Delegated IP: A Mobile IPv6-Based Protocol to Support Session Delegation

User-Centric Mobility for Multimedia Communication: Experience and Evaluation from a Live Demo

“…The most recent paradigms for session migration aim at maintaining the same IP address for the whole session duration, VNAT [5] and DIP [6] first introduced this concept. Both of them envision a sort of "loan" of the original IP address coupled with a MIPv6 architecture; the application and transport protocols at the new terminal use the borrowed address, which is translated into a usable real address through specific mechanisms.…”

“…Delegated IP (DIP) [6] exploits the Return Routability of MIPv6 to redirect packets towards a target node. The original host "delegates" the use of its Home Address to the target node; DIP provides a DIP IP Adaptation Layer (DIAL) and a DIP Transport Adaptation Layer (DTAL) at the target node to receive packets addressed to a thirdparty from the MIPv6 infrastructure and to deliver them to a local socket.…”

“…For example, in VNAT the local host does not keep track of session migrated elsewhere; port number conflicts are possible at the corresponding host whether this latter tried to set up another session before the previous were closed [7] (this is quite likely, as each application usually uses the same port numbers). On the other hand, in DIP the corresponding host cannot reach the local host for the whole duration of the migration because of a route update towards the target node (see [6] for protocol details).…”

“…Rather surprisingly, many papers dealing with session migration only describe mobility protocols and pervasive environments, without any evidence of performance measurements from working testbed [12], [13], [14], [15], [16], [17], [18], [19] or even any proof of implementation [5], [6]; when some numerical results are available, they only concern quantitative measurements in few and very simple scenarios [4], [11], [20], [21]. A more accurate performance analysis is only available for the PA, in different networking scenarios and for different multimedia applications [8].…”

“…Requests of setting up a session coming from Corresponding Nodes (CNs) are forwarded by the Proxy to the current device LT1. Before answering the INVITE message, this terminal adds the PA to its network interface and runs the MIP client registering the PA as the HoA; from now on, the SIP user agent begins using the PA just set up and all signaling and media are routed within the MIP architecture through the HA 6 . The same mechanism also applies if the mobile user's terminal initiates the session; the only difference is that the PA is set up before sending the INVITE message.…”