Premium IP Implementation On GÉANT

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 GÉANT, the Diffserv Expedited Forwarding Per-Hop Behaviour (EF PHB) was chosen in preference to over-provisioning because of the GÉANT 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 20% in case the traffic of a failed circuit is re-routed to a circuit of equivalent capacity). Combined with GÉANT’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.

GÉANT accepts Premium IP aggregate 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 GÉANT 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, GÉANT 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 GÉANT interfaces. An input filter is used to classify Premium IP packets into a dedicated Premium IP queue. For more information, see the 'Configuration' section linked opposite.

The deployment status of the service on GÉANT can be viewed via the link opposite.