Network Working Group J. Heafner
Request for Comments: 227 E. Harslem
NIC: 7631 September 17, 1971
Updates: RFC 113
 DATA TRANSFER RATES (RAND/UCLA)
 The attached memo indicates data rates typical of our use of RJS at
 UCLA CCN. Earlier timing tests (similar but more detailed) with UCSB
 showed that most of the time was lost because of: (1) channel
 contention with our disk drive access; (2) our NCP runs at a higher
 priority than batch jobs but lower than text editing and interactive
 graphics; (3) OS interrupt handling is very slow on both ends; (4)
 spooling time of the remote system.
 MEMORANDUM
TO: John Heafner
FROM: Bob Hoffman
COPIES: Bob Mobley, Herb Shukiar
Here are some of the transmission rates I have noted over the network
between Rand and UCLA. These were all taken at night when little else
was happening on our 65.
SEND TO UCLA
 # Cards Blocksize (bytes) Time (secs) Rate (bits/secs)
 642 80 50 8218
 375 80 30 8000
 509 800 20 16288
RECEIVE FROM UCLA
 For all figures below, the receiving file has blocksize of 1330
 bytes, and each line is assumed to contain 100 bytes. This last
 assumption is fairly accurate, since most of the lines were from PL/I
 for which this is a very good number. Thus, for each rate, the
 number of bytes is the # Lines * 100.
 # Lines Time (secs) Rate (bits/secs)
 4900 200 19600
 872 47 14843
 3900 185 16865
 As you can see from the send figures, blocking makes about a 2:1
 difference. Memory also recalls a 2 or 3 to 1 advantage for blocking
 on receive when we were getting unblocked files from UCSB.
 REH:gb
 [This RFC was put into machine readable form for entry]
 [into the online RFC archives by Kelly Tardif, Viagénie 10/99]