TCP over Wireless: The Split Connection Approach CS294-7TCP Basics• Sliding window protocol. Window is number of outstanding packets in network.• Cumulative acknowledgement scheme.• Segment loss assumed to be as result of congestion.• In response to loss, invoke congestion contol mechanisms: decrease window size by half for every window with loss.The Problem• In wireless medium, segement loss is probably not due to congestion.• Thus, effective throughput and utilization significantly decreased [Caceres94]FHMSRMHSolutionWant to hide wireless link behavior fromportion of network!Split Connection: I-TCP• Split TCP connection into two separate connection:– FH to MSR– MSR to MH• Second TCP Connection (MTCP) [Bakre/Badrinath]• Specialized protocol (SRP) [Yavatkar/Bhagawat]Pros and Cons• Pros:– FH is shielded from wireless link behavior– Handoff is transparent to FH– Relatively easy to implement– Requires no modification to FHPros and Cons• Cons:– Loss of end-to-end semantics– Efficiency: unnecessary data processing (copying) at MSR– Large handoff latencies due to non trivial amount of state transfer between
View Full Document