Subject: [AVT] Profile specification

From: "Mainka Fedrick" <[email-masked]>
Date: Fri, 12 Dec 2003 18:29:34 +0000

Hi all,

In RFC3550 section 5.3.1, it is stated that "The format of these 16 bits is 
to be defined by the profile specification under which the implementations 
are operating."

May I know what is the meaning of profile in this case? Is this "profile 
specification" the same profile under which the PT type can be defined (see 
section 5.1 under payload type)? Does a profile specify the format of the 
Marker Bit, the Payload Type and use of Header Extension?

Best Regards,
Fedrick

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From: Stephen Casner <[email-masked]>
Date: Fri, 12 Dec 2003 11:37:25 -0800 (PST)

On Fri, 12 Dec 2003, Mainka Fedrick wrote:

> section 5.1 under payload type)?

The term "profile" is defined in Section 1, and I believe that term is
used consistently throughout the document.  That is, there should be
no other meanings.  Therefore, the short answer to your question is
yes.

> Does a profile specify the format of the Marker Bit, the Payload
> Type and use of Header Extension?

Yes.  Section 13 lists aspects that may be defined in a profile.  So
far, all of the profiles that have been written simply follow the
default format in the main RTP spec for the format of the Marker and
PT byte, and none have defined Header Extensions.  Only one profile
has been published as an RFC (that's 3551 which updates 1890), but two
more are about to be published.

                                                        -- Steve