Hardware-based packet forwarding for the transport layer

Abstract

This document describes, among other things, improved methods, systems, and apparatus for relaying packets on computer networks. Preferably, the relay function is accelerated at a host by implementing selected forwarding functions in hardware, such as the host's network interface card, while upper software layers at the host retain at least some access to the packet flow to handle more complex operations and/or monitoring. In a so-called 'split TCP' arrangement, for example, a relay host terminates a first TCP connection from a given host and forwards packets on that connection to another given host on a second TCP connection. The relay host has a TCP forwarding table implemented at the device level, configurable by a relay management application running in the kernel or user-space. Special forwarding table modes may be used to enable full-TCP protocol support while also taking advantage of hardware acceleration.