Request for Comments:
J. Heafner
RANL
50 4/30/70
Comments on the Meyer Proposal
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We find the Meyer proposal (Note #46) to be the most acceptable to dare, for exactly the reasons that he enumerates; viz., simple, suffices for most planned uses of the Network, easy to implement, can be extended. It does not encompass everything that has been suggested recently, however, we do agree with the items that are proposed and we feel that the missing features are probably not worth doing battle over and thus delaying the specification.
We make the following comments on the seven issues rasied in
Note #47.
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- We agree with Steve that dynamic reconnection will later be required for more sophisticated uses of the Network. We also agree with the Project MAC people that it unnecessary initially. A better job can be done of dynamic reconnection given some Network experience and the specific needs of its use.
- INT is easy to implement and serves a useful purpose.
- We favor including a sub-field for instance tag identifier. We see the need for both cases; a) where multiple processes should appear indistinguishable, and b) where a given user owning multiple processes must distinguish among them. Those program parts that should not distinguish among processes should simply ignore the instance tag. Tom's suggestion to use part of the user number sub-field merely reduces the combined length of sub-fields from 32 bits to 24 bits; the problem remains.
- We disagree with both Steve and MAC in that no special structure should be imposed on the data transmitted. We prefer the "message data type" mentioned by E. I. Ancona, Note #42, page 1. An example of its use was cited in Note #39, page 2, transmit vs broadcast.
- Word boundary alignment is more attractive than double padding.
- Steve's suggestion of short-term queueing of RFCs is acceptable as an option.
- We support the UCC in Note #46 for three principle reasons:
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a) In general the user should not know the remote socket
code of the process to whom he wishes to communicate.
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b) The additional duplex connection can provide some
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superfisory control over process behavior, possibly
in conjunction with the interrupt procedure.
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c) Most of the other proposed methods demand queueing.
We think there must be a standard UCC, yet we encourage parallel experimental UCCs.
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We make two additional comments on Note #46 that were not reiterated
in Note #47.
BLK and RSM are more straightforward than previous suggestions and they do not deny multiplexing over a given link. With regard to the use of links, we refer to an example given by Bob Kahn where an intermediate IMP goes down and eats some's RFNM. This should not necessitate reconnection.
In Note #46, page 6, the statement that the UCC has the ability to close connections to a dead process is installation dependent. In our particular case the NCP is notified directly of process failure due to the particular software interface through which all processea, including NCP, must communicate.
JFH:hs
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[ This RFC was put into machine readable form for entry ]
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