Depeering
By definition, peering is the voluntary and free exchange of traffic between two networks, for mutual benefit. If one or both networks believes that there is no longer a mutual benefit, they may decide to cease peering: this is known as depeering. Some of the reasons why one network may wish to depeer another include:
- A desire that the other network pay settlement, either in exchange for continued peering or for transit services.
- A belief that the other network is "profiting unduly" from the settlement free interconnection.
- Concern over traffic ratios, which is related to the fair sharing of cost for the interconnection.
- A desire to peer with the upstream transit provider of the peered network.
- Abuse of the interconnection by the other party, such as pointing default or utilizing the peer for transit.
- Instability of the peered network, repeated routing leaks, lack of response to network abuse issues, etc.
- The inability or unwillingness of the peered network to provision additional capacity for peering.
- The belief that the peered network is unduly peering with your customers.
- Various external political factors (including personal conflicts between individuals at each network).
In some situations, networks who are being depeered have been known to attempt to fight to keep the peering by intentionally breaking the connectivity between the two networks when the peer is removed, either through a deliberate act or an act of omission. The goal is to force the depeering network to have so many customer complaints that they are willing to restore peering. Examples of this include forcing traffic via a path that does not have enough capacity to handle the load, or intentionally blocking alternate routes to or from the other network. Some very notable examples of these situations have included:
- BBN Planet vs Exodus Communications
- PSINet vs Cable & Wireless
- AOL Transit Data Network (ATDN) vs Cogent Communications
- Teleglobe vs Cogent Communications
- France Telecom vs Cogent Communications
- France Telecom (Wanadoo) vs Proxad (Free)
- Level 3 Communications vs XO Communications
- Level 3 Communications vs Cogent Communications
- Telecom/Telefónica/Impsat/Prima vs CABASE (Argentina)
- Cogent Communications vs TeliaSonera
- Sprint-Nextel vs Cogent Communications
Read more about this topic: Peering