bind to any of the plural predetermined frame formats, the LSL being automatically configured to bind simultaneously to all of the plural predetermined frame formats, the LSL for supporting linkage with said LAN interface by decoding captured broadcast traffic into plural data groups, one data group being provided for each of the plural predetermined frame formats such that each data group corresponds to a respective one of the plural predetermined frame formats;

a memory for storing a frame format; and

a prescanner for monitoring the LAN physical communications medium to capture LAN broadcast traffic, for simultaneously binding said LSL to each of the plural predetermined frame formats, for receiving data groups from said LSL for a captured frame packet, each of the data groups corresponding to a respective one of the plural predetermined frame formats, for scanning received data groups for the presence of a predetermined header, and for storing a frame format in said memory which corresponds to the data group having the predetermined header.

19. The apparatus according to claim 18, further comprising an internetwork packet exchange ("IPX") module, wherein the predetermined header is comprised by IPX header information.

20. The apparatus according to claim 19, wherein the IPX module binds to the frame format stored in said memory.

21. A method of determining which of plural predetermined frame formats is being used by each of different software protocol stacks to exchange frame packets between LAN devices, comprising the following steps which are performed in the same LAN device:

a first downloading step of downloading a LAN communication module which includes a software protocol stack having a link support layer, the link support layer being configurable to bind to any of the plural predetermined frame formats;

a first configuring step of automatically configuring the link support layer to bind simultaneously to all of the plural predetermined frame formats;

a first monitoring step of monitoring a LAN physical communications medium to capture first protocol broadcast traffic;

a first decoding step of decoding the captured first protocol broadcast traffic into plural data groups, one data group being provided for each of the plural predetermined frame formats such that each data group corresponds to a respective one of the plural predetermined frame formats;

a first prescanning step of prescanning each data group for the presence of a predetermined header;

a first storing step of storing a first protocol frame format which corresponds to a data group having the predetermined header;

a second downloading step of downloading a LAN communication module which includes a software protocol stack having a link support layer, the link support layer being configurable to bind to any of the plural predetermined frame formats;

a second configuring step of automatically configuring the link support layer to bind simultaneously to all of the plural predetermined frame formats;

a second monitoring step of monitoring the LAN physical communications medium to capture second protocol broadcast traffic;

a second decoding step of decoding the captured second protocol broadcast traffic into plural data groups, one data group being provided for each of the plural predetermined frame formats such that each of the data groups corresponds to a respective one of the plural predetermined frame formats;

a second prescanning step of prescanning each data group for the presence of a predetermined header; and

a second storing step of storing a second protocol frame format which corresponds to the data group having the predetermined header.

22. The method according to claim 21, further comprising the step of executing a prescanning module for prescanning of the data groups, the prescanning module configuring the link support layer to bind simultaneously to each of the plural predetermined frame formats.

23. The method according to claim 21, wherein said first and second monitoring steps monitor the LAN physical communications medium for broadcast traffic to any LAN destination.

24. The method according to claim 21, wherein the first protocol includes Novell-compatible protocol and wherein, in said first prescanning step, each data group is examined for internetwork packet exchange (IPX) header information.

25. The method according to claim 21, wherein the second protocol includes UNIX-compatible protocol and wherein, in said second prescanning step, each data group is examined for TCP/IP header information.

26. The method according to claim 22, wherein said prescanning module simultaneously binds the link support layer to each of plural frame formats.

27. The method according to claim 26, wherein the frame formats are selected from the group consisting of Ethernet_-- 802.2, Ethernet_-- II, Ethernet_-- 802.3 and Ethernet_-- SNAP.

28. A method by which an interactive network board can determine which of plural frame formats is being used by different software protocol stacks to exchange frame packets over a physical communications medium of a local area network (LAN), comprising the steps of:

downloading a prescanning software module from ROM on the interactive network board to a first area of RAM on the interactive network board and initiating execution of the prescanning software module out of RAM;

a first binding step for configuring a link support layer on one software protocol stack using the prescanning software module to bind simultaneously to each of plural first protocol frame formats;

a first deactivating step for deactivating the prescanning software module;

a first monitoring step for monitoring the LAN physical communications medium in the LAN communication network for broadcast traffic so as to capture a first protocol frame packet;

a first decoding step for decoding the captured first protocol frame packet into plural data groups, one data group being provided for each of the plural first protocol frame formats such that each data group corresponds to a respective one of the plural first protocol frame formats;

a first reactivating step for reactivating the prescanning software module so as to prescan each data group for a predetermined first protocol header;

a first storing step for storing a frame format that corresponds to the data group having the predetermined first protocol header;

a second binding step for configuring a link support layer on one software protocol stack using the prescanning software module to bind simultaneously to each of plural second protocol frame formats;

a second deactivating step for deactivating the prescanning software module;

a second monitoring step for monitoring the LAN physical communications medium for broadcast traffic so as to capture a second protocol frame packet;

a second decoding step for decoding the captured second protocol frame packet into plural data groups, one data group being provided for each of the second protocol frame formats such that each of the plural data groups corresponds to a respective one of the plural second protocol frame formats;

a second reactivating step for reactivating the prescanning software module so as to prescan each data group for a predetermined second protocol header; and

a second storing step for storing a frame format that corresponds to the data group having the predetermined second protocol header.

29. The method according to claim 28, wherein the first network operating system includes a Novell-compatible operating system, and wherein said first reactivating step prescans each data group for the presence of a predetermined internetwork packet exchange (IPX) header.

30. The method according to claim 28, wherein the second network operating system includes a UNIX-compatible operating system, and wherein said second reactivating step prescans each data group for the presence of a predetermined TCP/IP header.

31. The method according to claim 29, further comprising the step of downloading an IPX network communication program from the ROM into the RAM and configuring the IPX network communication program to bind to the frame format stored in said first storing step.

32. The method according to claim 30, further comprising the step of downloading a TCP/IP network communication program from the ROM into the RAM and configuring the TCP/IP network communication program to bind to the frame format stored in said second storing step.

33. Computer-executable process steps stored on a computer-readable medium, the process steps to determine which of plural predetermined frame formats is being used to exchange frame packets between LAN devices over a physical communications medium, the method comprising the following steps which are all performed in the same LAN device:

a downloading step to download a LAN communication module which includes a software protocol stack having a link support layer, the link support layer being configurable to bind to any of the plural predetermined frame formats;

a configuring step to automatically configure the link support layer to bind simultaneously to all of the plural predetermined frame formats;

a monitoring step to monitor the LAN physical communications medium to capture broadcast traffic;

a decoding step to decode the captured broadcast traffic into plural data groups, one data group being provided for each of the plural predetermined frame formats such that each data group corresponds to a respective one of the plural predetermined frame formats;

a prescanning step to prescan each data group for the presence of a predetermined header; and

a storing step to store a frame format that corresponds to the data group having the predetermined header.

34. Computer-executable process steps stored on a computer-readable medium, the process steps adaptively to determine which of plural predetermined frame formats is being used to exchange frame packets between LAN devices over a physical communications medium of a local area network (LAN), comprising:

a downloading step to download a software protocol stack from a memory on the interactive network board to a RAM on the interactive network board and thereafter to initiate execution of the software protocol stack;

a configuring step to automatically configure a link support layer in the software protocol stack of the interactive network board to bind simultaneously to all predetermined frame formats;

a monitoring step to monitor the LAN physical communications medium;

a capturing step to capture a frame packet on the LAN physical communications medium;

a prescanning step to prescan the captured frame packet to determine which one of the plural predetermined frame formats is used in the captured frame packet; and

a storing step to store the frame format used in the captured frame packet in a memory on the interactive network board.

35. Computer-executable process steps stored on a computer-readable medium, the process steps to adaptively determine which of plural predetermined frame formats is being used to exchange frame packets between LAN devices over a physical communications medium of a LAN, comprising:

a downloading step to download, to a RAM on a LAN device, a LAN communication module which includes a software protocol stack having a link support layer ("LSL"), the LSL being configurable to bind to any of the plural predetermined frame formats, the LSL being automatically configured to bind simultaneously to all of the plural predetermined frame formats, the LSL for supporting linkage with a LAN interface by decoding captured broadcast traffic into plural data groups, one data group being provided for each of the plural predetermined frame formats such that each data group corresponds to a respective one of the plural predetermined frame formats;

a monitoring step to monitor the LAN physical communications medium to capture LAN broadcast traffic;

a binding step to simultaneously bind the LSL to each of the plural predetermined frame formats;

a receiving step to receive data groups from the LSL for a captured frame packet, each of the data groups corresponding to a respective one of the plural predetermined frame formats;

a scanning step to scan received data groups for the presence of a predetermined header; and

a storing step to store a frame format in the memory which corresponds to the data group having the predetermined header.

36. Computer-executable process steps stored on a computer-readable medium, the process steps to determine which of plural predetermined frame formats is being used by each of different software protocol stacks to exchange frame packets between LAN devices, comprising the following steps which are performed in the same LAN device:

a first downloading step to download a LAN communication module which includes a software protocol stack having a link support layer, the link support layer being configurable to bind to any of the plural predetermined frame formats;

a first configuring step to automatically configure the link support layer to bind simultaneously to all of the plural predetermined frame formats;

a first monitoring step to monitor a LAN physical communications medium to capture first protocol broadcast traffic;

a first decoding step to decode the captured first protocol broadcast traffic into plural data groups, one data group being provided for each of the plural predetermined frame formats such that each data group corresponds to a respective one of the plural predetermined frame formats;

a first prescanning step to prescan each data group for the presence of a predetermined header;

a first storing step to store a first protocol frame format which corresponds to a data group having the predetermined header;

a second downloading step to download a LAN communication module which includes a software protocol stack having a link support layer, the link support layer being configurable to bind to any of the plural predetermined frame formats;

a second configuring step to automatically configure the link support layer to bind simultaneously to all of the plural predetermined frame formats;

a second monitoring step to monitor the LAN physical communications medium to capture second protocol broadcast traffic;

a second decoding step to decode the captured second protocol broadcast traffic into plural data groups, one data group being provided for each of the plural predetermined frame formats such that each of the data groups corresponds to a respective one of the plural predetermined frame formats;

a second prescanning step to prescan each data group for the presence of a predetermined header; and

a second storing step to store a second protocol frame format which corresponds to the data group having the predetermined header.

37. Computer-executable process steps stored on a computer-readable medium, the process steps being used in an interactive network board to determine which of plural frame formats is being used to exchange frame packets between LAN devices over a physical communications medium of a LAN, the interactive network board having a software protocol stack configurable to use any of the plural frame formats, comprising:

a downloading step to download a prescanning software module from a ROM on the interactive network board to a first area of a RAM on the interactive network board, and to initiate execution of the prescanning software module out of the RAM;

a configuring step to configure a link support layer on the software protocol stack of the interactive network board using the prescanning software module to bind simultaneously to each of the plural frame formats;

a deactivating step to deactivate the prescanning software module;

a monitoring step to monitor communication over the LAN physical communications medium for broadcast traffic so as to capture a LAN frame packet;

a decoding step to decode the captured LAN frame packet into plural data groups, one data group being provided for each of the plural frame formats such that each data group corresponds to a respective one of the plural frame formats;

a reactivating step to reactivate the prescanning software module so as to prescan each data group for a predetermined internetwork packet exchange (IPX) header; and

a storing step to store a frame format that corresponds to the data group having the predetermined IPX header.

38. Computer-executable process steps stored on a computer-readable medium, the process steps being used in an interactive network board to determine which of plural frame formats is being used by different software protocol stacks to exchange frame packets over a physical communications medium of a local area network (LAN), comprising:

a downloading step to download a prescanning software module from ROM on the interactive network board to a first area of RAM on the interactive network board and to initiate execution of the prescanning software module out of RAM;

a first binding step to configure a link support layer on one software protocol stack using the prescanning software module to bind simultaneously to each of plural first protocol frame formats;

a first deactivating step to deactivate the prescanning software module;

a first monitoring step to monitor the LAN physical communications medium in the LAN communication network for broadcast traffic so as to capture a first protocol frame packet;

a first decoding step to decode the captured first protocol frame packet into plural data groups, one data group being provided for each of the plural first protocol frame formats such that each data group corresponds to a respective one of the plural first protocol frame formats;

a first reactivating step to reactivate the prescanning software module so as to prescan each data group for a predetermined first protocol header;

a first storing step to store a frame format that corresponds to the data group having the predetermined first protocol header;

a second binding step to configure a link support layer on one software protocol stack using the prescanning software module to bind simultaneously to each of plural second protocol frame formats;

a second deactivating step to deactivate the prescanning software module;

a second monitoring step to monitor the LAN physical communications medium for broadcast traffic so as to capture a second protocol frame packet;

a second decoding step to decode the captured second protocol frame packet into plural data groups, one data group being provided for each of the second protocol frame formats such that each of the plural data groups corresponds to a respective one of the plural second protocol frame formats;

a second reactivating step to reactivate the prescanning software module so as to prescan each data group for a predetermined second protocol header; and

a second storing step to store a frame format that corresponds to the data group having the predetermined second protocol header.