1. CMPE 257 Spring 20051 CMPE 257: Wireless and Mobile Networking Spring 2005 Wireless Internetworking II

2. CMPE 257 Spring 20052 Announcements Homework on MAC due 05.06. Midterm moved to 05.10.

3. CMPE 257 Spring 20053 Today Finish Mobile IP. FLIP.

4. CMPE 257 Spring 20054 “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.

5. CMPE 257 Spring 20055 Example: Triangle routing Source of overhead: Additional processing at HA and FA. Additional delay due to “triangulation”.

6. CMPE 257 Spring 20056 Goal Determine impact on TCP performance. Combined overhead sources. Individual overhead sources.

7. CMPE 257 Spring 20057 Methodology Several scenarios that compound/isolate overhead sources. “Baseline” scenario. Compare performance between scenario pairs. FTP transfer between MH and CH. Metric: TCP throughput.

8. CMPE 257 Spring 20058 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.

9. CMPE 257 Spring 20059 FLIP [Solis]