ABSTRACT
The original implementation of the Internet assumed a set of static nodes talking to each other. This approach sets clear boundaries between different network topologies and allows mobility only through patches and adaptations that make true seamless mobility very difficult. This is due to the use of IP addresses that contain geographic semantics and are inherently not mobile and domain names that are intrinsically linked to these static servers. In recent years, the total number of mobile devices has outpaced that of static ones and supporting mobility in Internet Protocol (IP) networks has become a a crucial step toward satisfying the nomadic communication paradigms on the current Internet. Session Initiation Protocol (SIP) presents one approach toward supporting IP mobility. Additionally, SIP is increasingly gaining in popularity as the next generation multimedia signaling and session establishment protocol. It is anticipated that the SIP infrastructure will be extensively deployed all over the Internet and it has already been accepted as the signaling protocol of preference for many multimedia frameworks. In this paper, we explore the use of persistent identifiers to provide a secure and efficient approach to interdomain SIP mobility. We will discuss the issues associated with SIP session mobility and the different approaches used to provide persistent identification that expedites mobility; some of which are explicitly applied to SIP. We will
Services, Technologies,
later illustrate SIP mobility and security through the implementation of an identification framework to application-level SIP addressing by introducing a level of indirection on top of the traditional SIP architecture. We refer to our approach as the Handle SIP (H-SIP). H-SIP leverages the current SIP architecture abstracting any domain binding from users. Our approach to mobility is both secure and user-controlled and has shown through our inter-domain authentication and call routing experiments to be as scalable as current solutions for static networks and more scalable and reliable in the presence of mobility.
