Luminous

iTrader: (3)

I am just wondering how this actually reports speeds. On a 100Mbps network, is 100% utilization really 200Mbps duplex? Therefore, if you are just sending information to a computer you cannot actually expect it to report much more than 50% utilization?

I only ask as I have been fiddling around with the network, and upgraded part of it to Gigabit today. Transfer rates seem to be able half of what I would expect, hence my question about duplex.

LostUser

I've also seen the networking tab report a consistent 50% but didn't really think much of it.

If you want actual figures rather than percentages I'd use another tool to monitor the transfer rates. I know Network Monitor that comes with W2K3 does this but I've haven't used it much. The new version 3 might be better.

What part of the network is it you've upgraded? I assume the machine you're testing against now has a gigabit connection? Is the network card set to auto or hard coded to a speed and duplex?

Luminous

iTrader: (3)

I upgraded my machine and all switches to Gigabit. Then connected to a NAS drive that was gigabit enabled. My computer reports 1000Mbps (full duplex) according to my network card, the NAS drive reports the same on its setup menu. During data transfers max utilization I have seen is 15% (so definitely more than before).

Previously network utilization has rarely been above 50%, which I find strange unless this duplex thing is coming into play.

I did a little more poking around and found that you can add columns for send and receive utilization. When receiving data from the NAS drive, receive was 15%, send was less than 1%, total was still 15%. So my theory of the duplex potential to alter the readings does not hold water

Sonic'

IIRC

Windows doesnt run at proper Gigabit

and Window 2003 Server didnt either until you put service pack 2 on it

Apparently, and I do stand to be corrected, is that when a connection with another device is established (ie a file transfer etc) it negotiates a speed (not necessarily gigabit, might be 300kb/s etc etc, Windows would then stick at that speed for all communication for 60 minutes, then reset

SP2 for Win 2k3 supposedly fixed this issue

Sonic'

Oh, and see if you can get Ixia Chariot, its very very good for testing end to end network speed and can simulate a rather vast array of network traffic

It is not cheap though, starts at 5k for a 10 node license


We have just used it to prove Easynet are a sack of cow dung, and gathered enough evidence to terminate a 50k contract

unfeasablylargegonads

iTrader: (3)

few tips

iperf, smoke ping + other opensource stuff are good for testing/tunning for free. Make sure you have the RFC1323 bells/whistles enabled (have a look at http://support.microsoft.com/kb/224829).

super_si

Are you running auto speed/ duplex? ive found speed's alot lower during the continual negotiation.

S

Luminous

iTrader: (3)

*ducks* Oh look, nearly all of that went over my head


I am running cables from the back of my machine into switches and stuff The knowledge base article linked above comes up "page not available". I'll try and read around this, but I have not really looked into networking before. I just plug stuff in and make sure the correct speed rating lights come up on switches/hubs/ etc