Premium IP Implementation On GÉANT2

The Premium IP model defined by SEQUIN can be implemented via over-provisioning, DiffServ, ATM CBR PVC or any other technique providing guarantees for the Premium IP performance metrics. On GÉANT2, the DiffServ Expedited Forwarding Per-Hop Behaviour (EF PHB) was chosen in preference to over-provisioning because of the GÉANT2 topology and router functionalities.

The SEQUIN Premium IP specification states that, for a DiffServ-based implementation, the amount of Premium IP that can be supported on a circuit is 10% of the circuit capacity (or 30% in case the traffic of a failed circuit is re-routed to a circuit of equivalent capacity). Combined with GÉANT2’s Premium IP queuing mechanisms, this limitation allows the performance metrics to be guaranteed.

The Premium IP is destination aware – this means that the path used by the Premium IP traffic is known and ensures Premium IP utilisation on the network is optimised.

GÉANT2 accepts Premium IP flows from NRENs, and polices these flows based on their source and destination address and the capacity requested by the NREN. This access-control is needed to protect the Premium IP packets against misuse, which could "degrade" Premium IP performance. This is based on the assumption that the NRENs are themselves able to isolate the authorised Premium IP flows from others and send only these to GÉANT2 tagged as Premium IP (the others having to be re-tagged as Best Effort). If the NRENs do not re-tag their unauthorised Premium IP packets, GÉANT2 can do it for a limited amount of Premium IP requests based on source and destination IP addresses provided by the NREN or projects.

Classifiers and queuing mechanisms have been configured on most of the GÉANT2 interfaces. An input filter is used to classify Premium IP packets into a dedicated Premium IP queue. For more information, see the 'Premium IP Filter' section linked on the right-hand side.