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CMPE 257: Wireless and Mobile Networking. Spring 2005 Wireless Internetworking II. Announcements. Homework on MAC due 05.06. Midterm moved to 05.10. Today. Finish Mobile IP. FLIP. “TCP Performance in Mobile-IP” [Choong]. How does TCP perform atop Mobile IP?
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CMPE 257: Wireless and Mobile Networking Spring 2005 Wireless Internetworking II CMPE 257 Spring 2005
Announcements • Homework on MAC due 05.06. • Midterm moved to 05.10. CMPE 257 Spring 2005
Today • Finish Mobile IP. • FLIP. CMPE 257 Spring 2005
“TCP Performance in Mobile-IP” [Choong] • How does TCP perform atop Mobile IP? • What additional overhead is introduced by Mobile IP? • Tunneling/encapsulation. • Fragmentation. • Triangle routing. • Handoffs. CMPE 257 Spring 2005
Example: Triangle routing • Source of overhead: • Additional processing at HA and FA. • Additional delay due to “triangulation”. CMPE 257 Spring 2005
Goal • Determine impact on TCP performance. • Combined overhead sources. • Individual overhead sources. CMPE 257 Spring 2005
Methodology • Several scenarios that compound/isolate overhead sources. • “Baseline” scenario. • Compare performance between scenario pairs. • FTP transfer between MH and CH. • Metric: TCP throughput. CMPE 257 Spring 2005
Summary of Results • Dogleg routing as main cause of TCP throughput degradation. • Solution: route optimization. • Handoff is second. • Mobile-IP’s inherent delay in re-establish connectivity with new FA. • Solutions: • Increase frequency of router advertisements. • Use link-layer information to trigger handoff. CMPE 257 Spring 2005
FLIP [Solis] CMPE 257 Spring 2005