Segment Routing for Chaining Micro-Services at Different Programmable Network Levels

Network Function Virtualization (NFV) is now well known for making network services deployable in a virtual environment, for instance in data-centers. On another hand, the programability of functions has come down to the network forwarding equipment itself, such as programmable switches, using the Programming Protocol-independent Packet Processors (P4) solution. Each of the two programmable concepts has its own advantages and drawbacks and micro-services should be preferably developed in one or the other solution depending on their constraints and requirements. In this paper, our objective is to combine both approaches. We propose to leverage Segment Routing (SR) to define a solution allowing to chain the micro-services to be executed at both levels. This signaling protocol is integrated within network equipment but not within a NFV infrastructure. To overcome it, we design an intermediary proxy between the P4 nodes and the VNFs. This proxy is in charge of managing the SR labels and their association with the related VNF. The demonstrator we have developed proves the feasibility of the approach and opens the way towards a composition of network services taking the best of the two levels of programmable networks.