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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.
Service Description
GÉANT Peering service is implemented as a feature of the GÉANT IP service, for the eligible partners. According to the Peering Policy document, access to the GÉANT Peering service is currently restricted to entities serving a research and/or education community in one or more countries, and that are eligible for funding under the European Union's Horizon 2020 Programme. These countries are:
- Member States of the European Union;
- Accession Countries (i.e. those countries in the process of acceding to the European Union);
- Candidate Countries (i.e. those countries recognised by the European Union as candidates for accession);
- Associated Countries (i.e. those countries formally associated to FP7);
- International Cooperation Partner Countries (i.e. those countries classified by the European Commission as low, lower-middle, or upper-middle income countries).
Under this categorisation all GN4 project partners receiving GÉANT connectivity and services can connect to the GÉANT peering service. In addition, regional networks (e.g. CAREN, TEIN, RedCLARA) will be provided with access to the peering service on request.
To ensure each NREN has greater control over their traffic and the ability to select who they are receiving traffic from, a set of BGP (Border Gateway Protocol) communities will be enabled to offer per direct peer and per IX granularity. This means that each direct peer will have its own BGP community not only giving the option to each NREN to block the traffic from any given direct peer but also to control the announcements made to each direct peer, the same will apply for each Internet Exchange.
Each BGP community will be maintained as part of the general BGP commodity policy document maintain by the GÉANT Operations team. The general policy document is available to all NRENs on the Partner Portal and can also be found the Peering Documents folder.