Service-function chaining using extended service-function chain proxy for service-function offload

An apparatus comprising:

• a network interface unit to send and receive packets to and from a network;
• and
• a processor of a network node configured to connect to a bi-directional service path hosting a chain of service-functions that are applied to packets traversing the service path, wherein the packets each includes a service header having a service path identifier and a service index, wherein the processor is configured to perform operations including:
• receiving a packet of a traffic flow traversing the service path in a forward direction of the service path toward a service-function classifier operably connected to an end of the service path;
• determining whether network address translation by one of the service-functions changed a flow tuple of the packet identifying the traffic flow;
• when the network address translation changed the flow tuple, determining whether to update the service-function classifier with the flow tuple;
• and
• when it is determined to update, updating the service-function classifier by sending to the service-function classifier, via a communications channel, an update message including the flow tuple and the service path identifier to enable classification of a flow for the service path in a reverse direction.

A non-transitory computer readable storage medium encoded with instructions that, when executed by a processor of a network node connected to a bi-directional service path hosting a chain of service-functions that are applied to packets traversing the service path, wherein the packets each includes a service header having a service path identifier and a service index, cause the processor to perform operations including:

• receiving a packet of a traffic flow traversing the service path in a forward direction of the service path toward a service-function classifier operably connected to an end of the service path;
• determining whether network address translation by one of the service-functions changed a flow tuple of the packet identifying the traffic flow;
• when the network address translation changed the flow tuple, determining whether to update the service-function classifier with the flow tuple;
• and
• when it is determined to update, updating the service-function classifier by sending to the service-function classifier, via a communications channel, an update message including the flow tuple and the service path identifier to enable classification of a flow for the service path in a reverse direction.