Increasing TCP Throughput with an Enhanced Internet Control Plane

CHART seeks to improve the performance of operational DoD internets through the introduction of an intelligent network overlay. TCP performance ? particularly between CONUS and forward-deployed components located in combat theaters ? can be severely degraded due to high loss rates and long latencies. The lack of current information about network conditions in the core NIPR- net/SIPRnet further compounds the problem, because end hosts lack the data required to make intelligent routing decisions. Deploying CHART's enhanced control plane improves measurement and monitoring of unreliable communication links to provide current network state information to routers implemented in both software and hardware, enabling intelligent routing around faulty links. We describe the design of software and hardware routers sharing a common network `sensing' infrastructure, the implementation of end-to-end Quality of Service via flow state aware routers, and a new network-aware TCP/IP stack for Linux end systems. Performance test results demonstrate that bulk file transfer throughput can be increased by as much as an order of magnitude in networks with severely impaired communication links.