Network Host Status
A snapshot of which ARPANET hosts answered test connections between 28 February and 10 March 1972.
Westheimer, E., "Network Host Status", RFC 319, DOI 10.17487/RFC0319, March 1972, <https://www.rfc-editor.org/info/rfc319>.
@misc{rfc319,
series = {Request for Comments},
number = 319,
howpublished = {RFC 319},
publisher = {RFC Editor},
doi = {10.17487/RFC0319},
url = {https://www.rfc-editor.org/info/rfc319},
author = {E. Westheimer},
title = {{Network Host Status}},
pagetotal = 4,
year = 1972,
month = mar,
} RFC text
Network Working Group Ellen Westheimer Request for Comments: 319 BBN NIC: 9349 March 21, 1972 Updates: RFC 315 NETWORK HOST STATUS This RFC reports on the status of most Network Hosts from February 28 to March 10. The ETAC Terminal IMP (Network address 148) was installed during this period. Several Hosts are currently excluded from the daily testing. These Hosts fall into two categories: 1) Hosts which are not expected to be functioning on the Network as servers (available for use from other sites) on a regular basis for at least two weeks. Included here are: Network Address Site Computer ------- ---- -------- 134 MIT-AI PDP-10 13 Case PDP-10 15 Ames/(Paoli) ILLIAC/(B6500) 2) Hosts which are currently intended to be users only. Included here are the Terminal IMP's which are presently in the Network (AMES, MITRE, NBS and BBN). [The BBN Terminal IMP (Network Address 158) is a prototype and as such is frequently not connected to the Network, but being used to refine and debug the Terminal IMP programs.] This category also includes the Network Control Center computer (Network Address 5) which is used solely for gathering statistics from the Network. Finally, included among these Hosts are the following: Network Address Site Computer ------- ---- -------- 7 Rand IBM-360/65 73 Harvard PDP-1 12 Illinois PDP-11 19 NBS PDP-11 The tables on the next two pages summarize the Host status for this period. "STATUS OR SITE PREDICTIONS" ADDRESS SITE COMPUTER STATUS OR PREDICTION OBTAINED FROM ------- ---- -------- ------------------- -------------- 1 UCLA SIGMA-7 Server #Limited Jon Postel 65 UCLA IBM-360/91 NETRJS now Bob Braden (Telnet in April) 2 SRI(NIC) PDP-10 Server John Melvin 66 SRI(AI) PDP-10 "Soon" Len Chaiten 3 UCSB IBM-360/75 Server Jim White 4 UTAH PDP-10 Server Barry Wessler *5 BBN(NCC) DDP-516 Never Alex McKenzie 69 BBN(TENEX-A) PDP-10 Server Dan Murphy *133 BBN(TENEX-B) PDP-10 Server(Exper.) Dan Murphy *158 BBN TIP User Only (Prototype) 6 MIT(Multics) H-645 Server Mike Padlipsky 70 MIT(DM) PDP-10 Server Bob Bressler *134 MIT(AI) PDP-10 User Now Jeff Rubin *7 RAND IBM-360/65 User only Eric Harslem 71 RAND PDP-10 Server Eric Harslem *8 SDC IBM-370/155 Server Bob Long 9 HARVARD PDP-10 Server Bob Sundberg *73 HARVARD PDP-1 User Only Bob Sundberg 10 LINCOLN IBM-360/67 "Soon" Joel Winett 74 LINCOLN TX-2 Server Will Kantrowitz 11 STANFORD PDP-10 "Soon" Andy Moorer *12 ILLINOIS PDP-11 User Only John Cravits *13 CASE PDP-10 June Charles Rose 14 CARNEGIE PDP-10 "Soon" Hal VanZoeren *15 AMES/(PAOLI) ILLIAC September John McConnell (B6500) 16 AMES IBM-360/67 "Soon" Wayne Hathaway *144 AMES TIP User Only *145 MITRE TIP User Only *19 NBS PDP-11 User Only Robert Rosenthal *147 NBS TIP User Only *148 ETAC TIP User Only _________________ *Host not included in daily testing. #The NMC is a research site and would like to have prior arrangement with each user. SITE NO. SITE DATE AND TIME (EASTERN) ---- ---- ----------------------- 2/28 2/29 3/1 3/2 3/3 1200 1330 1100 1320 1700 1 UCLA-NMC O O #D O 0 65 UCLA-CCN O O #D O O 2 SRI-ARC O O #D T D 66 SRI-AI D D D D D 3 UCSB-MOD75 O O O O O 4 UTAH-10 O O #D O O 69 BBN-TENEX O O O O O 133 BBN-TENEXB #D #D O #D #T 6 MIT-Multics O O O O O 70 MIT-DMCG O H D O O 71 RAND-CSG O T O O D 8 SDC-ADEPT #D #D #D #D #D 9 HARVARD-10 O #D T O O 10 L.L.-67 H H T H H 74 L.L.-TX-2 O O #D T O 11 SU-AI D D D D D 14 CMU-10 H D D H D 16 AMES-67 D D D D D SITE NO. SITE DATE AND TIME (EASTERN) ---- ---- ----------------------- 3/6 3/7 3/8 3/9 3/10 1530 1600 1430 1400 1700 1 UCLA-NMC O O O O #D 65 UCLA-CCN D O O O O 2 SRI-ARC O O H D O 66 SRI-AI D D D D D 3 UCSB-MOD75 O O O O O 4 UTAH-10 O O O O O 69 BBN-TENEX D O O O O 133 BBN-TENEXB #D #D #D #D #D 6 MIT-Multics O O D D O 70 MIT-DMCG D D O O O 71 RAND-CSG D D O O O 8 SDC-ADEPT #D #D #D #D D 9 HARVARD-10 O O O O O 10 L.L.-67 H D H H H 74 L.L.-TX-2 O O #D O O 11 SU-AI D D D D D 14 CMU-10 D D D D D 16 AMES-67 D D D D D where D = Dead (Destination Host either dead or inaccessible [due to network partitioning or local IMP failure] from the BBN Terminal IMP.) H = 1/2 Open (Destination Host opened a connection but then either immediately closed it, or did not respond any further.) O = Open (Destination Host opened a connection and was accessible to users.) R = Refused (Destination Host returned a CLS to the initial RFC.) T = Timed out (Destination Host did not complete the ICP and open a connection within 60 seconds.) The only service currently offered by the UCLA IBM-360/91 is a Network Job Service (NETRJS), however, the BBN Terminal IMP is not equipped to test NETRJS. We are assuming that initial connection to the NETRJS logger indicates that NETRJS is also functioning. ____________ #These sites advertise that they may not have their system available at these times. [This RFC was put into machine readable form for entry] [into the online RFC archives by Hilhne Morin, Viaginie, 12/99]
AI ELI5
On this page
§1What the Report Covers
Ellen Westheimer of BBN reports on the status of most Network Hosts from February 28 to March 10, 1972. During this period the ETAC Terminal IMP (Network address 148) was installed.
Several hosts are left out of the daily testing. One group is not expected to work as servers on a regular basis for at least two weeks, namely MIT-AI (134), Case (13) and Ames/(Paoli) (15). The other group is intended for users only, including the Terminal IMPs, the Network Control Center computer (address 5) used solely for gathering statistics, and Rand (7), Harvard (73), Illinois (12) and NBS (19).
The note says which computers were checked every day and which were left off the list because they were not meant to be visited.
§2Site Status and Predictions
The first table lists each host by Network address, site and computer, with a status or prediction and the person it was obtained from. Entries include Server, Server (Exper.), User Only, Never, a month such as June or September, and the quoted word "Soon". A footnote says the UCLA NMC is a research site that would like prior arrangement with each user.
The UCLA IBM-360/91 offered only a Network Job Service (NETRJS) at the time, with Telnet expected in April. The BBN test setup could not test NETRJS, so a connection to the NETRJS logger was taken to mean it was working.
This is the big list of who is who: which computers are helpers, which are only for visitors, and which say they will be ready soon.
§3The Daily Test Codes
The second table shows test results by site on dates from 2/28 to 3/10, each tested from the BBN Terminal IMP at a recorded Eastern time. The letters mean the following. Sites flagged with a hash sign advertise they may not have their system available at that time.
DDead: the host was dead or inaccessible from the BBN Terminal IMP.HHalf open: the host opened a connection but then closed it or went silent.OOpen: the host opened a connection and was accessible to users.RRefused: the host returned a CLS to the initial RFC.TTimed out: the host did not complete the ICP and open a connection within 60 seconds.
Each computer got a one-letter grade, like open, closed, asleep or too slow to answer.
- OOpen — Host opened a connection and was accessible to users.
- H1/2 Open — Host opened a connection, then closed it or did not respond.
- TTimed out — No ICP completed and no connection opened within 60 seconds.
- RRefused — Host returned a CLS to the initial RFC.
- DDead — Host dead or inaccessible from the BBN Terminal IMP.