Metarouting
Tim Griffin
There is a shortage of Internet routing protocols that meet the needs
of network engineers. This has led to the Border Gateway Protocol
(BGP) being pressed into service as an interior routing protocol,
despite the fact that it was designed for exterior routing and that it
lacks convergence guarantees. Defining, standardizing, and deploying
routing protocols, or even minor changes to existing protocols, is
very difficult. I'll present a solution called Metarouting, which is
based on the definition of languages that define routing protocols and
that can be implemented on routers. Metarouting allows a network
operator the freedom to implement and use new routing protocols. The
approach is based on three ideas. First, the Routing Algebra
framework of Sobrinho [SIGCOMM 2003] is used as the theoretical basis
for routing policy languages. Second, we enforce a clean separation
of protocol mechanisms (link-state, path-vector, adjacency
maintenance, and so on) from routing policy (how routes are described
and compared). Third, metarouting employs a Routing Policy
Meta-Language (RPML) that allows for the construction of a large
family of routing policy languages. I'll present an RPML having the
key property that correctness conditions --- guarantees of convergence
with respect to the chosen mechanisms --- can be derived automatically
for each expression defining a new routing policy language.
This is joint work with Joao Sobrinho (Instituto Superior Tecnico, Portugal)
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