Modified ethernet preamble for inter line card communications in a modular communication chassis

• US 9,509,810 B2
• Filed: 11/19/2015
• Issued: 11/29/2016
• Est. Priority Date: 09/25/2012
• Status: Active Grant

• Current Assignee: Accedian Networks Inc. (Cisco Systems, Inc.)
• Original Assignee: Accedian Networks Inc. (Cisco Systems, Inc.)
• Inventors: Viens, Yanick, Rochon, Steve
• Primary Examiner(s): Pham, Chi H
• Assistant Examiner(s): Boakye, Alexander O
• Application Number:
  US14/945,845
• Publication Number:
  US 20160072931A1
• Time in Patent Office: 376 Days
• Field of Search: 370/474, 370/445, 370/522, 370/523, 370/528, 370/465, 709/223, 709/236, 709/246, 709/249
• US Class Current: 1/1
• CPC Class Codes: H04L 12/2892 characterised by the access multiplexer architecture
• CPC Class Codes: H04L 12/462 LAN interconnection over a bridge based backbone
• CPC Class Codes: H04L 45/502 Frame based
• CPC Class Codes: H04L 45/74 Address processing for routing
• CPC Class Codes: H04L 49/351 for local area network [LAN], e.g. Ethernet switches
• CPC Class Codes: H04L 49/9057 Arrangements for supporting packet reassembly or resequencing
• CPC Class Codes: H04L 69/22 Parsing or analysis of headers
• CPC Class Codes: H04L 69/324 in the data link layer [OSI layer 2], e.g. HDLC

Abstract

A method of providing information regarding an Ethernet frame, within the Ethernet preamble of the Ethernet frame, comprises inserting into the Ethernet preamble an inter-line-card header that includes a start control character, a version number, a parity bit, a source port, a destination port, and a forwarding domain entry; and preserving said inter-line-card header, inside of said Ethernet preamble, in a Media Access Control (MAC) sub-layer in said Ethernet frame. The method may include a step of selecting the decoding format for the inter-line-card header corresponding to the version number and/or forwarding other Ethernet frames according to additional forwarding information provided by the forwarding domain entry. The inter-line-card header may be preserved in the MAC sub-layer by keeping the Ethernet preamble at the beginning of an Ethernet frame received over an Ethernet backplane, and passing the combined preamble and associated Ethernet frame to an inter-line-card header processing module.

Claims

1. A method of providing information regarding an Ethernet frame for transmission within a communication chassis with a plurality of line cards interconnected via an Ethernet backplane and via point to point links, said method comprising:

modifying, at one of said plurality of line cards, an Ethernet preamble of the Ethernet frame to include the information regarding the Ethernet frame, creating a modified Ethernet preamble;

preserving by a Media Access Control (MAC) sub-layer module said modified Ethernet preamble; and

transmitting said modified Ethernet frame to another one of said plurality of line cards located within said communication chassis.

2. The method of claim 1 wherein the information regarding the Ethernet frame comprises at least one of a start control character, a version number, a parity bit, a source port, a destination port, a forwarding domain entry, an action field, and an action parameter.

3. A method of efficiently transmitting an Ethernet frame between a plurality of line cards of a communication chassis, said method comprising:

modifying an Ethernet preamble of said Ethernet frame to include information associated with the Ethernet frame, creating a modified Ethernet preambleJoe Bassett <

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preserving by a Media Access Control (MAC) sub-layer module said modified Ethernet preamble; and

transmitting said modified Ethernet frame to another one of said plurality of line cards located within said communication chassis.

4. The method of claim 3 wherein the information associated with the Ethernet frame comprises at least one of a start control character, a version number, a parity bit, a source port, a destination port, a forwarding domain entry, an action field, and an action parameter.