The Current Flow-control Scheme for IMPSYS.

While Vint's notes on IMPSYS flow-control from the March 16, 1972,

meeting (RFC 442) seem reasonably accurate and while he does cite our

Quarterly Technical Report #13, he might have done better to cite BBN's

two formal publications relevant to the IMPSYS flow-control scheme:

1 McQuillan et al, Improvements in the Design and Performance of

the ARPA Network, Proceedings AFIPS 1972 FJCC, pp. 741-754.

2 BBN Report 1822, Specifications for the Interconnection of a

Host and an IMP, December 1972 Revision, section 3, pp. 17-35.

Reference 2 is particularly important reading for NCP programmers -

things have recently changed somewhat.

The inter-IMP acknowledgement mechanism, described in the last

section of Vint's RFC 442, is also described in reference 1 and an

almost identical mechanism is described in Appendix F of reference 2.

The acknowledgement is of only intellectual interest to most Hosts as it

is transparent to network users. However, the description in reference

2 is of vital interest to so-called Very Distant Hosts.

[ This RFC was put into machine readable form for entry ]

       [ into the online RFC archives by Alex McKenzie with    ]
       [ support from GTE, formerly BBN Corp.             9/99 ]

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