[Docs] [txt|pdf]

This is a modified version of the Internet RFC suitable for machine-translating. Original version is available here: RFC449

Network Working Group                                       Dave Walden
RFC # 449                                                   BBN-NET
NIC # 14133                                                 Jan. 6, 1973
Updates RFC 442

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 ]

Walden [Page 1]

    Html markup produced by rfcmarkup 1.121, available from

inserted by FC2 system