I'm sure i'm not the first to experience this. My polycom phones when calling out a pstn gateway recieve far end ringing when dialing cellphones in the US, but when i try to call a pots line i get no ringing, only silence until the end point answers the call.
Does anyone have a solution for this? From what i can see in the sip captures, the gateway sends a 180 ringing on the pots line calls, but when i call a cellphone i recieve a 183 Session Progress where the phones do provide the ringing. A polycom to polycom call shows the same 180 ringing, but in this case they do provide ringing.
Just to be clear, the ringing i am talking about is the rinigng you here in the earpiece after a dial.
Any insight or help would be very appreciated. I have sip captures that i can post, but opted not to incase someone has seen this and knows the answer first.
Thanks so much!
On Friday 25 July 2008, Alex G wrote:
I'm sure i'm not the first to experience this. My polycom phones when calling out a pstn gateway recieve far end ringing when dialing cellphones in the US, but when i try to call a pots line i get no ringing, only silence until the end point answers the call.
Any insight or help would be very appreciated. I have sip captures that i can post, but opted not to incase someone has seen this and knows the answer first.
Hi Alex,
perhaps the PSTN gateway or your polycom don't support early media? Check if RTP is flowing in the "silent" case before the call is finally established (with 200 OK).
Cheers,
Henning
Henning Westerholt wrote:
On Friday 25 July 2008, Alex G wrote:
I'm sure i'm not the first to experience this. My polycom phones when calling out a pstn gateway recieve far end ringing when dialing cellphones in the US, but when i try to call a pots line i get no ringing, only silence until the end point answers the call.
Any insight or help would be very appreciated. I have sip captures that i can post, but opted not to incase someone has seen this and knows the answer first.
Hi Alex,
perhaps the PSTN gateway or your polycom don't support early media? Check if RTP is flowing in the "silent" case before the call is finally established (with 200 OK).
Another possibility is that -- depending on what is on the far side of the PSTN gateway (PRI?) -- the ringing is not sent in-band, and the appropriate translation of the ISDN progress indicator ("PI") to OOB ringing events is not configured?
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Alex Balashov -
Alex G -
Henning Westerholt