WLC40-3: A Mechanism for Enhancing VoIP Performance over Wireless Networks using Embedded Mobility-Specific Information in RSVP Objects

Mobile IP is the standardized IETF proposal to facilitate terminal mobility in wireless IP networks while RSVP is considered the integrated services standard in providing QoS guarantees. Since the former offers IP mobility and the later provides QoS guarantees, one would think that simply superimposing the two technologies would yield an optimum solution. This however is evidently not the case since RSVP was initially designed with static nodes in mind. A key issue relates to the IP-in-IP encapsulation of packets. This conceals the identity of RSVP packets from intermediate routers which fail to recognize them, thereby not reserving the necessary resources. Another issue arises in the event of a handoff where the interruption in QoS causes a notable degradation in application level performance. To address these issues, we propose a mobility extension which is fully compatible with RFC2205, and can therefore be implemented with minimal changes to end nodes. We assess our proposal by evaluating VoIP performance using parametric simulations. Our results indicate 27.9% improvement in QoS interruption when using mobile IP, and 12.5% with hierarchical mobile IP.