BT Voyager 105 + Skype

[Mauldor]

The Background
I know this is not a NTL Question but I thought I might ask if anyone has come across such a thing as its puzzling me tbh. Now the background, I am on NTL Cable modem (Sb4100) connected via a router (rj45) to a swtich to my machines. My Mate though went for a Bt ADSL Connection and got supplied with a BT Voyager 105 USb Modem. He only has one machine, a Laptop and modem plugs into that.
Specs for his laptop btw are P4 3.06Ghz, 512 meg ram, GeForce5600 64Meg ram.

The Problem
If he is talking on Skype (voice chat s/w) to me and he then tries to play a online game (MOHAA) he lags in game. If say he starts downloading a file while we are chatting skype has a mega delay (5-10 secs maybe) and his voice breaks up. The second he stops downloading Skype returns to normal. If he plays games without doing anything else network wise (even checking email) then he is fine.

Further Tests
When He came over to my house at Xmas time, he connected his laptop to my network, were were both only both in Skype chatting to someone else but also playng various online games without a single problem with any lag whatsoever. I checked and re-checked his machine for Virus, Spyware etc.

What I am trying to work out is this basically, is the problem to do with USB Modem (he has or thinks he has latest drivers) - does anyone who ran on USB NTL CM have these probelms? Is the problem maybe with BT?

Why do i find this odd?
If i am talking on Skype myself it takes up 4k and download or upload can only take what is left - in the case of Uploads (im on 750/128) - this uploads at 9-10k. Taking 4k away from a 512 or 750 connection should not really impact it that much and it does not with me. Does USB have a feature that sucks up all the bandwidth no matter what?

I am def betting on the USB side of life tbh - I have advised him to get a Wireless ADSL router (he has wireless already built into laptop) and also when April comes and his 12 months are up - move away from BT. Anybody any insight why his rig does all of the above?

[Aragorn]

Mauldor,

I would probably get your friend to do some tests with something like dumeter or netmeter.

Get them to use just Skype with a bandwidth meter running in the background, and then do some online gaming and maybe some file transfer without Skype. This should allow you to see how much traffic his USB modem can handle and what percentage of the maximum is being used by Skype. As you will probably have seen, most NTL/Telewest BB users will use RJ45 in preference to USB because of the performance problems that USB can give, so he may well not be getting his full 512Kb through that USB modem.

Another thing to consider - is he using any other USB devices with Skype, eg USB headset, speakers, mike, that might be slowing down USB.

HTH

[Mauldor]

Well Skype uses about 4k - He has Netpeeker running and it shows what uses what. I think there must be USB problem with downloads cos As I say if he start a download lets say - Skype goes down to 1k and the download uses most if not all the connection - thus why skype goes bad. Odd that it has the oppisite effect on say gaming but maybe the traffic is prioity on TCP over UDP maybe (Im guessing a game uses UDP?).

Now you come to mention it - he has USB speakers plugged in as well as USB modem. I'll inform him to buy like yesterday a Network capable ADSL modem to see if that stops the problem - thanks for the reply