Open tomkivlin opened 3 years ago
By principle, SFC definition is in orchestration, devOps and SDN controller domain, but it requires support at networking requirements, which is relevant to Anuket RA2 forum.
SFC can be visualized as Service function plane (consists of SFF, SFC, SF, SF proxy) over Service function overlay network, which is realized over Overlay /underlay network. In Overlay network, packets are routed based on networking principles as destination ip, next hop. However, in service overlay network, packets are routed based on policies unlike overlay network, again defined at Orchestrator level. This requires specific support at CNI in CNF environment to provide such specific routing mechanism. It means, we need to define or capture items, which will help realize SFC at CNF environment, are
SFC Architecture Functional Components:- SFC can be visualized as made of these components which makes SFC possible.
Call flow- A possible use case to create the SFC in container system shown as below. After creation of container ( or existing container ), SFC interface(s) is(are) created, identified by interface Id(s) and attached with the container. These interface IDs ae used to render SFP for given SFC. Once packets received on these SFP, policy driven packet steering performed to route packets to SF for processing.
A Service Function Path consists of: • a set of container interface ports, to define the sequence of service functions • a set of flow classifiers, to specify the classified traffic flows to enter the chain (– out of scope of RA2) If a service function has a pair of ports, the first port in the port-pair is the ingress port of the service function, and the second port is the egress port of the service function. The first port of the first port-pair is the head of the service chain. The second port of the last port-pair is the tail of the service chain. A bidirectional service chain would be composed of two unidirectional Port Chains.
For example, [{p1: p2}, {p3: p4}, {p5: p6}] represents:
In addition, SFP represented in CNF environment as -
Summary to RA2 relevance:- Relevance to RA2-
Out of scope of RA2 :- Note:- these are not exhaustive list.
Updating better diagrams -
Architecture-
Call Flow
SFP illustration
SFP Data Model
check if content there and if so cleanup
As per discussion here: https://github.com/cntt-n/CNTT/pull/2121#discussion_r555208828