Path: utzoo!utgpu!news-server.csri.toronto.edu!rutgers!ucsd!ucbvax!BU-IT.BU.EDU!kwe
From: kwe@BU-IT.BU.EDU (Kent England)
Newsgroups: comp.protocols.tcp-ip
Subject: Re: bandwidth usage for X applications?
Message-ID: <9103111739.AA03163@buit13.bu.edu>
Date: 11 Mar 91 17:39:26 GMT
Sender: daemon@ucbvax.BERKELEY.EDU
Organization: The Internet
Lines: 71


	Some people here in Information Technology at Boston
University set up a test to measure network load from one X terminal
doing specific X things.  Here is an excerpt of what they did:


       +------------+                      +--------------+
       |            |                      |              |
       | diskful    |                      | Visual       |
       | server     |                      |              |
       |            |                      | X19 turbo    |
       |            |                      |              |
       +------------+                      +--------------+
             ||                                   ||
   =================================================================
                                ||
       subnet            +--------------+
                         |              |
                         | LANalyzer    |
                         |              |
                         +--------------+


	They ran some test cases for a variety of X terminal
activities.  The only traffic on the network was traffic from the X
terminal and the diskful server, including all X traffic and some NFS
traffic for diskless font service on the X terminal.  The window
manager, twm, was running on the diskful server and not on the X
server.  All X clients are running on the diskful server.

	TEST		pkts/sec		kBytes/sec

	maze		425			30
	xterm tftpboot	303			92
	twm:
	  move win	220			18
	  resize	220			18
	  hold button	220			18
	plaid		220			17
	ico		67			12
	xbench		50			20
 2 xtermwins cat'ing	45			23
	xclock		0.0166-1		~~
	move mouse
	 out of win	3-5 pkts		~~


	These numbers from the LANalyzer measure Ethernet frame data;
source and destination MAC addresses, protocol type field, user data
payload and CRC, but do not include the preamble or interframe gap.

	For reference purposes, Ethernet at 10Mbit/sec can transfer
about 1,000 kBytes/sec of Ethernet data in maximum sized frames, after
subtracting the preamble and minimum interframe gap times.  The
maximum number of Ethernet frames per second, assuming minimum sized
legal frames, is 14,880 frames/second.

	These tests do not factor in the presence of routers between
the X terminal and server, nor do they account for the diskful server
load, given that the diskful server is bootloading, running all window
managers and all X client processes and all processes under the
clients (such as shells).  These tests do not measure actual usage
patterns.

--------------------------------------

	Those who really did the work:

	Mike Amirault (ambi@bu-it.bu.edu)
	Jason Heirtzler (jdh@bu-pub.bu.edu)
	Chuck von Lichtenberg (chuckles@bu-it.bu.edu)