[xrblock] FW: SDP directorate review of draft-ietf-xrblock-rtcp-xr-video-lc-01

["Huangyihong (Rachel)" <[e-mail]>]

BR,
Rachel


-----Original Message-----
From: Christer Holmberg [mailto:[e-mail]] 
Sent: Friday, August 14, 2015 5:36 PM
To: mmusic; Shida Schubert ([e-mail]); Romascanu, Dan (Dan); [e-mail]; [e-mail]; [e-mail]
Subject: SDP directorate review of draft-ietf-xrblock-rtcp-xr-video-lc-01

(Sending again, with the correct e-mail addresses)

Hi,

I have done an SDP directorate review of draft-ietf-xrblock-rtcp-xr-video-lc-01. 

In general I didn't find any major issues, but I do have a few editorial comments that the authors may wish to address.


Q1:

The text in section 5 says:

	"However XR blocks MAY be used without prior signaling (see section 5 of [RFC3611])."

I suggest to remove the sentence, as the previous sentence refers to RFC 3611 for the generic SDP considerations.

IF you want to keep the sentence, I think MAY should not be in capital letters, as you are referring to a rule defined elsewhere. 


Q2:

In section 5.1, the value for the extension is defined as "video-loss-concealment".

Couldn't it be shorter, e.g. simply "vlc"? The size of a typical SDP message body is already very big, so...

Also, if you look as the XR blocks defined in RFC3611, they mostly use abbreviations too.


Q3:

The text in section 5.2 says:

	"When SDP is used in offer-answer context, the SDP Offer/Answer usage
   	defined in [RFC3611] for unilateral "rtcp-xr" attribute parameters
   	applies.  For detailed usage of Offer/Answer for unilateral
   	parameter, refer to section 5.2 of [RFC3611]."

I suggest to remove the second sentence. If you want to mention section 5.2 of RFC3611, you can do that in the first sentence, e.g.:

	"When SDP is used in offer-answer context, the SDP Offer/Answer usage
   	defined in section 5.2 of [RFC3611] for unilateral "rtcp-xr" attribute parameters
   	applies."

Regards,

Christer