Contact US

Log In

Come Join Us!

Are you a
Computer / IT professional?
Join Tek-Tips Forums!
  • Talk With Other Members
  • Be Notified Of Responses
    To Your Posts
  • Keyword Search
  • One-Click Access To Your
    Favorite Forums
  • Automated Signatures
    On Your Posts
  • Best Of All, It's Free!

*Tek-Tips's functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail.

Posting Guidelines

Promoting, selling, recruiting, coursework and thesis posting is forbidden.

Students Click Here

Have 4 DID trunk lines that shows n

Have 4 DID trunk lines that shows n

Have 4 DID trunk lines that shows n

Have 4 DID trunk lines that shows no activity for almost a month. How do I go about trying to pinpoint what the problem might be?

RE: Have 4 DID trunk lines that shows n

These are analog DID trunk lines?

If you know what public numbers are associated to them, you might try calling them while having a butt set clipped on in parallel, see if hear any digits pulsing in. Honestly wouldn't be a surprise if the phone company shut off the circuit, or accidentally pulled a jumper they thought wasn't active ('no dialtone, must be unused!')

An analog DID line works basically like the reverse of a normal analog line. Instead of the CO providing signalling battery to you, you provide it to the CO. When a DID call comes in, the CO closes the loop (there could be winking involved here, depends on your setup) and once the PBX is ready to receive digits, the CO equipment outpulses them (generally either dialpulse or DTMF, but there could be other options).

To test the equipment on your PBX, it is often enough clip on a buttset or other phone and use the hookswitch to emulate the CO (with winking, where necessary) and dialing digits into the PBX to see if it accepts calls. The PBX generally doesn't provide dialtone on a DID trunk, though you should hear the set click or be able to measure around 48V open circuit if there's talk/signaling battery on the line.

If you're referring to a digital circuit like a T1 or E1, then that's a whole different animal.

Red Flag This Post

Please let us know here why this post is inappropriate. Reasons such as off-topic, duplicates, flames, illegal, vulgar, or students posting their homework.

Red Flag Submitted

Thank you for helping keep Tek-Tips Forums free from inappropriate posts.
The Tek-Tips staff will check this out and take appropriate action.

Reply To This Thread

Posting in the Tek-Tips forums is a member-only feature.

Click Here to join Tek-Tips and talk with other members! Already a Member? Login

Close Box

Join Tek-Tips® Today!

Join your peers on the Internet's largest technical computer professional community.
It's easy to join and it's free.

Here's Why Members Love Tek-Tips Forums:

Register now while it's still free!

Already a member? Close this window and log in.

Join Us             Close