Network Working Group A. McKenzie
Request for Comments: 343
NIC #10422 19 May 1972
Obsoletes: RFC #331
IMP System Change Notification
As most of you probably know, our attempt to release IMPSYS 2600 on
May 15 (as discussed in RFC #331) was unsuccessful. Briefly, the
primary reasons for failure (all operational rather than programming
bugs) were: 1
) The network appears to have grown too large for us to
successfully coordinate operator intervention at all sites.
2) An unanticipated aspect of the gradual release of the new
system was the "poisoning" of IMP's running the new system by
adjacent IMP's running the old system, and vice versa. Working
around this problem made the dissemination of the new system
take much longer than anticipated.
We believe we see solutions to both of these problems and are now
ready to schedule the next attempt(s) to release IMPSYS 2600. We
hereby request all sites to cooperate with this effort in the
I. All sites with Model 516 IMP's have been contacted by telephone and
asked to set the switches on their IMP's as follows:
HALT INH - off
W.D.T. - off
AUTO RSTRT - on
MEMORY PRTCT - off
Please be sure that your switches remain set at these positions
until further notice.
II. No site should attempt to use the IMP's "Trace" routine during the
day(s) of the attempted system release.
III. Terminal IMP's may be turned off for significant portions of the
day(s) of the attempted system release. Please be patient with any
inconvenience which this causes.