Hello, RFC 5009 mainly talks about early media authorization by UAS toward UAC only. It is not clear how to handle the ealry media authorization request coming from UAC. Currently we encountered an issue on our B2BUA implementation.
As per the implementation requirement by the client, B2BUA has to repeat the previous P-Early-Media value received from UAS towards UAC in all supported messages (eg 18x, Update & PRACK ) messages. For an example if UAS has sent P-Early-Media :senonly on 1st 18x, and if subsequent 18x from UAS doesn't contain P-Early-Media header, then B2BUA has to remember the P-Early-Media received on 18x and to provide it to UAC. This fine and works well. The issue started occurring network when B2BUA started sending P-Early-Media in PRACk request towards UAS. For an example, UAC B2BUA UAS | 1:INVITE(SDP) | | +----------------------->| | | 2:100[INV] | | |<-----------------------+ | | | 3:INVITE(SDP) | | +----------------------->| | | 4:100[INV] | | |<-----------------------+ | | 5:180[INVITE](SDP) | | |<-----------------------+ | 6:180[INVITE](SDP) |P-Early-Media=sendonly | |<-----------------------| | |P-Early-Media=sendonly | | | | 7:183[INVITE] | | |<-----------------------+ | 8:180[INVITE](SDP) | | |<-----------------------| | | P-Early-Media=sendonly | | | | | | 9:PRACK | | +----------------------->| 10:PRACK | | |----------------------->| | | P-Early-Media=sendonly | Here you can see the message 10 B2BUA repeated the P-Early-Media value of that dialog towards UAS and caused issues at UAS. The question is 1) How the P-Early-Media value sent by UAC is interpreted? 2) Can you please explain a P-Early-Media value of sendrecv, sendonly , recvonly & inactive by UAC has to be interpreted by UAS. 3) Can we treat P-Early-Media sent by UAS and UAC independently or is those are relative? 4) If UAS sent P-Early-Media sendonly on 18x for enabling backward media and if B2BUA has to include P-Early-Media (due to some business logic) in PRACK request, what has to be the value (sendonly or recvonly)?. The value must not affect backward media flow. -- Thanks & Regards Dinoop p _______________________________________________ Sip-implementors mailing list Sip-implementors@lists.cs.columbia.edu https://lists.cs.columbia.edu/mailman/listinfo/sip-implementors
