(E-Mail Removed) wrote in message
(E-Mail Removed):
> On 14-Nov-2006, "Martin Underwood" <a@b> wrote:
>
>> The dialling tone sounded mushy compared with another
>> non-broadbanded phone line; the customer also reported that the
>> broadbanded line had experienced problems sending/receiving faxes -
>> sounds like there's a wiring fault somewhere between his socket and
>> the exchange.
>
> You don't say how far he is from the exchange, give or take a bit, as
> it's rarely the most direct route.
The exchange is reported by BT's line test as being Nuneham Courtenay
(Oxfordshire) and the customer lives in Dorchester, about 5.8 km as the crow
flies. Given that this is quite a high figure, I'm wondering whether there
might be another "repeater" exchange closer to him. Or is 5.8 km not
excessive these days?
> Or whether he has any neighbours with a good connection.
The person who lives opposite him (coincidentally, another of my customers)
can get a good broadband signal. I set them up with a Netgear router about 6
months ago and they were getting (I think) 2 Mbps down / 488 Kbps up - I
remember the upload speed because it was the first time I'd ever encountered
upload speed greater than 288 - so the exchange has been upgraded to ADSL2.
> Has he, or can he borrow, a dialup PSTN modem, what speed
> does it connect at?
I noticed that his PC's built-in dial-up modem was achieving 49 kbps when I
tried it yesterday - ironic that a line which gives an unusually high
dial-up speed should be so poor for broadband. I couldn't test the broadband
state yesterday because Wanadoo ceased ADSL on the line ages ago when they
cancelled the contract. Checking back in my records, I first became involved
in June 2005 (yes, over a year ago!) and we faffed around with Wanadoo for a
couple of months, at which time he said he was going to try a different ISP.
I didn't hear anything since then until a year later when he called me in
yesterday about a problem with his dial-up modem crashing his PC (needed a
System Restore to a previous day's config) and he mentioned about trying
again now for broadband.
> Many of the USRobotics Courier modems
> give a wealth of line statistics and the lines frequency response
> figures, which you can then plot, to see it's rolloff at the upper
> end of the audio frequency band.
> There are several possible causes and regardless of which ISP he
> chooses any line problem needs to be fixed if he is going to get a
> reliable service.
> What has to be determined is whether line length, bad connection
> (dry joint), water in the underground cable, split pair, bad dropwire,
> noise from adjacent cables and services (street lighting and MV
> ring main cables may be running parallel for some distance) or
> whatever. BT has test sets that will fully characterise a line and
> it's
> problems, plot the frequency response, measure noise, gain
> (attenuation) and phase hits. Even do a bit error rate test.
> It's getting them to use them that's the problem, it's only a
> pair of wires from A to B and it's not rocket science to test
> them. There are also Reflectometers that will measure the
> distance to faults, indicate their nature (water, dry joint,
> open/short circuit) so the pick and shovel brigade know where to dig.
> I've used them, you would think BT had never heard of them.
I presume most of these tests have to be carried out from the customer's
master socket, and that there's a limit to the faults that can be diagnosed
from the exchange end.