I have a strange situation where after anything from 10-25 minutes, I can no longer hear anything from the other party on my call, but they can hear me just fine. It never recovers, I need to hang up. I usually have to say “I lost you, call me back”. Weird huh. They can usually call me right back just 2 seconds later no problem and then we have again 10-25 minutes before it re-occurs. On a one hour conference call I usually end up having 3 such dropouts.
Asterisk server running in New York at my employers. There’s only 1 IP phone connected to it, mine. My phone is at home here in Germany. It’s connected to my router which keeps my DSL connection alive 24/7. It only is forced to renew the DSL lease once per day and that never happens during the call because I force the renew as soon as I wake up so that it’s done on my terms and not when I’m not expecting it.
Our IT department in NYC aren’t VOIP experts but they’re very good. They say they see no problems with the line during one of these one-way dropouts. Network traffic is light usually, ping responsiveness is reasonable (under 200ms) and all looks good. They HEAR me perfectly during a half-dropout.
On my side I’ve port-forwarded all the ports the IT department told me to on my router to the phone (5060 and 10000-10015 UDP). I’ve disabled the DoS attack defense functionality of the router, I’ve even tried setting the phone’s IP as a DMZ host.
It seems like it would probably be something at my end but I’m out of ideas. There’s so many options in my phone that to list them all would probably be pointless as I imagine only a handful would be relevant. I’m using SIP (not IAX) and the phone is a noname chinese model, but I had the same problem with a Grandstream BT100. The config pages for the phones are totally different but somehow the problem persists across both. That leads me to think it’s something outside the phone.
If I can’t get an answer here I’m tempted to try (the surprisingly difficult with my router config) configuring the phone to get the PPPoE DSL connection itself (which it’s capable of) thus bypassing my router. If that doesn’t work then it must be either my ISP or really something at my employer’s end.
Anyone have ideas?