Connectionless Building Blocks For Intra and Inter-Domain Traffic Engineering

We propose new building blocks for connectionless intra-domain and inter-domain traffic engineering (TE) in the Internet. The key idea is to capture an intradomain path, AS-path or an exit route as a 32-bit hash in the packet header. This hash allows explicit “source” directed routing without signaling or high per-packet overhead, while enabling an incremental upgrade strategy for OSPF and BGP. This paper overviews the building blocks and focuses on the inter-domain case, where we consider the problems of a) explicit border router choice and b) an explicit AS path choice. The latter problem in general requires a tradeoff in terms of increased inter-AS control traffic, whereas the former problem can be solved within an AS with partial upgrades. Such explicit routing has the potential to allow a more direct, finer-grained policy control of how traffic is mapped to routes. Simulation and implementation/experimental results illustrate the operation of these building blocks.