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ISDN connection problem!!!

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KCTC

Technical User
Apr 23, 2005
6
GB
I moved an ISDN line and now for some reason this does not work. There is a weird tone but no dial tone. Does not receive or able to make calls. This has just been re wired from one floor to another and wiring has been double checked. BT have said all OK. Any ideas on what I can try? Thanks.
 
Since you mention BTY I am assuming you are in the UK. IN that case it is likely the Telco rovided the NTBA (NT1) and you are working with the S interface.

The S interface has limits in terms of both Distance and termination. If you previous jack was close to the NTBA then the termination was not required.

With the greater distance termination is probably required. You should try an in line termination resistor near the phone and see if that helps.

What is the total distance from the NTBA to the Phone?

Good luck.
 
Could not tell you the exact distance but it has moved down one floor. Never come across one of these before but will do some digging. Many thanks for your help.
 
Is there just one phone on this S bus, or multiple phones?

The termination requirements vary depending on how many phones and how they are located. However a general rule is that the phone furthest from the NTBA must be terminated. Perhaps that used to be some other phone, but now it is the phone that has been moved. In that case you would be moving the termination resisitor.

BT should have detailed information on this on their web site, but any good ISDN reference also covers this.

Here's a BT link:

 
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