Service Node Using Services Applied by an Application Node

摘要

Packets are encapsulated and sent from a service node to an application node for applying one or more Layer-4 to Layer-7 services to the packets, with service-applied packets being returned to the service node. An identification of a virtual private network (VPN) may be carried within a request packet, encapsulating a particular packet, sent by a service node to an application node for applying a service to the particular packet; with the corresponding response packet sent to the service node including an identification of the VPN for use by the service node in forwarding the services-applied packet. Additionally, parameters may be included in a request packet to identify a particular service of a general service to be applied to a particular packet encapsulated in the request packet.

主权项

1. A packet switching device, comprising:
one or more processing elements; memory; a plurality of interfaces configured to send and receive packets; and one or more packet switching mechanisms configured to packet switch packets among said interfaces; wherein the packet switching device is configured to perform operations, including: receiving on one of the plurality of interfaces a particular packet from another packet switching device; and in response to determining to apply a service to the particular packet by one or more application nodes located remotely from the packet switching device: creating a request packet encapsulating the particular packet, with the request packet including an identification of the general service to be applied to the particular packet by said one or more application nodes, and one or more service parameters for the general service defining a particular service of the general service, with the identification of the general service and said one or more service parameters said included in the request packet in fields not within the particular packet; forwarding the request packet to a particular application node of said one or more application nodes, wherein each of said one or more application nodes is external to the packet switching device; receiving on one of the plurality of interfaces from an external source, a response packet corresponding to said forwarded request packet, the response packet encapsulating a service-applied packet corresponding to the particular packet after at least the particular service has been applied to the particular packet, not to the request packet, by said one or more application nodes; extracting the service-applied packet from the response packet; and sending the service-applied packet or a packet derived from the service-applied packet from the packet switching device on one of the plurality of interfaces; wherein the packet switching device, said another packet switching device, and each of said one or more application nodes are different stand-alone appliances communicatively coupled via one or more networks.