Lars Eggert
NEC Network Laboratories
Heidelberg, Germany
Wednesday, August 16 at 10:00am PDT
11th floor large CR

TCP Extensions for Intermittently Connected Hosts

Internet users are increasingly mobile and their hosts may often only intermittently connected to the Internet. When such hosts communicate using the current Internet protocols, intermittent connectivity can significantly decrease performance and even cause connections to fail altogether. This talk presents measurements of the behavior of Internet communication across a dynamically changing, intermittently connected
path. An analysis of the experimental results finds that address changes together with transport-layer timeout and retransmission behaviors are the main limiting factors. Based on these experimental results, this talk proposes a solution that combines the Host Identity Protocol (HIP) with two new protocol enhancements, the TCP Abort Timeout Option and the TCP Retransmission Trigger. Detailed experiments with HIP and a prototype implementation of these protocol enhancements show that they tolerate address changes and arbitrary-length disconnections while significantly increasing performance under intermittent connectivity to within 86-96% of a scenario with constant connectivity.

Bio:
Lars Eggert is a researcher at NEC Network Laboratories in Heidelberg, Germany. He received his Ph.D. in Computer Science in the fall of 2003 from the University of Southern California, where he was a graduate research assistant at the USC Information Sciences Institute (ISI). He has worked on projects ranging from web caching to TCP performance analysis, IP security, virtual networks and network architecture. His dissertation focuses on background use of idle resources to increase system performance. He is a member of the ACM, IEEE and an active participant in various IETF and IRTF working groups.