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Trace 183 Ringing

asked 2017-12-18 01:41:48 +0000

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How to troubleshoot no ring back on outgoing sip calls

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answered 2017-12-18 09:33:49 +0000

Jaap gravatar image

Have a look at media negotiation (through SDP) in this phase of the call. Early media can be there, to provide far end ring back tone. Or if it's not there, it should be generated locally by your terminal.

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But the calling UA (terminal) should generate the alert confirmation tone to the calling user only if the called either sends a 180 with no SDP in it or if the SDP negotiation could not be completed because the INVITE contained no SDP and so the one in 180 is an offer and 100rel is not supported in that dialog.

If conditions for early media are met (SDPs exchanged, no SDP-less 180 seen), the remote party is responsible for providing the tone.

sindy gravatar imagesindy ( 2017-12-18 11:04:13 +0000 )edit

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Asked: 2017-12-18 01:41:48 +0000

Seen: 909 times

Last updated: Dec 18 '17