Traffic Stats: Traffic statistics (December 1973)
ARPANET host traffic statistics for December 1973
McKenzie, A.M., "Traffic statistics (December 1973)", RFC 612, DOI 10.17487/RFC0612, January 1974, <https://www.rfc-editor.org/info/rfc612>.
@misc{rfc612,
series = {Request for Comments},
number = 612,
howpublished = {RFC 612},
publisher = {RFC Editor},
doi = {10.17487/RFC0612},
url = {https://www.rfc-editor.org/info/rfc612},
author = {A.M. McKenzie},
title = {{Traffic statistics (December 1973)}},
pagetotal = 6,
year = 1974,
month = jan,
} RFC text
Network Working Group A. McKenzie
RFC # 612 BBN-NET
NIC # 21404 16 January 1974
Updates: RFC # 601
Traffic Statistics (December 1973)
Attached are the Host traffic statistics for the month of December 1973.
AAM/jm
Attach.
HOST THROUGHPUT SUMMARY
(PACKETS OUTPUT)
DECEMBER 1973
INTER- INTRA- AVG. DAILY
NODE NODE TOTAL INTERNODE DAYS
UCLA HOST 0 225002 48819 273821
UCLA HOST 1 1249499 65032 1314531
UCLA HOST 2 92551 2092 94643
-------- -------- --------
1567052 115943 1682995 50550 31
SRI HOST 0 6312552 133362 6445914
SRI HOST 1 451121 176215 627336
SRI HOST 2 10076 11 10087
-------- -------- --------
6773749 309588 7083337 218508 31
UCSB HOST 0 1947716 33249 1980965
UCSB HOST 1 329669 5277 334946
-------- -------- --------
2277385 38526 2315911 73464 31
UTAH HOST 0 1175663 247420 1423083
UTAH HOST 2 172853 143849 316702
-------- -------- --------
1348516 391269 173975 43501 31
BBN HOST 0 1015527 124132 1139659
BBN HOST 1 3682624 94964 3777588
BBN HOST 2 21431 553078 574509
-------- -------- --------
4719582 772174 5491756 152245 31
M-MAC HOST 0 195071 99388 294459
M-MAC HOST 1 1102236 195697 1297933
M-MAC HOST 2 941997 759857 1701854
M-MAC HOST 3 790571 685073 1475644
-------- -------- --------
30298075 1740015 4769090 97738 31
RAND HOST 0 1295314 28072 1323386 41784 31
SDC HAD NO TRAFFIC 31
HARV HOST O 1224055 67910 1903215
HARV HOST 1 794831 590508 1385339
-------- -------- --------
2018886 1269668 3288554 65125 31
LINC HOST 0 31911 9898 41809
LINC HOST 1 62954 57529 120483
LINC HOST 2 6134 10251 16385
-------- -------- --------
1000999 77678 178677 3258 31
STAN HOST 0 1505653 12411 1518064 48569 31
ILL HOST 0 121007 261 1210308
ILL HOST 1 680674 247 680921
ILL HOST 2 716 0 716
-------- -------- --------
1891437 508 1891945 61014 31
CASE HOST 0 1748008 4378 1752386 56387 31
CARN HOST 0 790765 595800 1386565
CARN HOST 1 589699 601150 1190849
-------- -------- --------
1380464 1196950 2577414 44531 31
AMES HOST 0 3389828 3929 3393757
AMES HOST 1 1448 791069 792517
-------- -------- --------
3391276 794998 4186274 109396 31
AMEST HOST 0 147324 23905 171229
AMEST HOST 2 4424439 24660 4449099
-------- -------- --------
4571763 48565 4620328 147476 31
MITRE HOST 2 2374848 42 2374890 76608 31
ROME HOST 2 1292130 56 1292186 41682 31
NBS HOST 2 1994732 4873 1999605 64346 31
ETAC HOST 0 826772 13 826785 26670 31
LLL HOST 0 217895 130632 348527 7029 31
ISI HOST 1 10373770 538733 10912500
ISI HOST 2 2660 94912 97572
-------- -------- --------
10376430 633645 11010080 334724 31
USC HOST 0 162085 2244705 2406790
USC HOST 2 3532401 2118310 5650711
-------- -------- --------
3694486 4363015 8057501 119177 31
GWC HOST 2 2600188 104 2600292 83877 31
DOCB HOST 2 142088 30 142118 4583 31
SDAC HOST 0 156107 4 156111
SDAC HOST 2 803780 87 803867
-------- -------- --------
959887 91 959978 30964 31
BELV HOST 0 1598 33 1631
BELV HOST 1 7 0 7
-------- -------- --------
1605 33 1638 52 31
ARPA HOST 0 33243 288728 321971
ARPA HOST 2 1534869 284722 1819591
-------- -------- --------
1568112 573450 2141562 50584 31
ABER HAD NO TRAFFIC 31
BBN T HOST 0 7481 546752 554233
BBN T HOST 2 590645 263 590908
BBN T HOST 3 354 43 397
-------- -------- --------
598480 547058 1145538 19306 31
CCA HOST 0 969066 1025434 1994500
CCA HOST 2 2046092 738141 2784233
-------- -------- --------
3015158 1763575 4778733 97263 31
XEROX HOST 0 1144892 924507 2069399 36932 31
FNWC HOST 0 21 90 111
FNWC HOST 2 53310 30 53340
-------- -------- --------
53331 120 53451 1720 31
LBL HAD NO TRAFFIC 31
UCSD HOST 0 610793 91339 702132 19703 31
HAW T HOST 0 187 0 187
HAW T HOST 2 442264 87198 529462
HAW T HOST 3 84 4 88
-------- -------- --------
442535 87202 529737 14275 31
RML HOST 2 504141 64 504205 16263 31
NCC-T HOST 0 121 41262 41383
NCC-T HOST 2 2014841 59494 2074335
NCC-T HOST 3 73266 194316 267582
-------- -------- --------
2088228 295072 2383300 67362 31
NORSR HOST 2 58275 45 58320 1880 31
ULOND HOST 0 28311 9321 37632
ULOND HOST 2 747391 58175 805566
-------- -------- --------
775702 67496 843198 25023 31
TYMSH HOST 0 123334 71330 194664
TYMSH HOST 2 47790 68525 116315
-------- -------- --------
171124 139855 310979 5520 31
M-IPC HOST 0 69692 29078 98770 2248 31
MOFF HAD NO TRAFFIC 31
RUTGS HOST 2 617161 22452 639613 19908 31
WRPAT HOST 2 33073 37 33110 1067 31
----------------------------------------
TOTAL 73851720 16474630
DAILY AVERAGE 2382313 531440
AVERAGE PER 52940 11810
NODE-DAY
PACKETS/MESSAGES (INTERNODE) 1.07
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AI ELI5
On this page
§1The ARPANET Traffic Report
RFC 612 is not a specification or protocol definition—it is a data memo from the ARPANET's Network Control Center documenting actual network usage during December 1973. It tabulates traffic generated by each host on the network, measuring the number of packets each host sent during the month.
The ARPANET by this time included hosts at major institutions: UCLA, SRI (Stanford Research Institute), UCSB, University of Utah, BBN (Bolt, Beranek and Newman), MIT, Harvard, Stanford, UC Berkeley (Ames), Xerox, MITRE, Carnegie Mellon, and many others. The report shows traffic from more than 40 network nodes, providing a comprehensive snapshot of network usage.
This paper is a monthly report card for the network. It shows how much traffic each computer sent during December 1973.
§2What the Statistics Reveal
The report categorizes each host's traffic into two types: inter-node traffic (packets sent to other network nodes) and intra-node traffic (packets staying within the local node). This distinction reveals how much of the network was being used for wide-area communication versus local computation and file transfer.
The busiest host in December 1973 was ISI Host 1, which generated 10.9 million packets, with 10.4 million inter-node and 538 thousand intra-node. In comparison, many nodes generated much lighter traffic. For example, BELV Host 0 generated only 1,631 packets total for the entire month. The report shows daily averages, revealing that even high-traffic nodes were only using a fraction of the network's capacity.
The overall network statistics show 73.8 million inter-node packets and 16.5 million intra-node packets for December. On average, the network handled about 2.4 million inter-node packets per day, and the average traffic per node-day was about 52,900 inter-node packets.
Some computers sent a lot of traffic to other computers on the network (inter-node). Some mostly talked to computers right next to them (intra-node). The report shows which computers were busy and which were quiet.
§3Why These Statistics Mattered
Monthly traffic reports were essential for managing the emerging ARPANET. They allowed the Network Control Center and system administrators to identify which nodes were bottlenecks, anticipate when capacity upgrades would be needed, and understand what applications were driving the most network traffic.
The low overall bandwidth usage in December 1973 (measured in packets, not bits, and dominated by local activity) reflects how early the ARPANET was in its development. The network had nowhere near the saturation it would eventually reach. These statistics provided early data about network growth and usage patterns that would inform infrastructure planning in the years to come.
Updates to RFC 612 continued monthly for several years, tracking the growth and evolution of ARPANET traffic through the 1970s. They constitute a valuable historical record of early network usage.
These numbers help the network managers understand what is happening. Is one computer sending way too much? Is a path getting crowded? Do we need to build bigger pipes? The monthly reports answer these questions.