Network Host Status
Checking which network hosts were working in late June 1972
Westheimer, E., "Network Host Status", RFC 366, DOI 10.17487/RFC0366, July 1972, <https://www.rfc-editor.org/info/rfc366>.
@misc{rfc366,
series = {Request for Comments},
number = 366,
howpublished = {RFC 366},
publisher = {RFC Editor},
doi = {10.17487/RFC0366},
url = {https://www.rfc-editor.org/info/rfc366},
author = {E. Westheimer},
title = {{Network Host Status}},
pagetotal = 4,
year = 1972,
month = jul,
} RFC text
Network Working Group Ellen Westheimer
NIC # 11013 BBN
RFC # 366 11 July 1972
Categories: F. G.3
Updates: RFC #362
Obsoletes: None
NETWORK HOST STATUS
This RFC reports on the status of most Network Hosts from June 19
to June 30.
No testing was done on June 20 due to an attempt to install the
new IMP system.
Several Hosts are currently excluded from the daily testing as
they are presently intended to be users only. Included here are the
Terminal IMPs, which are presently in the Network (AMES, MITRE, RADC,
NBS, ETAC, USC, GWC, NOAA, SAAC, 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
138 Lincoln TSP
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.
NO. SITE DATE AND TIME (EASTERN)
--- ---- -----------------------
6/19 6/21 6/22 6/23 6/26 6/27 6/28 6/29 6/30
1700 1830 1530 1300 1600 1400 1400 1600 1530
1 UCLA-NMC O O O O O D H O O
65 UCLA-CCN* O O O T O O O O O
2 SRI-ARC O O O O D O O D D
66 SRI-AI D D D D D D #D D O
3 UCSB-MOD75 O O O O O O O O O
4 UTAH-10 O O O D O O D H D
69 BBN-TENEX O O O T O O O F O
133 BBN-TENEXB #D #D #D #D #D #D #D #D #D
6 MIT-MULTICS O D O O O O O O D
70 MIT-DMCG O F O O O F H O O
134 MIT-AI H H H O O O O O O
194 MIT-ML H H H O H H D H H
71 RAND-CSG O O O H O D O O O
8 SDC-ADEPT D D #D #D D #D #D D #D
9 HARVARD-10 #D #D O O O O O O O
10 L.L.-360 H T H H H T H H H
74 L.L.-TX-2 T O R D O O #D O O
11 STANFORD-AI O O O O O O O T O
13 CASE D D D D D D D D D
14 CMU-10 O O O O O O D D O
15 AMES-ILLIAC O O O O O D O O T
16 AMES-67 D D D D D D D D D
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.
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) PDP10 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 Server 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
*138 LINCOLN TSP User Only Tom Barkelow
11 STANFORD PDP-10 Server Andy Moorer
*12 ILLINOIS PDP-11 User Only John Cravits
13 CASE PDP-10 July 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.
[ 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 ]
9
AI ELI5
On this page
§1Introduction
RFC 366 reports on host status from June 19 to June 30, 1972. By this time, the ARPANET had matured significantly since its founding five years earlier. No testing was done on June 20 due to an attempt to install the new IMP system. This report represents the final piece of the early host status survey series, documenting the network's state at the end of June 1972.
This report shows how the ARPANET was doing near the end of June 1972. The network was now well established, with regular operations across many sites.
§2Network Structure
By June 30, 1972, the user-only hosts excluded from testing included Terminal IMPs at AMES, MITRE, RADC, NBS, ETAC, USC, GWC, NOAA, SAAC, ARPA, and BBN, plus the Network Control Center (Address 5). The operational servers included UCLA, SRI (two sites), UCSB, UTAH, MIT (four sites), RAND, SDC, Harvard, Lincoln (two sites), Stanford, Case (which had become a server in late June), Carnegie, and AMES.
This represented a comprehensive distributed computing network, with multiple sites offering different services and capabilities to ARPANET users nationwide.
The network now had many different computers in different cities all working together. Some were just connection points (Terminal IMPs), while others offered services that other people could use.
§3Network Status and Performance
The testing shows predominantly Open status for most operational servers. UCLA, UCSB, MIT-Multics, MIT-DM, MIT-AI, MIT-ML, RAND, Harvard, Stanford, Carnegie, and AMES-ILLIAC frequently achieved Open status, indicating reliable connectivity. Some hosts like SRI-AI remained persistently dead or problematic.
The network showed the stability expected of an operational system after five years of development. Temporary failures occurred, but the core infrastructure was sound. The ARPANET had transitioned from an experimental network to an operational resource serving the research community.
Most computers were working pretty well by the end of June. A few still had problems, but overall the network was reliable and useful for research.