AAC SDP Payload for receive only stream

Question

I want to create a sdp for receiving a AAC stream.. I will not be sending out any stream Consider the following payload:

m=audio 50002 RTP/AVP 97

a=rtpmap:97 mpeg4-generic/16000/1

a=fmtp:97 streamtype=5; profile-level-id=15; mode=AAC-hbr; config=1408; sizeLength=13; indexLength=3; indexDeltaLength=3; profile=1; bitrate=64000;

The fmtp parameters would only depend on the sender because this is a receive only stream. I do not know the values of the config/bitrate and other parameters of the sender. So what should be the correct values of this parameters for the request?

Answer 1

Remember that SIP's offer/answer model allows for either the caller or the callee to send the offer.

If you cannot describe the desired media before you've seen the sender's media streams, why not have the sender supply the offer, and base your answer on that?