Network Host Status
Checking which network hosts were working in June 1972
Westheimer, E., "Network Host Status", RFC 362, DOI 10.17487/RFC0362, June 1972, <https://www.rfc-editor.org/info/rfc362>.
@misc{rfc362,
series = {Request for Comments},
number = 362,
howpublished = {RFC 362},
publisher = {RFC Editor},
doi = {10.17487/RFC0362},
url = {https://www.rfc-editor.org/info/rfc362},
author = {E. Westheimer},
title = {{Network Host Status}},
pagetotal = 4,
year = 1972,
month = jun,
} RFC text
Network Working Group Ellen Westheimer
NIC #10604 BBN
RFC #362 28 June 1972
Categories: F, G.3
Updates: RFC #353
Obsoletes: None
NETWORK HOST STATUS
This RFC reports on the status of most Network Hosts from June 5
to June 16. During this period the MIT Math Lab PDP-10 (Network
address 198) became a server.
No testing was done on June 6 due to an attempt to install the
new IMP system. No testing was done on June 9 as the prototype
Terminal IMP was being used for software debugging.
On June 16 the ARPA Terminal IMP (Network 156) was installed in
Arlington, Virginia.
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. The only Host in this category is the PDP-10 at Case
(Network address 13).
2) Hosts which are currently intended to be users only. Included here
are the Terminal IMPs, which are presently in the Network (AMES,
MITRE, NBS, ETAC, USC, GWC, NOAA, RADC, SAAC, BELVOIR, ARPA, and
BBN*). 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
23 USC IBM-360/44
The tables on the next two pages summarize the Host status
for this period.
________________
*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.
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 June)
2 SRI (NIC) PDP-10 Server Jim White
66 SRI (AI) PDP-10 Server Len Chaiten
3 UCSB IBM-360/75 Server Ron Stoughton
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
6 MIT (Multics) H-645 Server Mike Padlipsky
70 MIT (DM) PDP-10 Server Bob Bressler
134 MIT (AI) PDP-10 Server Jeff Rubin
198 MIT (ML) PDP-10 Server 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 Server Andy Moorer
*12 ILLINOIS PDP-11 User Only John Cravits
*13 CASE PDP-10 June Charles Rose
14 CARNEGIE PDP-10 Server Hal VanZoeren
15 AMES ILLIAC Server John McConnell
(PDP-10)
16 AMES IBM-360/67 "Soon" Wayne Hathaway
*144 AMES TIP User Only
*145 MITRE TIP User Only
*146 RADC TIP User Only
*19 NBS PDP-11 User Only Robert Rosenthal
*147 NBS TIP User Only
*148 ETAC TIP User Only
*23 USC IBM-360/44 User Now James Pepin
*151 USC TIP User Only
*152 GWC TIP User Only
*153 NOAA TIP User Only
*154 SAAC TIP User Only
*156 ARPA TIP User Only
*158 BBN TIP User Only
(Prototype)
______________
*Host not included in daily testing.
#The NMC is a research site and would like to have prior arrangement
with each user.
NO. SITE DATE AND TIME (EASTERN)
--- ---- -----------------------
6/5 6/7 6/8 6/12 6/13 6/14 6/15 6/16
1330 1600 1200 1530 1230 1100 1230 1700
1 UCLA-NMC O O O O O #D O O
65 UCLA-CCN* O O O O O #D O O
2 SRI-ARC O D D O O O O O
66 SRI-AI O D T D D D #D D
3 UCSB-MOD75 O O O O O O O O
4 UTAH-10 0 O O D D O D O
69 BBN-TENEX D O O O O O O O
133 BBN-TENEXB #D #D #D #D #D #D #D #D
6 MIT-MULTICS O O O O O O O O
70 MIT-DMCG O O O O O O O O
134 MIT-AI H H H H H H H H
194 MIT-ML D D H D H H D H
71 RAND-CSG O D O D O O O O
8 SDC-ADEPT #D #D #D #D #D #D #D D
9 HARVARD-10 O O O O #D #D #D O
10 L.L.-360 H D H D H H H H
74 L.L.-TX-2 R #D O O O #D O O
11 STANFORD-AI D D O O O O D D
14 CMU-10 D O O O O T O O
15 AMES-ILLIAC T O O O D O O O
16 AMES-67 D D D 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.)
F = Full (Destination Host opened a connection, informed user that all
Network ports were in use, and immediately closed the connection.)
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 BBN Corp. under the ]
[ direction of Alex McKenzie. 1/97 ]
AI ELI5
On this page
§1Introduction
RFC 362 reports on host status from June 5 to June 16, 1972. During this period, the MIT Math Lab PDP-10 (Address 198) became a network server. No testing was done on June 6 due to an attempt to install the new IMP system, and no testing occurred on June 9 because the prototype Terminal IMP was being used for software debugging. On June 16, the ARPA Terminal IMP (Address 156) was installed in Arlington, Virginia.
MIT's mathematics researchers got their own computer connected to the network. The ARPANET team continued upgrading the network's core switching systems.
§2Network Expansion
The Terminal IMP count continued growing, with Terminal IMPs at AMES, MITRE, NBS, ETAC, USC, GWC, NOAA, RADC, SAAC, BELVOIR, ARPA, and BBN now excluded from daily testing. The operational server list now included the MIT Math Lab in addition to three other MIT systems (Multics, DM, and AI). This showed MIT's heavy investment in the ARPANET.
The expanding Terminal IMP network allowed smaller organizations and government agencies to connect without maintaining large dedicated computer systems, democratizing ARPANET access.
More and more organizations got Terminal IMPs to connect to the network. MIT had four different computers available to the network now. The network was reaching beyond just the big universities.
§3Host Status and Reliability
The testing results show typical reliability patterns. Most major servers like UCLA, SRI-NIC, UCSB, MIT-Multics, RAND CSG, and Harvard-10 achieved Open status on most days. The new MIT Math Lab server showed significant connection problems (mostly Half Open), as was typical for newly connected systems.
Some machines continued to show persistent failures. AMES-67 and SDC-ADEPT were dead almost every day. SRI-AI, which had been dead for months, remained inaccessible. These chronic failures represented either outdated systems, local site issues, or fundamental incompatibilities with the network.
Most computers worked pretty well. MIT's new computer had some trouble at first connecting. A couple of computers were broken almost the whole time, which had been going on for weeks.