John,

You wrote:

> RFC 3264 does indeed tell you to do that. In section 5.1 it states:
> "If the offerer wishes to communicate, but wishes to neither send nor 
> receive media at this time, it MUST mark the stream with an "a=inactive" 
> attribute." 

> The problem is, this appears to be contradicted elsewhere. 

The problem is in RFC 3264 section 8.4. It states:
"If the stream to be placed on hold was previously a sendrecv media
stream, it is placed on hold by marking it as sendonly." This sentence
is more often false then true and should not be considered normative.

I think the original intent of this text was to say that that SDP with 
c=0.0.0.0 corresponds to sendonly SDP and not inactive SDP. Since
SDP with c=0.0.0.0 used to be called hold SDP, sending an offer with such 
SDP was normally called putting on hold. Hence the confusion.

In generall, it would be a good idea to remove mentioning of term hold from
RFC 3264. Also, correspondence between SDP with c=0.0.0.0 and sendonly SDP
should be spelled out. This should not change anything in the meaning
of the RFC, but hopefully will end the hold confusion.
___________________________________
Roman Shpount, VP of Technology
aTelo, Inc. -- www.atelo.com







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