[AVTCORE] Update to RFC5285 allowing both one and two bytes header extensions in the same RTP packet

"Roni Even" <ron.even.tlv@gmail.com> Fri, 11 September 2015 08:13 UTC

Return-Path: <ron.even.tlv@gmail.com>
X-Original-To: avt@ietfa.amsl.com
Delivered-To: avt@ietfa.amsl.com
Received: from localhost (ietfa.amsl.com [127.0.0.1]) by ietfa.amsl.com (Postfix) with ESMTP id 5DDF11B3001 for <avt@ietfa.amsl.com>; Fri, 11 Sep 2015 01:13:14 -0700 (PDT)
X-Virus-Scanned: amavisd-new at amsl.com
X-Spam-Flag: NO
X-Spam-Score: -0.1
X-Spam-Level:
X-Spam-Status: No, score=-0.1 tagged_above=-999 required=5 tests=[BAYES_20=-0.001, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, FREEMAIL_FROM=0.001, HTML_MESSAGE=0.001, SPF_PASS=-0.001] autolearn=ham
Received: from mail.ietf.org ([4.31.198.44]) by localhost (ietfa.amsl.com [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id 9d_DJyKc2sIg for <avt@ietfa.amsl.com>; Fri, 11 Sep 2015 01:13:12 -0700 (PDT)
Received: from mail-wi0-x229.google.com (mail-wi0-x229.google.com [IPv6:2a00:1450:400c:c05::229]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by ietfa.amsl.com (Postfix) with ESMTPS id F13811A9005 for <avt@ietf.org>; Fri, 11 Sep 2015 01:13:11 -0700 (PDT)
Received: by wiclk2 with SMTP id lk2so54952095wic.0 for <avt@ietf.org>; Fri, 11 Sep 2015 01:13:10 -0700 (PDT)
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=from:to:subject:date:message-id:mime-version:content-type :thread-index:content-language; bh=rFvsDYv+9hRdwsVx4UijUi8nhqeyI+nwuHYoABYDdFI=; b=DJmsVOnrugpZBWnMtqO4XWRgEjTVC7xAHrKhOLwQHHnfwgaX5PfX7nSmAWPXIIKfWb BCO+a2qb92XFHA2ecTmkvdnAjOl4ewtl1fHYPOcBdXYgU0SZZcJH7WNxPQG2nJ5gUYSL xKYxIFYdO5/EJjJjhWZrGVb2bqNpq1pq8ep3NDuzxeZF9xw7lW/FjAQ4Vmtt4LYudSp8 zmn6ZGsq1892qFsHaVXp4k5Lr6xWRXMM6XWA0jhteZ78ieEcaJdyzyq6t0BFEzDGRisQ WdTTy7QehS7k5Yp4t4r61QGEC1tuFSzHJ2rxhvlD1NPXAEOqXwt0wMwtKUH+Qf7/GVRG +thQ==
X-Received: by 10.194.171.129 with SMTP id au1mr83093759wjc.115.1441959190512; Fri, 11 Sep 2015 01:13:10 -0700 (PDT)
Received: from RoniPC (bzq-79-180-110-132.red.bezeqint.net. [79.180.110.132]) by smtp.gmail.com with ESMTPSA id d8sm2292111wiy.1.2015.09.11.01.13.08 for <avt@ietf.org> (version=TLSv1 cipher=ECDHE-RSA-AES128-SHA bits=128/128); Fri, 11 Sep 2015 01:13:09 -0700 (PDT)
From: "Roni Even" <ron.even.tlv@gmail.com>
To: <avt@ietf.org>
Date: Fri, 11 Sep 2015 11:13:02 +0300
Message-ID: <04a801d0ec69$aec10170$0c430450$@gmail.com>
MIME-Version: 1.0
Content-Type: multipart/alternative; boundary="----=_NextPart_000_04A9_01D0EC82.D410F890"
X-Mailer: Microsoft Outlook 14.0
Thread-Index: AdDsaBApNFPehXcdSKubD36IR+oRPA==
Content-Language: he
Archived-At: <http://mailarchive.ietf.org/arch/msg/avt/uyCIfwyf5c78lHA2GKv9zvTFai4>
Subject: [AVTCORE] Update to RFC5285 allowing both one and two bytes header extensions in the same RTP packet
X-BeenThere: avt@ietf.org
X-Mailman-Version: 2.1.15
Precedence: list
List-Id: Audio/Video Transport Core Maintenance <avt.ietf.org>
List-Unsubscribe: <https://www.ietf.org/mailman/options/avt>, <mailto:avt-request@ietf.org?subject=unsubscribe>
List-Archive: <https://mailarchive.ietf.org/arch/browse/avt/>
List-Post: <mailto:avt@ietf.org>
List-Help: <mailto:avt-request@ietf.org?subject=help>
List-Subscribe: <https://www.ietf.org/mailman/listinfo/avt>, <mailto:avt-request@ietf.org?subject=subscribe>
X-List-Received-Date: Fri, 11 Sep 2015 08:13:14 -0000

Hi,

At IETF94 there was a consensus to allow mixing of one byte and two bytes
header extensions in the same RTP packet.  I volunteered to do the update to
RFC5285.

 

The issue I have s how to pack both one and two bytes in the same RTP
packet.

 

Currently the extension header (as specified by the profile) is 0xBEDE for
one byte only headed extension and 0x100 followed by 4 bits called appbits
for the two bytes header extension 

 

 

"The appbits field is 4 bits that are application-dependent and may be

   defined to be any value or meaning, and are outside the scope of this

   specification.  For the purposes of signaling, this field is treated

   as a special extension value assigned to the local identifier 256.

   If no extension has been specified through configuration or signaling

   for this local identifier value 256, the appbits field SHOULD be set

   to all 0s by the sender and MUST be ignored by the receiver."

 

 

My proposal is to keep this two options and add a new extension header 0x200
followed by the 4 bits appbits (using the same semantics) and mandate having
first one byte header extensions terminated by a one byte header extension
with ID 15 which in this case will not terminate the header extensions but
signal the start of the two bytes header extension part.

 

Does this looks reasonable

 

Thanks

Roni Even

As individual