A Policy-aware Switching Layer for Data Centers

Summary

This paper proposes PLayer, a policy aware layer-2 for data centers. PLayer is made up of inter-connected pswitches, policy-aware switches. Middleboxes can then be plugged into the pswitches, moving them off the network path. The pswitches are responsible for deciding which middleboxes each packet needs to go through and forwards the packet accordingly.

The main principles of PLayer are:
1) separating policy from reachability - middleboxes traversed are determined explicitly by a policy and not implicitly for network path selection mechanisms.
2) taking middleboxes off the physical network path - middleboxes are removed from choke points

PLayer aims to provide the following properties:
1) correctness
2) flexibility
3) efficiency

When forwarding packets, the PLayer uses centralized policy and middlebox controllers to setup and maintain the rule tables at the pswitches.

Critique & Questions

I thought this was a very well written and well structured paper. They did a good job at explaining the current problems in data centers. I also liked that they went into detail on how PLayer could be incorporated into the current infrastructure with minimal changes.