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This service provides a peering service that compliments the existing commodity connectivity of the NREN networks. The service provides access to a wide number of Internet prefixes as possible and contues to evolve overtime through utilizing public Internet exchange peering to create a presence and build relations with commercial networks. Once these relations are established the aggregated traffic of participating networks can be used to reduce the requirement of public peering (transit) and instead using private interconnects with large preferably Tier1 and Tier2 networks. A strategic set of locations that operate as mission critical hubs for today's Internet operations are a natural and logical choices. . In Europe these are commonly, Amsterdam, Frankfurt, London and Paris.
Technical Description
Following the recommendations from the Access Port Managers and requirements from the GEANT Exec, GEANT Operations is working to introduce a new VRF (Virtual Routing and Forwarding) for REN to Internet. This will mean that Peering and DWS traffic will run on their own dedicated routing instance allowing for uniform routing policies independent from the REN to REN traffic.
To accommodate the requirement for clear separation of REN to Internet traffic the new VRF will have its own AS number allowing for clear administrative distinction from the general GEANT traffic. The AS number for the GEANT REN2I traffic will be AS 21320.
About route selection and exit path, BGP is used to select the best path to reach an external network. BGP offers a set of attributes that allows networks to engineer how traffic is distributed - local preference (LP), AS path length and multiple exit discriminator (MED).
Both LP and MED are methods of traffic engineering for egress and ingress respectively. Use of these parameters allows the selection of the highest performance, lowest latency and lowest cost route for in and outbound traffic. Universally, ASs tend to prefer routes using LP in sequence of customer, peer and finally upstream to transit. When all other items are equal, traffic will prefer a shorter AS path to a longer one, typically this is only taken into account when going upstream to transit and a decision is required as to which upstream provider to use.
Finally, in the case of peers across multiple internet exchanges (IX), typically the IX closest to the NREN will be chosen as the egress point.