Subject: [MMUSIC] SDP comments on draft-singh-avtcore-mprtp-02: Packet Formats (Section 9)

From: Christer Holmberg <[email-masked]>
Date: Wed, 3 Aug 2011 23:06:17 +0200

Hi,

Below are my comments/questions on section 9.

Regards,

Christer

Section 9.1:

	ED_9_1-1: I don't understand the text about the urn. What is it, and where is it used? In addition, 
	if it is SDP specific, I think it belongs to section 11.

Section 9.1.3

	FU_9_1_3-1: Even if you do NOT do RTP/RTCP multiplexing, do you really need a dedicated keep-alive 
	MPID ID? Can't you simply use RTP for keep-alive as defined in RFC 6263?

Section 9.3.

	The text says:

	"This sub-section defines the RTCP header extension for in-band
      interface advertisement by the receiver, instead of relying on ICE or
      in situations when the interface appears after SDP session
      establishment."

	ED_9_3-1: Should the text say "instead of relying on SDP or ICE"? Because, you don't need ICE in order 
	to use the new SDP interface attributes used in the document.

	ED_9_3-2: The text seems to suggest that you can't do mid-session modifications (including 
	addition of interfaces) using SDP, which is not true.

Section 9.3.1:

	FU_9_3_1: If I advertise an interface, what does it mean? Does it mean, similar to SDP, that I 
	am willing to receive media on this interface? OR, does it mean that I am willing to send AND receive media 
	on this interface?