RFC343

Network Working Group A. McKenzie Request for Comments: 343 BBN-NET NIC #10422 19 May 1972 Category: B.1 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 following ways.

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.

IV. We hope to accomplish release of IMPSYS 2600 on the next attempt.

 Nevertheless, we are not omniscient and may again be thwarted by
 difficulties.  Accordingly, we are scheduling the next attempt for
 Wednesday, May 31, and subsequently every Tuesday (June 6, 13, 20,
 ...) until the release is successfully accomplished.  We will
 arrange the release process so that site operator coverage is not
 required; nevertheless we hope that the normal site operator
 coverage is available in case unanticipated problems develop.
 Release of the new system will begin early in the day
 (approximately 7 a.m. EDT).  We again suggest that sites do not
 schedule production work over the network during the release
 attempt(s).  We will notify each site by phone after the release
 has been successfully completed.

 Finally, we apologize in advance for any inconvenience caused by
 the contortions required to release this new system, and thank all
 of the site operations' staffs who worked with us on May 15 for
 their cooperation.

 AAM/jm

      [ This RFC was put into machine readable form for entry ]
      [ into the online RFC archives by Ronald de Leeuw 1/99  ]