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-   -   "Distance from the Telephone Exchange" Postcode Checker? (https://www.cableforum.uk/board/showthread.php?t=33616075)

grabbi 16-06-2007 17:49

"Distance from the Telephone Exchange" Postcode Checker?
 
Is there a site that calculates the distance and speed you are likely to recieve on a web site?

Im sure Ive seen one, but I cant google it now! :S

pedantic 16-06-2007 18:00

Re: "Distance from the Telephone Exchange" Postcode Checker?
 
Quote:

Originally Posted by grabbi (Post 34329712)
Is there a site that calculates the distance and speed you are likely to recieve on a web site?

Im sure Ive seen one, but I cant google it now! :S

There is a tool here that will tell you your straight line distance, but speed will depend on the condition of your line. If you know your line attenuation and SNR levels, you can use this tool, on the same site.

TheNorm 16-06-2007 18:02

Re: "Distance from the Telephone Exchange" Postcode Checker?
 
This one tells you the distance "as the crow flies":

http://www.dslzoneuk.net/distance.php

Just like pedantic said!

grabbi 16-06-2007 18:23

Re: "Distance from the Telephone Exchange" Postcode Checker?
 
Hey! I watched the Crow last night...

(BTW, WHAT does that mean?) :S

---------- Post added at 19:23 ---------- Previous post was at 19:19 ----------

Well, Hypothetically, if the line was perfect, what speed would it be for 2.2Miles?

It doesnt matter if its below that. Im just wondering what youd get if you paid for "Upto 8Mb"...

TheNorm 16-06-2007 18:25

Re: "Distance from the Telephone Exchange" Postcode Checker?
 
Quote:

Adverb
as the crow flies

(idiomatic) In a straight line distance between two locations, as opposed to the road distance or over land distance.
"It is 15 kilometers as the crow flies."
http://en.wiktionary.org/wiki/as_the_crow_flies

Tezcatlipoca 16-06-2007 19:21

Re: "Distance from the Telephone Exchange" Postcode Checker?
 
Quote:

Originally Posted by grabbi (Post 34329726)
Well, Hypothetically, if the line was perfect, what speed would it be for 2.2Miles?

It doesnt matter if its below that. Im just wondering what youd get if you paid for "Upto 8Mb"...


2.2 miles = 3.54 km


Then, from here:

http://www.skyuser.co.uk/forum/speed...explained.html

(aimed at Sky's LLU, but same principles apply)

"50db...................................3.6km..... ..................................6500kbps"

So, an actual line length of 3.6 km should roughly have a downstream attenuation of 50dB, giving a potential possible max. speed (subject to noise margin) of 6500kbps.

However, your actual line length will be longer than 3.54km, as that's just the straight line distance to the exchange.

grabbi 16-06-2007 19:41

Re: "Distance from the Telephone Exchange" Postcode Checker?
 
Well, 2.2miles was the actual Google Maps thing with directions from earlier on as I searched Google maps site.

So 6500kbps is Basically 6Mb from 8Mb? Thats good stuff! (maximum, I understand.)

Incomplete 16-06-2007 20:06

Re: "Distance from the Telephone Exchange" Postcode Checker?
 
I would multiply that figure by 1.4 to account for indirect cable route.

That gives 4.96km. I think you'd be fortunate to see much above 2Mbit.

TheNorm 17-06-2007 07:41

Re: "Distance from the Telephone Exchange" Postcode Checker?
 
Quote:

Originally Posted by Incomplete (Post 34329798)
I would multiply that figure by 1.4 to account for indirect cable route.....

Don't you find it surprising that they don't publish the actual distances? I'm sure someone has the information.

Incomplete 18-06-2007 07:17

Re: "Distance from the Telephone Exchange" Postcode Checker?
 
BT will certainly have this info but it wouldn't do anything for them bar increase support costs.

AdamD 18-06-2007 12:29

Re: "Distance from the Telephone Exchange" Postcode Checker?
 
You are around 470 metres from your exchange (as the crow flies).
I used to connect at roughly 14/15mb from memory.

christopherw 23-06-2007 10:39

Re: "Distance from the Telephone Exchange" Postcode Checker?
 
Quote:

Originally Posted by Incomplete (Post 34330523)
BT will certainly have this info but it wouldn't do anything for them bar increase support costs.


BT's line test system (17070 from phones) can do a ringback line test to tell you how many metres long your loop length is (local loop from exchange to your phone) but they've locked it off now so only authorised engineers can access it (too many people were using it back in the day to find their line length, then ring up bt and go "YES WE CAN GET IT" when BT were refusing to give them service based on grounds that they were too far away)... Annoying now, but that's the way it is I suppose.

The amount of cable pairs BT have in their network, I wouldn't expect them to keep hard records of line lengths - because by their own admission in the past, lines can go around the houses, take weird and bizarre routes, sometimes two houses' lines might go in opposite directions, all sorts. The network and routing is a complicated mess because most of it's been around for more than 70, 80 years now (I still think some of it's probably pre-1900). Until they rip out every single piece of copper and replace their entire local loop with fresh, new copper, sensibly routed to the nearest cab and dslam, there's almost no point in making and keeping records. Their automated line test facilities (one or more smallish grey boxes installed in every exchange) provide the information that engineers might need on-demand.


I've read things about how if you disconnect one of the two wires inside the master socket then perform the line length test from ANOTHER BT line, specifying your line as the number to check (it has to be a BT line) it may work, though I've not tried it myself as I can't be bothered with the hassle of unwiring and rewiring. Easiest way to find out your loop length is to ask your ISP as they can run the various 17070 tests from their end.


SamKnows.com is the other exchange info site - it's the one I gravitate to most of the time. They also have an exchange checker which shows crow-flies distance from you to your exchange, and seem to have a different set of data upon which they base your location (actual postcode locations as opposed to google's average information) so the distance is probably a bit more accurate.

However, samknows reports me as 1.67km from my exchange straight line, but my line only gives me 10mb on ADSL2+. Based on the Internode graph for ADSL2+ distance-versus-speed graph - http://www.internode.on.net/adsl2/graph/ - a line length of 1.67km should give around 20mb (!) so it's evident that my line length is closer to 3km.

grabbi 25-06-2007 22:00

Re: "Distance from the Telephone Exchange" Postcode Checker?
 
Quote:

Originally Posted by Incomplete (Post 34329798)
I would multiply that figure by 1.4 to account for indirect cable route.

That gives 4.96km. I think you'd be fortunate to see much above 2Mbit.


Is that even with the Roads directions to the Postcode using GoogleMaps?

Ive used that, and that calculates the distance on Foot/in a Car, and isnt in a straight line...

slowcoach 26-06-2007 09:33

Re: "Distance from the Telephone Exchange" Postcode Checker?
 
Only way to find out is to take the plunge, I am 1.93km as Crow and BT couldn't increase my speed beyond 512kB. There are just too many other variables to try to work it out.

ntluser 28-06-2007 06:19

Re: "Distance from the Telephone Exchange" Postcode Checker?
 
Maybe in the future exchanges will broadcast a connection by wireless with a sufficiently strong signal to give all users a superfast service. Don't expect that any time soon.


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