12.1 Introduction

Telecommunications networks are rapidly progressing towards an all-IP architecture. This trend is not restricted to fixed networks. Second generation cellular networks have been modified to provide limited data services, and third generation systems currently undergoing roll-out have been designed to deliver IP connectivity to the end user [1, 2]. Projecting technological trends, it is seen as inevitable that the future global telecommunications network will consist of a routed/switched IP core (much of which will be optical) accessed via a wide range of edge technologies. Many of these edge technologies will support mobility based on the continuing advancements in wireless technology. Internet service providers will increasingly want to support both fixed and mobile users. With IP routing technology being pushed out to the network's edge, it becomes less cost effective to support the various modes of layer-2 edge mobility management that accompany today's cellular and PCS technologies. Rather, unified solutions become advantageous to domain operators, wherein mobility management becomes an integral component of an IP layer routing protocol.

Internet routing protocols have been traditionally designed from an assumption that the location of an IP interface in the topology is static. In addition, they assume that address allocation within the topology will aim to provide multiple levels of IP address aggregation such that routing protocols can deal with address prefixes, rather than large numbers of host routes. Within this framework, traditional intra-domain protocols, such as OSPF, need only react to infrequent changes to the...