Technical Report Number
Over the last few years, a number of research groups have made considerable progress on the design of high speed networks- on the order of a few hundred Mbps to the few Gbps. The emphasis of this work has been on the design of packet switches and on the design of network access protocols. However, this work has not yet addressed the internetworking and transport level issues in the high speed internet. As part of our effort on the design of VHSI model, we considered the appropriateness of recently proposed transport protocols, NETBLT and VMTP, as candidates for the transport protocol for our VHSI model. The summary of the results of the study is that NETBLT and VMTP have contributed a number of interesting ideas to the design of transport protocols, and they do improve upon TCP within the current Internet model for the applications they were originally designed for. However, we believe that these protocols are not appropriate solutions for the VHSI model, because the underlying assumptions and trade-offs that these protocols are based on the very different in the VHSI model. For example, the VHSI model assumes a quasi-reliable connection-oriented internet protocol (as opposed to the current unreliable datagram IP), which can make performance guarantees and can ensure that the internet is congestion free (almost all of the time). Also the network speeds in the VHSI are the few order of the magnitude more than what NETBLT and VMTP assume. We argue that the transport protocols in the VHSI model should avoid end-to-end flow control as much as possible, and make the end-to-end error control application specific and independent of the end-to-end latency. In general, the transport protocols should be simpler, designed to be mostly implemented in VLSI, well integrated with the host architecture and operating system, and targeted for a specific class of applications.
Bhatia, Anil; Sterbenz, James; and Parulkar, Gurudatta M., "Comments on Proposed Transport Protocols" Report Number: WUCS-88-30 (1988). All Computer Science and Engineering Research.