How can I determine distance from exchange?

stockhausen

stockhausen

stockhausen

Capodecina
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I am currently trying to get two users in the same street (about 100 yards apart) set up to work reliably with a particular ISP.

One house gets a download speed of about 10.5Mbps; the other gets about 5.5 Mbps according to www.speedtest.net.

The ISP (devils that they are) claims that the reason the speed is so slow is that I am using a Netgear DG834Gv5 ADSL Modem. This would be more credible if the modems were different - but they aren't and I have used them elsewhere in the past without problem. Added to all of this, the link seems to die periodically without any changes at my end. I am using a microfilter on the only socket available.

Sometime ago, I stumbled across a site (it may have been a BT site) that would provide such details as the distance from the exchange, SNR, Attenuation, etc. - does anyone have any idea what this link might be

From the "slower" site, according to the Modem status screen, I am seeing the following:
Code: 
                              Downstream        Upstream
Connection Speed              6495 kbps         955 kbps
Line Attenuation               40.5 db 	         18.0 db
Noise Margin                   8.65 db           6.0 db


From the "faster" site, according to the Modem status screen, I am seeing the following:
Code: 
                              Downstream        Upstream
Connection Speed             14979 kbps         947 kbps
Line Attenuation               31.0 db 	         12.5 db
Noise Margin                   8.35 db           6.0 db
 
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What your findings suggest then, is that the distance from the exchange is not the limiting factor in speed for the slower place, and thus something else is causing it.

I know when I originally got BB, the line from the house to the lines on the street had to be replaced by BT to allow the connection as it wasn't good enough. Also, the box down the street has been tinkered with on several occasions when we were suffering dropouts, so it could be something there too. The house is from the 70's and nothing had been replaced since until then.
 
The slower connection clearly has a higher attenuation (40.5dB vs 31dB) which means the line length is longer or it is of poorer quality. This is why distance from the exchange doesn't really matter at all as there are so many factors in between which you have no control over.

If there is no extension wiring then there isn't really a great deal you can do about it.
 
Are they both fed off the same distribution point? if not one line could contain alluminium cable lengths which would cause a higher attenuation etc. It really isnt as clear cut as "Oh i should get the same speed as my next door neighbour or the bloke down the street" i'm afraid.
 
If the telephone points are 100 yards apart then there should be little difference in Line Attenuation... Have you typed in both numbers into the O2 website? do they say they should get the same speed?
 
I have just checked my stats at home, they are:
Code: 
                              Downstream        Upstream
Connection Speed             10697 kbps        1181 kbps
Line Attenuation               31.0 db 	         7.0 db
Noise Margin                   3.95 db           7.0 db
Download speed according to SpeedTest.net is 9,200kbps. I can't believe that the downstream SNR can be so low, that's insane; probably time to have a word with BT :eek:
 
stockhausen said:
I am currently trying to get two users in the same street (about 100 yards apart) set up to work reliably with a particular ISP.

One house gets a download speed of about 10.5Mbps; the other gets about 5.5 Mbps according to www.speedtest.net.

The ISP (devils that they are) claims that the reason the speed is so slow is that I am using a Netgear DG834Gv5 ADSL Modem. This would be more credible if the modems were different - but they aren't and I have used them elsewhere in the past without problem. Added to all of this, the link seems to die periodically without any changes at my end. I am using a microfilter on the only socket available.
Click to expand...


It could be as simple as the house that is further away has a line (or even wiring) of particularly physically bad quality compared to everyone else... therefore signal sucks even compared to houses just a stones throw away.
 
You say modems, plural, but only list one, what's the other? Oh and remember that attenuation is not your distance from the exchange, it's a measure of resistance on the line. The only way to actually get your line length is to dial 17070 and choose the distance test (ping? idk) but that's been locked to bt engineers for a couple years now. You can still do the quiet line test though.
 
Distance is a factor but isnt the only one :/

Two homes could have the same length of phone line but very different stats because of varying quality in the line and its connections.
 
I read on somewhere else that BT can tell you over the phone the exact length you are from the exchange & not just a straight line distance estimate that samknows tells you?

Liam
 
stockhausen said:
All modems are Netgear DG834G v5. I also have access to some Thomson (BeBox) job and will experiment with that.

What's the "quiet test"?
Click to expand...

Its just to test for any audible noise on the line. It takes the dial tone off and has a woman say "quiet line test" every 15 seconds or so.
 
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