Emulating Border Flow Policing using Re-PCN on Bulk Data

Scaling per flow admission control to the Internet is a hard problem. The approach of combining Diffserv and pre-congestion notification (PCN) provides a service slightly better than Intserv controlled load that scales to networks of any size without needing Diffserv's usual overprovisioning, but only if domains trust each other to comply with admission control and rate policing. This memo claims to solve this trust problem without losing scalability. It provides a sufficient emulation of per-flow policing at borders but with only passive bulk metering rather than per-flow processing. Measurements are sufficient to apply penalties against cheating neighbour networks.