Symmetric service chain binding

Patent metadata

Field	Value
Publication number	US-9258243-B2
Application number	US-201313891247-A
Country	US
Kind code	B2
Filing date	May 10, 2013
Priority date	May 10, 2013
Publication date	Feb 9, 2016
Grant date	Feb 9, 2016

Abstract

A plurality of network nodes are deployed in a network, each network node configured to apply a service function to traffic that passes through the respective network nodes. A controller generates information for a service chain that involves application to traffic of one or more service functions at corresponding ones of the plurality of network nodes along a forward path through the one or more network nodes. The controller identifies one or more of the service functions within the service chain that is stateful. When one or more of the service functions of the service chain is stateful, the controller generates information for a reverse path through the one or more service nodes for the one or more stateful service functions. The controller binds a forward chain identifier for the forward path with a reverse chain identifier for the reverse path for the service chain.

First claim

What is claimed is:

1. A method comprising:
in a network comprising a plurality of network nodes each configured to apply a service function to traffic that passes through the respective network nodes, a controller generating information for a first service chain that involves application to traffic of one or more service functions at corresponding ones of the plurality of network nodes along a forward path through the one or more network nodes, wherein the generated information for the first service chain including a forward chain identifier that identifies all service functions and their respective locations along the forward path;
identifying one or more of the service functions within the first service chain that are stateful and require flow state information be maintained such that forward traffic flows and reverse traffic flows be forwarded through same functions at same locations;
when one or more of the service functions of the first service chain are stateful and require flow state information be maintained such that forward traffic flows and reverse traffic flows be forwarded through same functions at same locations, generating information for a second service chain through the one or more network nodes for the one or more stateful service functions in a reverse path, wherein the generated information for the second service chain including a reverse chain identifier that identifies all service functions and their respective locations along the reverse path; and
binding the forward chain identifier for the first service chain with the reverse chain identifier for the second service chain.

2. The method of claim 1 , further comprising generating a service chain association for the first service chain and the second service chain, the service chain association comprising the forward chain identifier and the reverse chain identifier, wherein the forward chain identifier specifies an identifier of the network node and service function to be performed for each of the one or more service functions and classification criteria for traffic of the first service chain, and the reverse chain identifier specifies an identifier of the network node and service function for each stateful service function and classification criteria for traffic of the second service chain.

3. The method of claim 2 , further comprising sending the forward chain identifier to the one or more network nodes in the forward path and sending the reverse chain identifier to the one or more network nodes in the reverse path.

4. The method of claim 3 , further comprising generating a service header that represents a summarized view of the first service chain and the second service chain and generating the classification criteria of the first service chain and the second service chain, wherein sending comprises sending the service header and the classification criteria for the first service chain and the second service chain to the one or more network nodes.

5. The method of claim 4 , wherein sending further comprises sending the service header and the classification criteria for the first service chain and the second service chain to a head-end node in order to configure the head-end node to classify traffic in accordance with the classification criteria contained in the forward chain identifier so as to direct traffic matching the classification criteria into the forward path of the first service chain and to cause any network nodes at which traffic for the reverse path appears to intercept that traffic for the reverse path and direct it to the one or more service nodes of the reverse path of the second service chain in correct order.

6. The method of claim 5 , wherein sending comprises sending the service header for the first service chain and the second service chain so as to cause each network node within the first service chain and the second service chain to impose policy for an associated service function and to forward traffic, after application of the associated service function, to the next hop in the first service chain and the second service chain.

7. The method of claim 1 , further comprising receiving notifications of all active service functions among the plurality of network nodes, each notification including information describing service function capabilities.

8. The method of claim 7 , further comprising storing data describing attributes of all active service functions, wherein generating information for the first service chain comprises selecting necessary service functions and their associated network nodes for the first service chain from the stored data, and wherein identifying is based on the stored data.

9. An apparatus comprising:
a network interface unit configured to enable communications over a network, the network comprising a plurality of network nodes each configured to apply a service function to traffic that passes through the respective network nodes;
memory; and
a processor coupled to the network interface unit and the memory, wherein the processor is configured to:
generate information for a first service chain that involves application to traffic of one or more service functions at corresponding ones of the plurality of network nodes along a forward path through the one or more network nodes, wherein the generated information for the first service chain including a forward chain identifier that identifies all service functions and their respective locations along the forward path;
identify one or more of the service functions within the first service chain that are stateful and require flow state information be maintained such that forward traffic flows and reverse traffic flows be forwarded through same functions at same locations;
when one or more of the service functions of the first service chain are stateful and require flow state information be maintained such that forward traffic flows and reverse traffic flows be forwarded through same functions at same locations, generate information for a second service chain through the one or more network nodes for the one or more stateful service functions in a reverse path, wherein the generated information for the second service chain including a reverse chain identifier that identifies all service functions and their respective locations along the reverse path; and
generate information to bind the forward chain identifier for the first service chain with the reverse chain identifier for the second service chain.

10. The apparatus of claim 9 , wherein the processor is further configured to generate a service chain association for the first service chain and the second service chain, the service chain association comprising the forward chain identifier and the reverse chain identifier, wherein the forward chain identifier specifies an identifier of the network node and service function to be performed for each of the one or more service functions and classification criteria for traffic of the first service chain, and the reverse chain identifier specifies an identifier of the network node and service function for each stateful service function and classification criteria for traffic of the second service chain.

11. The apparatus of claim 10 , wherein the processor is configured to send, via the network interface unit, the forward chain identifier to the one or more network nodes in the forward path and to send the reverse chain identifier to the one or more network nodes in the reverse path.

12. The apparatus of claim 11 , wherein the processor is further configured to generate a service header that represents a summarized view of the first service chain and the second service chain and to generate the classification criteria of the

Assignees

• Cisco Tech Inc

Inventors

• Guichard James
• Quinn Paul
• Fernando Rex
• Sharma Govind P
• Ward David
• Bosch Hendrikus G P
• Fang Luyuan

Classifications

• H04L47/2441

  relying on flow classification, e.g. using integrated services [IntServ] · CPC title

• H04L47/2475 Primary

  for supporting traffic characterised by the type of applications · CPC title