trouble with coupler over VOIP

[ellenparks]

Anybody had this happen? I am having trouble getting two different ( manufacturers) telco answerer-couplers to work on VOIP from the cable company. At first I discovered that the answerer-couplers would answer fine but then the audio coming from the cable modem would osscillate with a low hissing sound garbeling the call. If you were quiet for 30 seconds the oscillation faded away and you could talk just fine. But, if you happpened to hit a number key on the phone keypad on either end or talked too loud the oscillation started again. This happened with both couplers and even when I siezed the line using a repeat coil and headphone.

The second thing that happened was when the answerer-coupler failed to disconnect when I hung up from the opposite end. The VOIP then went into a buizy signal which held the coupler for hours. This has never happened with either coupler on a POTS line in he past.

Cable says their modem is fine. This happened when therewas absolutely no other equipment on the line just a run from the cable modem to the coupler. Any ideas what's going on?

 

[stephend2]

I've seen some weird stuff on VoIP with an impedance mismatch, some of the ATAs that I've used have adjustments for this, of course the cable co. isn't going to give any access to this on their modem. As far as the hangup, most VoIP services do not signal hangup properly. We have this trouble interfacing with PBXs all the time. Again, higher end ATAs can be tweaked to do this properly and you won't have access to the modem you have. Is this an Arris modem by chance ?

 

[ellenparks]

Makes sense thanks. Ok, my voip goes to buisy aftr 10 seconds unconnected on the sending end . Can anybody reccomend a answer-coupler that detects a buisy signal and hangs up?

 

[Kmagrill]

Makes sense thanks. Ok, my voip goes to buisy aftr 10 seconds unconnected on the sending end . Can anybody reccomend a answer-coupler that detects a buisy signal and hangs up?

Sure, that's easy. You probably won't have to buy new couplers.

The industry standard requires that the telephone line switch off the DC battery voltage on the phone line whenever a call ends. Most true phone lines that are provided by a central office have this feature. The DC battery voltage control is called CPC (Calling Party Control) or one of several other names. It is this feature that allows telephone coupler devices to automatically disconnect when the call is ended. If the phone line (or analog port) does not have this required CPC feature, then the autocoupler, will not be able to automatically disconnect from the line when the call is over.

Call progress decoders listen for common tones on the phone line and then force attached coupler devices to disconnect when one of the known tones is present on the line.

We (CircuitWerkes) makes call progress decoders in two flavors. The CP-1 is a daughter board that works with our couplers. When the CP-1 detects dial-tone, busy or any of several other possible signals, it sends a logic command to the host board forcing a disconnect.

If your coupler's not one of ours, we make a product called the CP-2 which is a little stand alone box that can be inserted between the telephone port and any brand of autocoupler. When the CP-2 detects dial-tone or busy it momentarily opens the line forcing a disconnect. More info is online at:

http://www.broadcastboxes.com/products/CP-2_lit.html

Instructions for the products are at:

http://www.broadcastboxes.com/pdf/CircuitWerkes_CP-1M_Instructions.pdf
and
http://www.broadcastboxes.com/pdf/CP-2_01-00.pdf

I always suggest that you check out your VOIP adapter to make sure it cannot be set to provide CPC before investing in a call progress decoder. The best solution is to get the adapter to do the job properly. Only if that is impossible should you use a call progress decoder.