Backup service function notification and synchronization

A method comprising:

• classifying, by a service function classifier, a packet of a packet flow to a service function chain;
• determining, by the service function classifier, one or more backup service functions for an active service function of the service function chain;
• encapsulating, by the classifier, the packet with a network service header,
• wherein the network service header includes backup service function information that identifies one or more computing devices that host the one or more backup service functions;
• and
• sending, by the classifier, the packet encapsulated with the network service header to a computing device that hosts the active service function in the service function chain to enable the computing device that hosts the active service function to send, based at least on the backup service function information, state information for a session of the active service function to the one or more computing devices that host the one or more backup service functions to enable the one or more backup service functions to assume stateful processing of packets of the packet flow.

A network system comprising:

• a plurality of service functions;
• and
• a computing device comprising a service function classifier configured to:
• classify a packet of a packet flow classified to a service function chain including the plurality of service functions;
• determine one or more backup service functions for an active service function of the service function chain;
• encapsulate the packet with a network service header, wherein the network service header includes backup service function information that identifies one or more computing devices that host the one or more backup service functions;
• and
• send the packet encapsulated with the network service header to a computing device that hosts the active service function in the service function chain to enable the computing device that hosts the active service function to send, based at least on the backup service function information, state information for a session of the active service function to the one or more computing devices that host the one or more backup service functions to enable the one or more backup service functions to assume stateful processing of packets of the packet flow.