[Sderby] ADSL Problems - gah!

[Kris and Laura Adcock]

(I've posted this on ADSL-related newsgroups, but not had any replies. 
Thinking about it, though, I reckon I'd probably get more 
technically-minded answers here.)

Right,

I am trying to set up Broadband access for the office of a small 
church/charity. The exchange has been switched over, the Zoom x3 
Ethernet modem is up and running, and I have my laptop connected to it. 
The modem's log shows that things are positive - IP address assigned, 
netmask, DNS and gateway settings are all fine.

However ...

If I leave Linux pinging an arbitrary address and then stop after a 
minute or so, it informs me that 5-10% of packets have been lost. 
Webpages refuse to transfer - the browser informs me that it has found 
the site, then just stops. I can telnet to an NTP server and get the 
time fine. If I ftp over to an ftp site, things go fine until I actually 
try and transfer a file, or if text of a substantial quantity needs to 
be transferred (so 'ls' tends to work, but 'ls -al' screws up). 
Basically, any transfer of any real quantity tends to grind to a halt.

Now, this is the second modem. I took the first one back to the shop 
because I believed the modem had a 'dodgy-buffer', or something. But as 
the new one has exactly the same symptoms, I'm thinking that the fault 
is elsewhere.

So, has anyone else had this problem? How did you fix it? It could be 
possible that there's a setting in the modem which limits bandwidth, but 
I don't think that's where the fault lies. Who should I be talking to to 
faultfind this situation?

Now, I've had some very unproductive telephone calls with freenetname's 
supposed 'technical support', who basically charged me 50p per minute to 
be put on hold and then refused to help me. To confuse matters further, 
freenetname's ADSL access is provided by a company called Bulldog DSL. 
But it turns out that Bulldog are really only the admin side, and 
actually the service is being provided by BT. So I just KNOW that 
whoever I ring will blame one of the other parties ... and so on, until 
the end of time.

Originally I was using a Windows ME laptop, but after the tech-support 
tried to fob me of with "blah blah MTU sizes blah blah" I've installed 
Smoothwall 'twixt the two. No difference, but then I didn't think there 
would be.

Sigh ...

Cheers, and thanks for any help in advance,

Kris.