Customer has comcast phone service from Arris unit. We measured 47-48vdc and 38mA current coming from the modem. Current is high but never have had an issue yet. Customer complains of no speech, phone rings, nothing there. Then they call the customer back and can talk. Happens on an intermittent basis. Comcast replaced modem and some outside filters.

Considering Sandman loop current regulators at this point but not sure if that is going to solve the problem.

Does the customer utilize an auto attendant? If so, check to see that Comcast is providing a positive disconnect. Specifically, Comcast needs to momentarily kill the voltage on the line to indicate to the auto attendant that the calling party has hung up. Without the disconnect indication, the auto attendant will keep the telephone line seized, and the Timeout action setting would dictate what happens from there.

no auto-attendant. phone rings, caller id is a known customer, but no speech. lousy situation.

So it's not a case of positive disconnect then.

This sounds similar to a situation where users of ISDN/PRI services hear their phones ring, but, nobody is there.

Trapping messages on the "D" channel reveals a glitch that prevents the audio from turning on, thus the called party hears dead air.

Given that this problem is intermittent, Comcast could have a problem upstream. Calls hit a bad circuit and it fails. Another call hits a different circuit and all is well.

My suggestion....have Comcast verify the modem's programming. If it is confirmed to be good, have them trace out bad calls to see if they all have something in common.

thanks for the good advice!

Comcast tech called and admitted they have a known issue of 'ghosting' and are working to resolve it. He called it 'ghosting'. Phone rings, customer answers and no speech. They have a fix to be implemented. We shall see..

Let us know what the final outcome is.

Guys, just to chime in--I deal with this issue a lot.

Nowadays, most cable providers are using these Arris TG series gateways to provide POTS to customers. All the Arris does is send the voice as data to the CMTS, and from there it is transported as SIP/VoIP.

More than once I've run into this issue and it has been a problem with the provider's VoIP infrastructure. It takes some major convincing to get them to look at it, but we can usually get it resolved.

EDIT: With SIP, the two endpoints talk to each other and negotiate a random port to transport audio on. If there is too much latency between the two endpoints, it can result in this behavior, or even one way audio.

I have 3 customers on Spectrum this week that are having those same issue's ghost calls and ring backs with dead air. Spectrum states it's been a nationwide issue since Friday Nov 30th Still not fixed as of this morning....

The problem has subsided here for the most part. Late August through September we got alot of calls from various customers. The 'Comcast fix' seems to be working. We were told by a field technician the issue was specific to Comcast and calls from Verizon wireless which is the biggest cell phone carrier.