RFC 333 (rfc333) - Page 2 of 26
Proposed experiment with a Message Switching Protocol
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RFC 333 MESSAGE SWITCHING PROTOCOL EXPERIMENT May 1972 SOME BACKGROUND Over the past several weeks there has been considerable informal discussion about the possibility of implementing, on an experimental basis, in several of the ARPA Network Host Computers, NCPs which follow a protocol based on the concept of message switching rather than the concept of line switching (see the parenthetical sentence in the first paragraph of page 6 of NIC document 8246, Host/Host Protocol for the ARPA Network). Party to this discussion have been Bob Bressler (MIT/Dynamic Modeling) Steve Crocker (ARPA), Will Crowther (BBN/IMP), Tom Knight (MIT/AI), Alex McKenzie (BBN/IMP), Bob Metcalfe (MIT/Dynamic Modeling), Dan Murphy (BBN/TENEX), Jon Postel (UCLA/NMC), and Dave Walden (BBN/IMP). Several interesting points and conclusions have been made during this discussion: 1. Bressler has implemented a message switched interprocess communication system for the Dynamic Modeling PDP-10 and has extended it so it could be used for interprocess communication between processes in the Dynamic Modeling PDP-10 and the AI PDP-10. He reports that it is something like an order of magnitude smaller than his NCP. 2. Murphy has noted that a Host/Host protocol based on message switching could be implemented experimentally and run in parallel with the real Host/Host protocol using some of the links set aside for experimentation. Further, Murphy has noted that if this experimental message switching protocol were implemented in TENEX, a number of (TENEX) sites could easily participate in the experiment. 3. It is the consensus of the discussants that Bressler should take a crack at specifying a message switching protocol* and that if this specification looked relatively easy to implement, a serious attempt should be made by Murphy and Bressler to find the resources to implement the experimental protocol on the two BBN TENEX and the MIT Dynamic Modeling and AI machines. 4. MSP was chosen as the acronym for Message Switching Protocol, and links 192-195 were reserved for use in an MSP experiment. ------------- *This note fulfills any obligation Bressler may have incurred to produce an MSP specification. Bressler, et al. Experimentation
