Path computation in multi-layer multi-domain networks: A language theoretic approach

TL;DR

This paper introduces a novel automata-theoretic model for multi-layer multi-domain networks, enabling efficient path computation considering protocol encapsulation and decapsulation, which traditional graph models cannot adequately handle.

Contribution

It proposes a new Push-Down Automaton model to accurately represent heterogeneous networks with encapsulation capabilities, along with polynomial algorithms for optimal path computation.

Findings

Polynomial algorithms for shortest path in hops or encapsulations

Model captures protocol encapsulation/decapsulation with PDA

Reduces manual configuration and loop issues

Abstract

Multi-layer networks are networks in which several protocols may coexist at different layers. The Pseudo-Wire architecture provides encapsulation and de-capsulation functions of protocols over Packet-Switched Networks. In a multi-domain context, computing a path to support end-to-end services requires the consideration of encapsulation and decapsulation capabilities. It appears that graph models are not expressive enough to tackle this problem. In this paper, we propose a new model of heterogeneous networks using Automata Theory. A network is modeled as a Push-Down Automaton (PDA) which is able to capture the encapsulation and decapsulation capabilities, the PDA stack corresponding to the stack of encapsulated protocols. We provide polynomial algorithms that compute the shortest path either in hops or in the number of encapsulations and decapsulations along the inter-domain path, the latter reducing manual configurations and possible loops in the path.