Protection of routers in a telecommunications network

A set of router table entries is used to form a set of p-cycles in an Internet provider network, which have no capacity unless they are required to carry packet traffic. If a packet is intended to travel over a route between nodes (12-14) and a node (10) has failed, the source router (12) detours the packet onto a p-cycle after encapsulating it in a p-cycle packet. Routers then pass the packet to its destination node. An independent claim is included for a telecommunication network and for a data packet. A method of configuring a node in an IP network by creating a set of router table entries which form a set of virtually preconfigured cyclical routes, or p-cycles, within the IP network. This set of p-cycles is virtual in the sense that the only resources which they normally consume are routing table entries. No transmission capacity is required for them, unless/until they are used to carry packets (traffic.) These p-cycles sit idle and unused until a failure takes place. The routers surrounding the failure then use these p-cycles to route packets, which normally would be lost, around the failure. A router having an entry in its router table identifying the p-cycle, together with an associated port, is also disclosed, and also a data packet that may use a p-cycle to get to its destination.