Movatterモバイル変換

Network Working Group                        John M. McQuillanRequest for Comments # 406                   Bolt Beranek and NewmanNIC # 12111                                  10 October 1972Categories B.1Updates RFC # 381                    Scheduled IMP Software Releases                    -------------------------------     This note is a reminder that the procedures suggested inRFC # 381 for scheduling IMP software maintenance have nowbeen in effect for a period of about two months.  Two pointsapparently require re-emphasis:     1)   We reserve the hour from 7 to 8 a.m. eastern timeevery Tuesday as the time when IMPs can be reloaded.  We willprobably not use this period every Tuesday, but we do reservethis period every Tuesday.  The software maintenance time periodis in addition to the hardware preventive maintenance scheduledat each site.     2)   We now send an IMP - Going - Down message to allthe Hosts at the site which contains information on the timethat the IMP is going down, the expected duration, and thereason.  We try to send out this message an hour before soft-ware releases, and five to ten minutes before scheduled pre-ventive maintenance.  Further, we will also notify the Hostsat a site, whenever possible, when it is necessary to stop theIMP on an unscheduled basis.  Finally, 30 seconds before the                                                                [Page 1]

IMP goes down, a second IMP - Going - Down message will besent to the Hosts informing them that the IMP is going downimmediately.  The format of the IMP - Going - Down messageis as follows:bits 1 - 4  -  all zerobits 5 - 8  -  0010bits 9 - 16 -  all zerobits 17 - 32 -  coded as follows:          All bits zero - going down in 30 seconds          Bits 17, 18 = 01 - scheduled hardware PM          Bits 17, 18 = 10 - scheduled software reload          Bits 17, 18 = 11 - emergency reload on restart          Bits 19 - 22 - how soon the IMP is going down,                         in 5 minute units.          Bits 23 - 32 - how long the IMP will be down, in                         5 minute units.    [ This RFC was put into machine readable form for entry ]    [ into the online RFC archives by BBN Corp. under the   ]    [ direction of Alex McKenzie.                      1/97 ]                                                                [Page 2]