Modifying backbone service instance identifiers based on an identified flow of associated frames

Patent metadata

Field	Value
Publication number	US-9553737-B2
Application number	US-201113294164-A
Country	US
Kind code	B2
Filing date	Nov 10, 2011
Priority date	Nov 10, 2011
Publication date	Jan 24, 2017
Grant date	Jan 24, 2017

Abstract

In one embodiment, backbone service instance identifiers (I-SIDs) of backbone frames are modified based on flow identification of frames encapsulated therein to induce entropy into the headers of the backbone frames. Backbone packet switching devices use the modified service instance identifier to load balance the corresponding frame through the backbone network. At an exit point of the backbone network, the original backbone service instance identifier (I-SID) associated with a frame encapsulated in a backbone frame is recovered from the modified service instance identifier, with this recovery typically including determining the flow identification of the frame encapsulated in the backbone frame.

First claim

What is claimed is:

1. A method, comprising:
determining a flow identification value derived from one or more fields of the header of a particular frame;
generating a modulated service instance identifier, which includes modulating a backbone service instance identifier (I-SID) associated with the particular frame with the flow identification value, with said modulating including performing a function with operands of the backbone service instance identifier (I-SID) and the flow identification value resulting in the modulated service instance identifier with the backbone service instance identifier (I-SID) being recoverable from the modulated service instance identifier and the flow identification value; and
sending, from a first packet switching device into a network, a backbone frame encapsulating the particular frame, with the header of the backbone frame including the modulated service instance identifier;
receiving, at a particular packet switching device, the backbone frame;
processing, at the particular packet switching device, the modulated service instance identifier to generate the backbone service instance identifier (I-SID), with said processing the modulated service instance identifier including determining the flow identification value from said one or more fields of the header of the particular frame and demodulating the backbone service instance identifier (I-SID) from the modulated service instance identifier based on the flow identification value, with said demodulating the backbone service instance identifier (I-SID) from the modulated service instance identifier based on the flow identification value including performing an exclusive-OR operation on the modulated service instance identifier and the flow identification value; and
sending the particular frame from the particular packet switching device based on the backbone service instance identifier (I-SID).

2. The method of claim 1 , comprising:
receiving, at the first packet switching device, the particular frame;
determining, at the first packet switching device, the backbone service instance identifier (I-SID) corresponding to the particular frame; and
encapsulating the particular frame to produce the backbone frame, with the header of the backbone frame including the modulated service instance identifier.

3. The method of claim 1 , comprising: a second packet switching device in the network communicating the backbone frame to a third packet switching device; wherein said communicating includes load balancing the backbone frame across a plurality of links based on using the modulated service instance identifier as a load balancing value.

4. The method of claim 1 , wherein said modulating the I-SID with the flow identification value to generate a modulated service instance identifier includes performing an exclusive-OR operation on the backbone service instance identifier (I-SID) and the flow identification value.

5. The method of claim 1 , wherein said determining the flow identification value derived from one or more fields of the header of the particular frame includes determining the flow identification value derived from at least two fields of the header of the particular frame; wherein said at least two fields of the header of the particular frame used in determining the flow identification value include both the source address and destination address of the particular frame.

6. A method, comprising:
determining a flow identification value derived from one or more fields of the header of a particular frame;
generating a modulated service instance identifier, which includes modulating a backbone service instance identifier (I-SID) associated with the particular frame with the flow identification value; and
sending, from a first packet switching device into a network, a backbone frame encapsulating the particular frame, with the header of the backbone frame including the modulated service instance identifier;
wherein said modulating the I-SID with the flow identification value to generate a modulated service instance identifier includes performing an exclusive-OR operation on the backbone service instance identifier (I-SID) and the flow identification value.

7. A method, comprising:
receiving, at a packet switching device, a backbone frame including a modulated service instance identifier and a particular frame;
processing the modulated service instance identifier to determine a backbone service instance identifier (I-SID) corresponding to the particular frame, wherein said processing the modulated service instance identifier includes: determining a flow identification value from at least two fields of the header of the particular frame, and demodulating the backbone service instance identifier (I-SID) from the modulated service instance identifier based on the flow identification value; and
sending the particular frame from the packet switching device based on the backbone service instance identifier (I-SID), or sending of a modified backbone frame based on said received backbone frame with the modified backbone frame including the backbone service instance identifier (I-SID) and the particular frame;
wherein said demodulating the backbone service instance identifier (I-SID) from the modulated service instance identifier based on the flow identification value includes performing an exclusive-OR operation on the modulated service instance identifier and the flow identification value.

8. A packet switching device, comprising:
a plurality of interfaces configured to send and receive packets;
memory; and
one or more processors perform operations, including:
determining a flow identification value derived from one or more fields of the header of a particular frame; and
generating a modulated service instance identifier, which includes modulating a backbone service instance identifier (I-SID) associated with the particular frame with the flow identification value, with said modulating including performing a function with operands of the backbone service instance identifier (I-SID) and the flow identification value resulting in the modulated service instance identifier with the backbone service instance identifier (I-SID) being recoverable from the modulated service instance identifier and the flow identification value;

wherein the packet switching device is configured to send a backbone frame encapsulating the particular frame, with the header of the backbone frame including the modulated service instance identifier;
wherein said modulating the I-SID with the flow identification value to generate a modulated service instance identifier includes performing an exclusive-OR operation on the backbone service instance identifier (I-SID) and the flow identification value.

9. The packet switching device of claim 8 , wherein said operations include:
determining the backbone service instance identifier (I-SID) corresponding to the particular frame received on one of the plurality of interfaces; and
encapsulating the particular frame to produce the backbone frame, with the header of the backbone frame including the modulated service instance identifier.

10. The packet switching device of claim 8 , wherein said determining the flow identification value derived from one or more fields of the header of the particular frame includes determining the flow identification value derived from at least two fields of the header of the particular frame; wherein said at least two fields of the header of the particular frame used in determining the flow identification value include both the source address and destination address of the particular frame.

11. A packet switching device, comprising:
a plurality of interfaces confi

Assignees

• Sajassi Ali
• Salam Samer M
• Cisco Tech Inc

Inventors

• Sajassi Ali
• Salam Samer M

Classifications

• H04L12/4662

  wherein a VLAN tag represents a service instance, e.g. I-SID in PBB · CPC title

• H04L12/462

  LAN interconnection over a bridge based backbone · CPC title

• H04L47/2483

  involving identification of individual flows · CPC title

• H04L47/24

  Traffic characterised by specific attributes, e.g. priority or QoS · CPC title

• H04L12/4633 Primary

  Interconnection of networks using encapsulation techniques, e.g. tunneling · CPC title