RAPPEP: A framework for deploying router-assisted congestion control protocols at TCP performance enhancement proxy

Router Assisted congestion control Protocols (RAPs) appear to be the most efficient solutions to the TCP performance degradation issue in high Bandwidth Delay Product (BDP) networks. Global deployment of RAPs such as XCP, VCP, and MPCP however, has been challenging due to their need for router support. In this paper, we propose RAPPEP a framework for deploying RAPs on potential congestion zones such as satellite links that are locally utilizing the architecture of TCP Performance Enhancement Proxy (PEP). Such a marriage allows for an immediate deployment of RAPs without the need for global router support, while still being able to take advantage of sophisticated RAPs. Beyond the deployed congestion zone, RAPPEP is completely transparent to the rest of the network including end nodes and other routers. Adapting from two implementations of RAPs and an implementation of TCP PEP (PEPSal), we implement and integrate RAPPEP in the Linux kernel and demonstrate its performance improvement compared to PEPSal through emulation studies.