Network protocol sensor

• US 5,613,096 A
• Filed: 11/04/1994
• Issued: 03/18/1997
• Est. Priority Date: 11/04/1994
• Status: Expired due to Term

• Current Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Original Assignee: Canon Information Systems Incorporated (Canon Inc.)
• Inventors: Danknick, Daniel A.
• Primary Examiner(s): Teska, Kevin J.
• Assistant Examiner(s): NGUYEN, TAN QUANG
• Application Number:
  US08/336,062
• Time in Patent Office: 865 Days
• Field of Search: 395/500, 395/650, 395/309, 395/310, 395/311, 395/831, 395/850, 395/857, 395/858, 370/94.1, 370/100.1, 370/105.1, 370/60, 370/856
• US Class Current: 709/236
• CPC Class Codes: H04L 49/90 Buffering arrangements
• CPC Class Codes: H04L 49/901 using storage descriptor, e.g. read or write pointers
• CPC Class Codes: H04L 49/9031 Wraparound memory, e.g. overrun or underrun detection
• CPC Class Codes: H04L 49/9057 Arrangements for supporting packet reassembly or resequencing
• CPC Class Codes: H04L 69/18 Multiprotocol handlers, e.g. single devices capable of handling multiple protocols
• CPC Class Codes: H04L 9/40 Network security protocols

Abstract

A method of determining which of plural protocols are active on a computerized local area network. Each of plural frame types are registered with a link support layer (LSL) which monitors network communications for broadcast frame packets. A frame packet which matches a first one of the frame types is provided from LSL, and protocol header information in the received frame packet is decoded so as to determine protocol used in the frame packet. The first frame type is de-registered from LSL, a first protocol stack corresponding to the determined protocol is initialized using the first frame type, the first protocol stack is loaded, and the first protocol stack registers itself with LSL so that the first protocol stack receives future frame packets which match the first frame type. Thereafter, if LSL encounters any other frame types, the above processing is repeated so as to load and register any other needed protocol stacks.

Claims

1. A method of registering each of plural different protocol stacks with a link support layer (LSL) on a network, comprising the steps of:

executing the LSL so as to monitor network communications for broadcast frame packets, LSL being adapted to accept registrations for any one of plural frame types;

registering each of the plural frame types with LSL;

receiving from LSL a frame packet which matches a first one of the frame types;

decoding header information in the received frame packet so as to determine which protocol is used by the frame packet;

de-registering the first frame type from LSL, said step of de-registering not being performed in a case where the first frame type is an allowable frame type for a protocol stack not already registered with LSL;

initializing a first protocol stack corresponding to the determined protocol by using the first frame type;

loading the first protocol stack; and

registering the first protocol stack with LSL so that the first protocol stack receives future frame packets which match the first frame type.

2. A method according to claim 1, further comprising the step of executing the first protocol stack so as to broadcast network communications.

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

receiving from LSL a frame packet which matches a second one of the frame types;

decoding header information in the received frame packet so as to determine which protocol is used by the frame packet;

de-registering the second frame type from LSL;

initializing a second protocol stack corresponding to the determined protocol by using the second frame type;

loading the second protocol stack; and

registering the second protocol stack with LSL so that the second protocol stack receives future frame packets which match the second frame type.

4. A method according to claim 3, further comprising the steps of checking the first frame type against the second frame type and signalling an error in a case where said decoding step indicates that decoded header information in a second-received frame packet corresponds to the first protocol stack.

5. A networkable device in which each of plural different protocol stacks communicate on a network via a common link support layer (LSL), comprising:

a memory for storing process steps, the process steps including process steps comprising said LSL and process steps comprising said plural different protocol stacks;

a processor for executing the process steps stored in said memory;

wherein the process steps further include process steps to register each of said plural different protocol stacks with said LSL by (a) executing the LSL so as to monitor network communications for broadcast frame packets, LSL being adapted to accept registrations for any one of plural frame types, (b) registering each of the plural frame types with LSL, (c) receiving from LSL a frame packet which matches a first one of the frame types, (d) decoding header information in the received frame packet so as to determine which protocol is used by the frame packet, (e) de-registering the first frame type from LSL, said step of de-registering not being performed in a case where the first frame type is an allowable frame type for a protocol stack not already registered with LSL, (f) initializing a first protocol stack corresponding to the determined protocol by using the first frame type, (g) loading the first protocol stack, and (h) registering the first protocol stack with LSL so that the first protocol stack receives future frame packets which match the first frame type.

6. A device according to claim 5, further comprising process steps to execute the first protocol stack so as to broadcast network communications.

7. A device according to claim 5, further comprising process steps to:

receive from LSL a frame packet which matches a second one of the frame types;

decode header information in the received frame packet so as to determine which protocol is used by the frame packet;

de-register the second frame type from LSL;

initialize a second protocol stack corresponding to the determined protocol by using the second frame type;

load the second protocol stack; and

register the second protocol stack with LSL so that the second protocol stack receives future frame packets which match the second frame type.

8. A device according to claim 7, further comprising process steps to check the first frame type against the second frame type and signal an error in a case where said step to decode indicates that decoded header information in a second-received frame packet corresponds to the first protocol stack.

9. Computer executable process steps stored on a computer readable medium, said process steps for registering each of plural different protocol stacks with a link support layer (LSL), said process steps comprising:

an executing step to execute the LSL so as to monitor network communications for broadcast frame packets, LSL being adapted to accept registrations for any one of plural frame types;

a registering step to register each of the plural frame types with LSL;

a receiving step to receive from LSL a frame packet which matches a first one of the frame types;

a decoding step to decode header information in the received frame packet so as to determine which protocol is used by the frame packet;

a de-registering step to de-register the first frame type from LSL, said de-registering step not being performed in a case where the first frame type is an allowable frame type for a protocol stack not already registered with LSL;

an initializing step to initialize a first protocol stack corresponding to the determined protocol by using the first frame type;

a loading step to load the first protocol stack; and

a registering step to register the first protocol stack with LSL so that the first protocol stack receives future frame packets which match the first frame type.

10. Computer executable process steps according to claim 9, further comprising an executing step to execute the first protocol stack so as to broadcast network communications.

11. Computer executable process steps according to claim 9, further comprising:

a receiving step to receive from LSL a frame packet which matches a second one of the frame types;

a decoding step to decode header information in the received frame packet so as to determine which protocol is used by the frame packet;

a de-registering step to de-register the second frame type from LSL;

an initializing step to initialize a second protocol stack corresponding to the determined protocol by using the second frame type;

a loading step to load the second protocol stack; and

a registering step to register the second protocol stack with LSL so that the second protocol stack receives future frame packets which match the second frame type.

12. Computer executable process steps according to claim 11, further comprising a checking step to check the first frame type against the second frame type and signal an error in a case where said decoding step indicates that decoded header information in a second-received frame packet corresponds to the first protocol stack.