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The call I am tracing is supposed to use the 180 Ringing SIP message to indicate to the caller that the callee has recevied the invite, and the caller can play ring back tone to the caller's speaker. This call should not be sending the ring back tone encoded as audio into RTP. When using the RTP player utility to decode the call audio, the player plays out a ring back tone as part of the audio decocde.

My question is, is the RTP player seeing the 180 Ringing in the packet trace and using that to trigger ring back tone in the audio playout? Or is the RTP player just playing out what is decoded from the RTP, meaning the ring back tone was encoded as audio into RTP packets?

Thanks, Carl

asked 12 Sep '13, 09:12

cklatsky's gravatar image

accept rate: 0%

The audio player will not add any audio by it self. The ring back tone is normaly used as a trough connection test and is sent by the B subscriber or equipment as close to the B subscriber as possible.

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answered 12 Sep '13, 21:54

Anders's gravatar image

Anders ♦
accept rate: 17%

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question asked: 12 Sep '13, 09:12

question was seen: 2,468 times

last updated: 12 Sep '13, 21:54

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