Mobile Inter-networking with IPv6 : Concepts, Principles and Practices

17

Hierarchical Mobility Management

Engineers like to solve problems. If there are no problems handily available, they will create their own problems. Normal people don’t understand this concept; they believe that if it ain’t broke, don’t fix it. Engineers believe that if ain’t broke, it doesn’t have enough features yet.    –Scott Adams

—

17.1 INTRODUCTION

Although the fast handovers protocol is primarily concerned with reducing latency and packet loss during handovers, it is, in a sense, independent of the actual mobility protocol used over the Internet. The protocol does not affect the Mobile IP protocol itself; it ensures that the latencies in the Mobile IP protocol are addressed. In other words, a mobile node would still perform the Mobile IPv6 operations including Binding Update to its home agent, Return Routability with its correspondents, and subsequent updates to their Binding Cache entries. These Mobile IPv6 operations can be seen as introducing additional signaling overhead in certain deployments. The Hierarchical Mobile IPv6 (HMIPv6) protocol is designed primarily to address this overhead. However, it turns out that the protocol can also be useful in a limited sense for location privacy in terms of the IP addresses revealed to the correspondents. We will discuss this topic in Chapter 23.

Fig. 17.1 Hierarchical Mobility Reference Model

Since Hierarchical Mobile IP is ...