Thursday, December 12, 2013

Understanding Tradeoffs in Incremental Deployment of New Network Architectures

PresenterMatthew K. Mukerjee
Authors: Matthew K. Mukerjee (Carnegie Mellon University), Dongsu Han (KAIST), Srini Seshan (Carnegie Mellon University), Peter Steenkiste (Carnegie Mellon University)

Deploying a new network architecture is difficult; after more than a decade of effort, we still haven't made the transition from IPv4 to IPv6.

The authors explore what it means to incrementally deploy a network architecture (that is, a new layer 3 protocol). They provide a framework for talking about incremental deployability by breaking the task into four parts:

  1. Picking an egress router from the source network.
  2. Picking an ingress router into the destination network.
  3. Getting to the egress router.
  4. Getting to the ingress router.
Using this framework, they compare 2 IPv6 deployment techniques (static tunnels and address mapping). Then they introduce two new deployment techniques made possible by recent innovations from the networking research community.

In summary: if incremental deployment is so easy ("just make tunnels!"), then why aren't we using IPv6 already? To realistically deploy a new layer 3 protocol, we must think carefully about how to do it, and the authors provide a framework for doing that.

Q: Are you concerned about n^2 at controllers?
A: Not really; if it's a problem, they can push the state to clients and then forget it.