[AVT] RE: Comments on draft-ietf-avt-mime-h224-02.txt
"Even, Roni" <roni.even@polycom.co.il> Mon, 27 June 2005 13:52 UTC
Received: from localhost.localdomain ([127.0.0.1] helo=megatron.ietf.org) by megatron.ietf.org with esmtp (Exim 4.32) id 1Dmu2Z-0007MO-Fy; Mon, 27 Jun 2005 09:52:47 -0400
Received: from odin.ietf.org ([132.151.1.176] helo=ietf.org) by megatron.ietf.org with esmtp (Exim 4.32) id 1Dmu2X-0007ME-LD for avt@megatron.ietf.org; Mon, 27 Jun 2005 09:52:45 -0400
Received: from ietf-mx.ietf.org (ietf-mx [132.151.6.1]) by ietf.org (8.9.1a/8.9.1a) with ESMTP id JAA22137 for <avt@ietf.org>; Mon, 27 Jun 2005 09:52:42 -0400 (EDT)
Received: from fw.polycom.co.il ([212.179.41.2] helo=isrexch01.israel.polycom.com) by ietf-mx.ietf.org with esmtp (Exim 4.33) id 1DmuRg-000338-Lw for avt@ietf.org; Mon, 27 Jun 2005 10:18:45 -0400
x-mimeole: Produced By Microsoft Exchange V6.5.7226.0
Content-class: urn:content-classes:message
MIME-Version: 1.0
Content-Type: text/plain; charset="us-ascii"
Content-Transfer-Encoding: quoted-printable
Date: Mon, 27 Jun 2005 16:53:41 +0300
Message-ID: <144ED8561CE90C41A3E5908EDECE315C01E9D04A@IsrExch01.israel.polycom.com>
Thread-Topic: Comments on draft-ietf-avt-mime-h224-02.txt
Thread-Index: AcV7Ffex86RASWmBQWKaxiUAwFo+uwAAvG/g
From: "Even, Roni" <roni.even@polycom.co.il>
To: Magnus Westerlund <magnus.westerlund@ericsson.com>, IETF AVT WG <avt@ietf.org>
X-Spam-Score: 0.0 (/)
X-Scan-Signature: dbb8771284c7a36189745aa720dc20ab
Content-Transfer-Encoding: quoted-printable
Cc:
Subject: [AVT] RE: Comments on draft-ietf-avt-mime-h224-02.txt
X-BeenThere: avt@ietf.org
X-Mailman-Version: 2.1.5
Precedence: list
List-Id: Audio/Video Transport Working Group <avt.ietf.org>
List-Unsubscribe: <https://www1.ietf.org/mailman/listinfo/avt>, <mailto:avt-request@ietf.org?subject=unsubscribe>
List-Post: <mailto:avt@ietf.org>
List-Help: <mailto:avt-request@ietf.org?subject=help>
List-Subscribe: <https://www1.ietf.org/mailman/listinfo/avt>, <mailto:avt-request@ietf.org?subject=subscribe>
Sender: avt-bounces@ietf.org
Errors-To: avt-bounces@ietf.org
Magnus, Thanks for going over the document. In line Roni -----Original Message----- From: Magnus Westerlund [mailto:magnus.westerlund@ericsson.com] Sent: Monday, June 27, 2005 3:43 PM To: Even, Roni; IETF AVT WG Subject: Comments on draft-ietf-avt-mime-h224-02.txt Hi Roni, I have some comments on the draft: 1. First, it is quite irritating that the draft lacks the correct page break markers. Roni: I am using xmk2rfc so it is a bit strange, can you show me an example. 2. Section 1, Introduction I think the introduction could be clarified to better explain: - The media type is for H.224 over RTP, with packetization according to Annex Q of H.323. - FECC is the only real usage of H.224, however the protocol is not limited to FECC. Roni: I tried to make it short based on Colin's comment. But I can make it more in line with you comment. Another comment is that media type registrations are done to not be limited to SDP. However other protocols like SDP-NG or FOO would need to specify a mapping. Therefore I have some problems with the usage of SDP-based. However I do not have a better proposal. Roni: I assume that this is a general comment applicable to all medi type registration. So if there is are guidelinesI would follow them. Due to this I would prefer to have some attempt to improve the introduction for clarity. 3. On a number of places there is missing spaces between the text and the brackets ([ or ]) for the references. Roni: OK, so the right way is with space. 4. Section 4. I think you should clarify that this registration is also in accordance with RFC 3555. Roni: I will do it, does this apply to all media type registerations? 5. I am missing the "Restrictions on usage:" entry. I would suggest that you use the following text: This media type depends on RTP framing, and hence is only defined for transfer via RTP [3]. Transport within other framing protocols is not defined at this time. Roni: OK 6. The encoding consideration should be clarified to indicate what type of data this is. Again I think the following text would be appropriate to add. This media type is framed (see section 4.8 in [31]) and partially contains binary data. Roni: OK 7. Section 5. First bullet: "The media name in the "m=" line of SDP MUST be application. The transport SHOULD be RTP and the payload type is dynamic." I have two questions here. First is why it is only a SHOULD in regards to RTP. To me this media type is defined for RTP only and can with defined transport only be used with RTP. Usage of another transport than RTP would require explicit signalling. Secondly wouldn't it be better to discuss also profiles? There should be no limitations when it comes to profiles, but as it is the combination of RTP and profile etc it might be appropriate to mention this. Roni: I will change to SHALL. As for the profile I can only refer to current profiles, I will add a sentence like "any applicable RTP profile (e.g., [RFC3551])" 8. Section 5, third bullet: The clock rate in the "a=rtpmap" line MUST be 0. Here I see a serious problem. RTP needs an clock rate, 0 is not a valid value here. Is there a clock rate defined when using annex Q or is it media dependent. Roni: Thanks, the default in annex Q is 4800, I will fix it. 9. Section 6, first paragraph. RTP packets using the payload format defined in this specification are subject to the security considerations discussed in the RTP specification [RFC3550]. I prefer the extended sentence that discusses profiles also: RTP packets using the payload format defined in this specification are subject to the security considerations discussed in the RTP specification [RFC3550] and any applicable profile, e.g. RFC 3551 or RFC 3711. Roni: OK 10. Section 6. I am missing a discussion on the security sensitivity of the H.224 content of the RTP packets. As H.224 contains a negotiation protocol it seems it would be very sensitive to attacks. Also rouge control of the camera may need to be discussed. I think this should be used as motivation for using authentication and integrity protection. Roni: OK 11. Section 7. I think it might be best if all the MIME registration related references are informal: RFC 3555, RFC 2048 and Freed's draft. OK Cheers Magnus Westerlund Multimedia Technologies, Ericsson Research EAB/TVA/A ---------------------------------------------------------------------- Ericsson AB | Phone +46 8 4048287 Torshamsgatan 23 | Fax +46 8 7575550 S-164 80 Stockholm, Sweden | mailto: magnus.westerlund@ericsson.com _______________________________________________ Audio/Video Transport Working Group avt@ietf.org https://www1.ietf.org/mailman/listinfo/avt
- [AVT] Comments on draft-ietf-avt-mime-h224-02.txt Magnus Westerlund
- [AVT] RE: Comments on draft-ietf-avt-mime-h224-02… Even, Roni
- [AVT] Re: Comments on draft-ietf-avt-mime-h224-02… Magnus Westerlund
- Re: [AVT] RE: Comments on draft-ietf-avt-mime-h22… Tom Taylor
- RE: [AVT] RE: Comments on draft-ietf-avt-mime-h22… Even, Roni
- RE: [AVT] RE: Comments on draft-ietf-avt-mime-h22… Even, Roni
- [AVT] Comments on draft-ietf-avt-mime-h224-02.txt kae
- RE: [AVT] Comments on draft-ietf-avt-mime-h224-02… Even, Roni
- RE: [AVT] Comments on draft-ietf-avt-mime-h224-02… Gunnar Hellstrom
- RE: [AVT] Comments on draft-ietf-avt-mime-h224-02… kae
- RE: [AVT] Comments on draft-ietf-avt-mime-h224-02… kae
- RE: [AVT] Comments on draft-ietf-avt-mime-h224-02… Even, Roni
- RE: [AVT] Comments on draft-ietf-avt-mime-h224-02… Even, Roni
- RE: [AVT] Comments on draft-ietf-avt-mime-h224-02… kae
- RE: [AVT] Comments on draft-ietf-avt-mime-h224-02… kae
- RE: [AVT] Comments on draft-ietf-avt-mime-h224-02… Gunnar Hellstrom