Logger Protocol error
A notice pointing out a contradiction between two protocol specifications.
Meyer, E., "Logger Protocol error", RFC 79, DOI 10.17487/RFC0079, November 1970, <https://www.rfc-editor.org/info/rfc79>.
@misc{rfc79,
series = {Request for Comments},
number = 79,
howpublished = {RFC 79},
publisher = {RFC Editor},
doi = {10.17487/RFC0079},
url = {https://www.rfc-editor.org/info/rfc79},
author = {E. Meyer},
title = {{Logger Protocol error}},
pagetotal = 1,
year = 1970,
month = nov,
} RFC text
Network Working Group Edwin W. Meyer, Jr.
Request for Comments: 79 MIT Project MAC
NIC 5601 November 16, 1970
Logger Protocol Error
A conflict was recently discovered between the official NCP protocol
as described in protocol document 1 and the logger protocol as
described in RFC 66 by Steve Crocker. Steve suggested that we put
out an RFC to alert the network community to this point.
In RFC 66, it is proposed that an ALL allocate command be sent
immediately following an RTS or STR request for connection. This
conflicts with the restriction stated in Protocol Document 1 that an
ALL command can be given only for an "open" connection.
To not be required to handle an ALL command before a connection is
established is a simplifying restriction that an NCP implementation
may take advantage of. For example, the Multics NCP is currently
designed this way. For this reason, and also because we believe that
the NCP protocol should not be changed now except for critical
reasons it is felt that the proposed logger protocol should be
modified to agree with the existing NCP protocol.
[ This RFC was put into machine readable form for entry ]
[ into the online RFC archives by Alison De La Cruz 11/00 ]
AI ELI5
On this page
§1The Protocol Conflict
RFC 79 documents a protocol conflict discovered by E. Meyer of MIT Project MAC. The conflict exists between the official NCP protocol as defined in Protocol Document 1 and the logger protocol proposed in RFC 66 by Steve Crocker.
According to RFC 66, an ALL (allocate) command should be sent immediately following an RTS (request to send) or STR (send-to-receive) request for connection. However, Protocol Document 1 restricts ALL commands to only be issued for connections that are already open, not during the connection setup phase.
One protocol said you could do action X at point A in the process, but another protocol said you could only do it at point B after the connection was already working.
§2Why This Matters
This is not a trivial difference. The restriction that ALL can only be used on open connections is described as a simplifying constraint that NCP implementations could take advantage of. For example, the Multics NCP was already designed with this restriction in mind. Changing the core protocol to allow ALL before connections are open would require redesigning Multics and potentially other implementations already under development.
Some systems were already being built with the assumption that you couldn't do this during setup, so changing it would break their work.
§3Decision and Impact
The RFC concludes that the logger protocol should be modified to agree with the existing NCP protocol rather than changing the core protocol. The rationale was to avoid disrupting implementations already in progress and because the authors believed that the NCP protocol should not be changed except for critical reasons. This decision prioritized stability and compatibility over adopting the new feature proposed in RFC 66.
Rather than make everyone redesign their systems, they decided to change the logger protocol to match what people were already building.