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Two changes to the IMP/Host Protocol to improve user/network communications (RFC0611) Disclosure Number: IPCOM000003684D
Original Publication Date: 1974-Feb-14
Included in the Prior Art Database: 2000-Sep-13
Document File: 3 page(s) / 7K

Publishing Venue

Internet Society Requests For Comment (RFCs)

Related People

D.C. Walden: AUTHOR


1. A Reminder

This text was extracted from a ASCII document.
This is the abbreviated version, containing approximately 39% of the total text.

Network Working Group D. Walden


NIC # 21354 February 14, 1974



1. A Reminder

When a host receives an IMP-Going Down message from its IMP (see

page 3-15 of BBN Report 1822, Specifications for the Interconnection of

a Host and an IMP), the Host should forward the information included in

the IMP-Going-Down message to its users from the network and its local

users of the network. Further, we suggest that the Host keep this

information around after the IMP has gone down, in order to tell local

users who are attempting to use the network.

In the next two sections of the RFC, we describe modifications to

the IMP/Host protocol which will allow the IMPs to distribute the same

sort of information about Hosts which are down.

2. Expansion of the Host-Going-Down Message

The type 2, Host-Going-Down, message described on page 3-1l of BBN

Report 1822 has not previously allowed for any provision by the Host for

additional information such as why, when, and for how long the Host is

going down. The following describes a modification to the Host-Going-

Down message which permits the Host to supply this additiona1


In a type 2, Host-Going-Down message, bits 17-28 give the time of

the Host's coming back up, bit-coded as follows:

bits 17-19: the day of the week the Host is coming back up. Monday is

day 0 and Sunday is day 6.

bits 20-24: the hour of the day, from hour 0 to hour 23, that the Host

is coming back up.

bits 25-28: the five minute interval, from 0 to 11, in the hour that

the Host is coning back up.


*Please file this RFC with your copy of BBN Report 1822 until that

report is updated.

All three of the above or to be specified in Universal time (i.e.,

G.M.T.). The Host may indicate that it will be coming back up more than

a week away by setting bits 17-28 all to ones. Setting all bits 17-27

to one and bit 28 to zero means it is unknown when the host is coming

back up.

Bits 29-32 of the Host-Going-Down message should be used by the Host

to specify the reason it is going down. These bits are coded as


Value Meaning

----- -------

0-4 Reserved for IMP use (see Section 3 below)

5 Scheduled P.M.

6 Scheduled Hardware Work

7 Scheduled Software Work

8 Emergency Restart

9 Power Outage

10 Software Breakpoint

11 ...