The existing Quantum API provides APIs for based L2 and L3 communication. There is a lot of demand for inserting higher-level services, for example, firewalling, load-balancing, VPN, etc.

The discussion will talk both about generic mechanisms for extending the L2/L3 model to insert services. We will not discuss the design of individual service APIs (LB, FW, etc.) other than as example of how one such service insertion mechanism might be better suited than another.

We will also talk about a mechanism by which third-parties can services APIs that are independent of whatever "core plugin" is running.