SESSION-AWARE SERVICE CHAINING WITHIN COMPUTER NETWORKS

摘要

Techniques are described for providing session-aware, stateful network services to subscriber packet flows. Devices within a service provider network direct subscriber packets along service chains. Each tunnel is established to direct traffic according a particular ordered set of network services for the corresponding service chain. An ingress device for the tunnels encapsulate the subscriber packets and embed opaque session cookies that each uniquely identifies a collection of packet flows of a subscriber session amongst other packet flows transported by a given service tunnel. Each service node need only identify the tunnel on which a tunnel packet was received and the session cookie embedded within the tunnel packet to uniquely associate the encapsulated subscriber packet with a subscriber session, without needing to further inspect the encapsulated subscriber packet, and to index or otherwise retrieve state and statistics required to enforce the network service the service nod is programmed to deliver.

主权项

1. A method comprising:
receiving, by a network device of an service provider network, a subscriber packet of a packet flow sourced by a subscriber device and destined to a packet data network; forming a tunnel packet by encapsulating the subscriber packet within a payload of the tunnel packet and constructing a header of the tunnel packet for transport by a tunnel associated with a service chain, wherein the service chain comprises an ordered set of one or more stateful services for application, by a set of service nodes, to a plurality of packet flows from a plurality of subscriber devices; embedding, within the tunnel packet, a session cookie storing a value that uniquely identifies a collection of packet flows sourced by the subscriber device; and forwarding, by the network device, the tunnel packet toward the service nodes.