Date Added: Jun 2010
As routing takes place in an entirely distributed system where local routers have no direct access to globally consistent network state information, a routing algorithm has to make uncertain forwarding decisions. As the network state may change, due to failures or new adoptions of net-works, routing algorithms have to adapt themselves to the new situation. This network convergence phase should be carried out as quickly and precisely as possible. Besides the problem of generating the proper updates for the locally distributed routers, the problem of forwarding the routing updates is also manifest: routing updates travelling along routing loops may become obsolete or outdated.