Subject: Re: [RAI] media-policy-dataset: "q" attribute

From: "Worley, Dale R (Dale)" <[email-masked]>
Date: Thu, 1 Sep 2011 15:08:38 -0400

To have the "q" attribute on <codec> specify the ordering of
codecs in m= lines, I've added the following text.  I think it captures
what we expect to happen.

Index: draft-ietf-sipping-media-policy-dataset-13.xml
===================================================================
--- draft-ietf-sipping-media-policy-dataset-13.xml	(revision 4671)
+++ draft-ietf-sipping-media-policy-dataset-13.xml	(working copy)
@@ -408,7 +408,11 @@
       The UA MUST insert the media type
       from the m= line into a &lt;media-type&gt; element and MUST
       create a &lt;codec&gt; element for each codec listed in the m=
-      line.</t>
+      line.
+      The &lt;codec&gt; elements must have q attributes with values
+      that decrease with the order the codecs are given in the m=
+      line.  (Other than the ordering restriction, the particular
+      values used are not specified by this document.)</t>
 
       <t>The UA MUST create a &lt;local-host-port&gt; element for each
       stream using the port taken from the m= line and the address
@@ -443,8 +447,12 @@
       of the appropriate &lt;stream&gt; element.</t>
 
       <t>The mapping from a session info document to a SDP description
-      follows the same rules in the reverse direction.</t>
+      follows essentially the same rules in the reverse direction.</t>
 
+      <t>For any particular m= line, the codecs must be listed in
+      decreasing order of the values of the q attributes of the
+      corresponding &lt;codec&gt; elements.</t>
+
     </section>
 
     <section title="The &lt;session-info&gt; Element">

Dale