A New Backward-Compatible Web Transport

Abstract

The widely-used TCP protocol for Internet communication provides a reliable and ordered transfer of a stream of bytes between two communicating devices. A significant drawback of TCP is that it does not support parallelism within its transfer, making it less suitable as a transport protocol for transferring Web pages. To reduce this problem, web browsers commonly use multiple TCP connections to stream data in parallel, which introduces its own problems and does not eliminate TCPnulls fundamental limitations. Middleboxes---devices that were not part of the original Internet architecture but are now pervasive---such as NATs, firewalls and PEPs (performance enhancing proxies) are designed and optimized for TCP only. These devices violate the Internet’s end-to-end architecture and prevent any new transport protocol from being deployed over the network. In this project, we develop a new web transfer protocol that uses unordered-TCP (uTCP), our extension of TCP that allows unordered delivery of messages without modifying the TCP protocol, to enable parallelism within a TCP stream without affecting its ability to traverse middleboxes. We discuss the design and the implementation of the new web transport protocol (uHTTP), uTCP and the user-space library uCOBS. We also present some results that show the benefits of uTCP.