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Have 4 DID trunk lines that shows n
- Thread starter Dbrowne1
- Start date
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.
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.
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