Strange behavior from network

[aram535]

I ran into a slight problem at home, I was playing with shoutcast and shout to broadcast 64 bit music through my network. And it keeps breaking up, and that the connection seems to be dying a little too easily.

The Linux box was the broadcaster, and the XP or the 2000 boxes the player so I did the following tests, and here is the results:

setup I have at home:

Cisco 2924XL - 12.0(5)WC2b
w/ all ports locked to speeds specified, nothing on autoneg.

I am transferring a 16MB file back and forth using ftp for transfer tests and the following are the results.

The -> points the direction the data is travelling not who initiated the transfer:

Cable -> Linux @ 510.1 kb/sec [ 100/F ]
Cable -> 2000 @ 773.2 kb/sec [ 100/F ]
2000 -> Linux @ 51.7 kb/sec [ 100/F ]
Linux -> 2000 @ 338.10 kb/sec [ 100/F ]
XP -> Linux @ 741.0 kb/sec [ 10/F ]
Linux -> XP @ 533.4 kb/sec [ 10/F ]
T21 -> Linux @ 579.7 kb/sec [ 10/F ]
Linux -> T21 @ 400.1 kb/sec [ 10/F ]

Cable is OptimumOnline @ 100MB/Full
WAP is Linksys WAP11 @ 10MB/Full
2000 is a Windows 2000 Pro AMD Athleon 1.2Ghz
w/ Netgear FA312 card locked at 100MB/Full
Linux is a Redhat Linux 7.3 Pentium 4 2.0 Ghz
w/ Intel Etherpro 100 82557 chip at 100MB/Full
XP is a Windows XP IBM i1401 Laptop with a PII-226
w/ 3C589D at 10MB/Full
T21 is a Windows 2000 IBM T21 laptop with a PIII-600
w/ Lucent Orinoco w/Excellent Radio connection

* There is plenty of memory on all systems (except XP - 128MB)

[Greenstead]

I am going to join you here. Not because I know the answers to this problem but because I would like to understand this issue more and I look forward to any knowledgable reponses from others.

It is quite common to see people post their dissapointment with network throughput vs the NIC nominal bit rates. I have done similar tests on my network and get low throputs. There is a tester here you can use:
http://www.netiq.com/qcheck/default.asp

I think there are two issues here:
1. The actual average flow rate vs the ratings of the network interfaces. (Not really a problem as long as the rate is reasonable)
2. Maintaining a smooth flow rate necessary for multimedia. e.g. audio or video. (a serious problem if what you see or hear is slow or disjointed).

Its interesting that you (and I too) get such different rates between two interfaces dependent on which way the data is being moved.

What I know:
- Obviously bad connections or interference (causing errors) will effect the data flow. Check all connections are solid, cables are good quality and not near mains cables.
- Flow rate depends on protocol. i.e. TCP vs UDP. I would assume UDP is necessary for broadcasting audio or video.
- There is a known problem with some 100Mb interface cards due to the interframe spacing which can causes errors. Adjustment is possible to improve this.
See more on this here:
http://support.microsoft.com/default.aspx?scid=kb;en-us;Q315237
http://support.microsoft.com/default.aspx?scid=kb;en-us;Q169789
- It is possible to influence things by changing some of the communication parameters in the registry but it should be noted systems such as XP are meant to be 'self-tuning' and manual changes should not be necessary.

Anyone know more - please say so.