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Data transfer rates (Rand/UCLA) (RFC0227)

IP.com Disclosure Number: IPCOM000002830D
Original Publication Date: 1971-Sep-17
Included in the Prior Art Database: 2000-Sep-13
Document File: 1 page(s) / 2K

Publishing Venue

Internet Society Requests For Comment (RFCs)

Related People

J.F. Heafner: AUTHOR [+2]

Abstract

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.

This text was extracted from a ASCII Text document.
This is the abbreviated version, containing approximately 100% of the total text.

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]