Declarative and Expressive Approach to Control Forwarding Paths in Carrier Grade Networks

SDN 41

http://conferences.sigcomm.org/sigcomm/2015/pdf/papers/p15.pdf

Theory of computation: Constraint and logic programming
Network management: Routing protocols

Traffic engineering algorithms

ABSTRACT SDN simplifies network management by relying on declarativity (high-level interface) and expressiveness (network flexibility). We propose a solution to support those features while preserving high robustness and scalability as needed in carrier-grade networks.

Our solution: (i) a two-layer architecture separating connectivity and optimization tasks; and (ii) a centralized optimizer called DEFO, which translates high-level goals expressed almost in natural language into com- pliant network configurations.

DEFO improves the state of the art:

achieving better trade-offs for classic goals

supporting a larger set of goals (refined traffic engineering and service chaining)

optimizing large ISP networks in few seconds

quantify the gains of our implementation, running Segment Routing on top of IS-IS, over possible alternatives (RSVP-TE and OpenFlow).

carrier-grade networks would benefit from an SDN-like approach. Currently, network management

relies on protocols with practical limitations, either in terms of expressiveness (as for link-state IGPs, constrained by the adopted shortest-path routing model) or of scalability and overhead (like for MPLS RSVP-TE, based on per-path tunnel signaling);
requires operators to manually fine-tune those protocols and handle complex interactions between them.

3. EXPRESSING NETWORK GOALS

DEFO exposes a high-level interface, based on a small Scala DSL [16].

reference

[9] P. Quinn and T. Nadeau, “Service function chaining problem statement,” Internet draft, 2014.