atcomsystems.ca/forum Forums Wiring - Telecom Carriers - Trunks & Services Telecom Service & Providers DID lines

If I put a buttset on a dry DID trunk and call the # will it ring my phone or do you need power supplied on the line?

If you connect to the trunk port on the switch, then no you do not need to supply power. The DID trunk port sends power toward the CO. You just go off-hook and dial the DID digits into the switch.

Also on a DID trunk doesn't the premise equipment (customer) supply the voltage battery for the lines? If not what is the voltage suppose to be, will it be typical battery 48Vdc.

That is just it, we are trying to test the DID trunk for static and need to seperate the equipment from the trunks to test. Any suggestions on the best way to test or trouble shoot DID trunks.

Yes, the CPE supplies the -48 volts DC toward the CO. When going off-hook, you will hear the click from the "wink" being sent, then just dead air. That's when you dial the DID digits.

I really appreciate your help ED.

Disconnect the pair at the network interface, not at the switch and dial your test calls from there. If no static is heard, then the static is coming from the telco's cable pair. Those are tough to prove, but since DID trunks are generally considered to be special services circuits, the telco usually has better-trained technicians to troubleshoot these.

Ed,

What would you do to test these trunks for static or a humm?

Ok, so what you mean is disconnect and call into the CPE, with the four digits?

Yes, simply go off hook, hear the wink click and dial the four digits. As far as any further testing, there would have to be a telco technician on-site with test equipment to test the cable pair for static from the CO. Doing the testing we have discussed with a butt set is really all the testing that you can do.