Traffic statistics (December 1972)
The ARPANET's usage statistics showing traffic across all connected systems in December 1972.
McKenzie, A.M., "Traffic statistics (December 1972)", RFC 443, DOI 10.17487/RFC0443, January 1973, <https://www.rfc-editor.org/info/rfc443>.
@misc{rfc443,
series = {Request for Comments},
number = 443,
howpublished = {RFC 443},
publisher = {RFC Editor},
doi = {10.17487/RFC0443},
url = {https://www.rfc-editor.org/info/rfc443},
author = {A.M. McKenzie},
title = {{Traffic statistics (December 1972)}},
pagetotal = 3,
year = 1973,
month = jan,
} RFC text
Network Working Group A. McKenzie Request for Comments: 443 BBN NIC: 13899 18 January 1973 Updates: RFC 422 Traffic Statistics (December 1972) Attached are the Host traffic statistics for the month of December 1972. AAM/jm HOST THROUGHPUT SUMMARY (PACKETS OUTPUT) DECEMBER 1972 MISSING DATA FOR 2, 3, 4, 8, 15, 20 INTER- INTRA- AVG. DAILY NODE NODE TOTAL INTERNODE DAYS UCLA HOST 1 181141 57162 238303 UCLA HOST 2 668578 44616 713194 -------- -------- -------- 849719 101778 951497 33989 25 SRI HOST 1 1396436 17556 1413992 SRI HOST 2 31365 3836 35201 -------- -------- -------- 1427801 21392 1449193 57112 25 UCSB HOST 1 545166 173928 719094 21807 25 UTAH HOST 1 536453 35616 572069 21458 25 BBN HOST 2 2424250 373106 2797356 BBN HOST 3 108384 29878 138262 BBN HOST 4 153239 37 153276 -------- -------- -------- 2685873 403021 3088894 107435 25 MIT HOST 1 48752 13998 62740 MIT HOST 2 482445 224148 706593 MIT HOST 3 401599 373678 775277 MIT HOST 4 201840 439670 641510 -------- -------- -------- 1134636 1051484 2186120 45385 25 RAND HOST 1 264812 86 264898 10592 25 SDC HOST 1 27964 4416 32380 1119 25 HARV HOST 1 299236 397614 696850 HARV HOST 2 23247 315178 338425 -------- -------- -------- 322483 712792 1035275 12899 25 LINC HOST 1 10158 1104 11262 LINC HOST 2 28589 67907 96496 LINC HOST 3 578 4512 5090 -------- -------- -------- 39325 73523 112848 1573 25 STAN HOST 1 1015835 13196 1029031 40633 25 ILL HOST 1 386634 280 386914 15465 25 CASE HOST 1 221014 28570 249584 8841 25 CARN HOST 1 317017 217871 534888 CARN HOST 2 265575 193101 458676 -------- -------- -------- 582592 410972 993564 23304 25 AMES2 HOST 1 2811857 28592 2840449 112474 25 AMES1 HOST 1 57368 14650 72018 AMES1 HOST 3 4384317 18336 4402653 -------- -------- -------- 4441685 32986 4474671 177667 25 MITRE HOST 3 1091812 51 1091863 43672 25 ROME HOST 3 487923 25 487948 19517 25 NBS HOST 1 738 24 762 NBS HOST 3 921496 92 921588 -------- -------- -------- 922234 116 922350 36889 25 ETAC HOST 3 878406 416 878822 35136 25 TINK HAD NO TRAFFIC ISI HOST 2 4176170 46977 4223147 167047 25 USC HOST 1 13611 151120 164731 USC HOST 3 922350 146673 1069023 -------- -------- -------- 935961 297793 1233754 37438 25 GWC HOST 3 15327 76 15403 613 25 NOAA HOST 3 58916 29885 88801 2357 25 SAAC HOST 3 209321 538 209859 8373 25 BELV HAD NO TRAFFIC ARPA HOST 1 0 180178 180178 ARPA HOST 3 155445 177439 332884 -------- -------- -------- 155445 357617 513062 6218 25 ABER HAD NO TRAFFIC BBN T HOST 3 640257 3939 644196 25610 25 CCA HOST 1 383002 318035 701037 CCA HOST 3 875814 148241 1024055 -------- -------- -------- 1258816 466276 1725092 50353 25 XEROX HAD NO TRAFFIC UCSD HOST 1 328825 4186 333011 13153 25 HAW T HOST 3 36487 38789 75270 3317 11 ------------------------------------ TOTAL 28489750 4339316 DAILY AVERAGE 1139590 173573 AVERAGE PER 34079 5191 NODE-DAY PACKETS/MESSAGES (INTERNODE) 1.06 [ This RFC was put into machine readable form for entry ] [ into the online RFC archives by George Bauer 11/97 ]
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§1Network Traffic Statistics
RFC 443 presents the ARPANET's host traffic statistics for December 1972, compiled and published by BBN. The report shows how much data each connected host was transmitting, measured in packets. The data is presented in a table format showing each site and its hosts, with columns for inter-node traffic (packets sent to other sites), intra-node traffic (packets sent locally), and daily averages.
This was a regular monthly report that the community relied on to track network usage and understand which sites and applications were most active.
A monthly scorecard showing how busy each computer was on the network.
§2The Data
The report includes traffic data from about 25 sites connected to the ARPANET in December 1972, including UCLA, Stanford Research Institute, UCSB, University of Utah, BBN, MIT, Rand, Harvard, MIT Lincoln Labs, Stanford, University of Illinois, Carnegie Mellon, NASA Ames, and others. Some nodes had no traffic, either because they were inactive or not yet connected.
The top traffic generators included Ames Research Center, ISI, BBN, Stanford, and MIT. The total inter-node traffic for the month exceeded 28 million packets, with a daily average of about 1.1 million packets, or about 34,000 packets per node per day. The report notes that some days of data were missing due to collection problems.
The biggest computers sending messages were at space agencies and research labs. The whole network sent tens of millions of messages in one month.
§3A Snapshot of Early ARPANET Usage
These statistics capture the ARPANET at a specific moment in its growth, about four years after the first IMP installation. The data reveals which sites were most active participants and shows the relative balance of traffic across different types of institutions. The distinction between inter-node and intra-node traffic indicates that many sites had multiple hosts and generated significant local traffic.
Regular publication of these reports became an important part of network management, providing the community with visibility into how the network was being used and helping coordinate growth and upgrades.
This shows what the early network looked like in December 1972, which computers were busy, and how much they were talking to each other.