sundance-communications.com/forum Forums Other TDM Phone Systems 1A2 and Comkey Telephones & Systems Voip

I would like to feed one of the lines on a what I think is a 551B KSU with Voip. Please share your experience and thoughts with me. Thanks!

As long as the VOIP equipment sends a loop supervision disconnect when the calling party hangs up, you won't have any problems. 1A2 equipment is very forgiving and tolerant of most issues.

Welcome aboard, Murray. You've found the right place for answers.

Thanks Ed I was concerned about the 1A2 damaging the VOIP gear. all the providers seem adament about using an expandable cordless but it really made no sense to me. How am I going to find out if the prospective providers gear sends aut the signal? That is a mystery. Murray

Murray:

You shouldn't have to ask them, and I think that most VOIP dial tone providers have figured this out now. It's not just 1A2 hardware that requires the disconnect signal, it's all systems. No need to worry about the 1A2 damaging the VOIP hardware: It's harmless since it sends absolutely nothing toward the line itself. If you have a lot of phones ringing directly from the CO line, you might have an issue with ringer load, but VOIP eqipment should be designed to support the national standard of 5.0 REN, or basically five ringers connected directly to the line. You probably don't need to worry about that since it's usually the case that power to the ringers is locally-generated. Don't sweat it.

Thanks Ed! I wonder why they even discourage connecting to a group of wired phones. The ringing is generated in the KSU. I switched from copper to fiber with Verizon Fios and now the inline gadgets on the single line phones activate the lights on the system but do not take it off hold. Is there an easy way to deal with that?

Murray

Ed, knee-jerk reaction. VOIP equipment only putting out 24-27 volts on hook? And not enough current flow off-hook to trigger A-lead accessory controller? These used to be low-current relays, but I think the last few years they built them they used electronic sensors that were less demanding about current required to trigger the closure. Maybe Murray needs some real recent a-lead controllers, and I know who has the best chance of having them. John C.

Hello clightinghorse, Two seperate but probably related issues. I have not moved to voip as yet. The problem with the A-lead controllers came up when I switched to fiber from copper. Where could I procure a new controller to try? Thanks! Murray

True, SLT devices connected behind the 551 will require A-lead adapters and less than 48 volts might present a problem. Line voltage will not have any impact upon the system's regular phone operation.

Dial tone is dial tone. 1A2 equipment is very tolerant of variable line voltages. As long as disconnect supervision is sent by the carrier, all will be fine. That is your key.

Murray: If you switch a line to VOIP, here's a simple test: Grab the line and place it on hold. If it doesn't drop off and go to idle after about 20 seconds, then your VOIP dial tone provider isn't sending the disconnect signal. It should be easy to test using this method.

I have the A-lead controllers for sale, but I really don't think that you need them.

Thanks Ed, The A-lead control of taking the phone off hold with the SLT went away when I switched to Fios. I tried moving around two or three different controllers that I have used in the system for about 20 years. The voltage out of the fiber unit is undoubtedly lower then Ma Bell had been feeding me. Do the A-lead devices that you have work on a lower voltage? Thanks! Murray

Murray:

Yes, the A-lead adapters that I have work on voltages as low as 24 volts.