Segment Routing in Datacenter

Segment Routing is a network technology that proposes to solve many of the limitations of traditional IP & MPLS networks. It's proposes to be the bridge between th …

Segment Routing is a network technology that proposes to solve many of the limitations of traditional IP & MPLS networks. It’s proposes to be the bridge between the distributed intelligence of the currently deployed IP/MPLS networking protocols and the centralized optimization & programmability of the Software-Defined Networking. It enables a network to route a packet through a specific forwarding path based on the requirements of an application using the network for communication. This source routing paradigm of Segment Routing has many use cases in all areas of networking including the Massive Scalable Data Center ( MSDC ). Currently the MSDC has many problems which can be solved by Segment Routing - some of these are : 1. Per-packet/per-flowlet ECMP routing (vis-à-vis traditional per flow ECMP routing – “elephant & mouse flows” problem) 2. Performance-aware routing and dynamic fault avoidance (vis-à-vis network-imabalnce-oblivious ECMP SPF – prominent during failures) 3. Path visibility (“white-box view” vs “black-box view” of network) 4. Non-deterministic network probing. These can be solved using Segment Routing extensions with BGP in MSDC. The individual prefixes can be advertised via prefix-SIDs. A special prefix SID is the node-SID which identifies the originating node itself. The traffic engineering ( called Egress Peer Engineering ( EPE ) ) in node, link/adjacency and in a peer-group level can be achieved via the Peer-node/adj/set segments. All these dynamically distributed data points can be synced with a centralized controller using BGP Link State extensions.