Re: [AVTCORE] Multi-party real-time text requiring new RTP payload type Thu, 23 April 2020 02:27 UTC

Return-Path: <>
Received: from localhost (localhost []) by (Postfix) with ESMTP id 6F0143A1134 for <>; Wed, 22 Apr 2020 19:27:16 -0700 (PDT)
X-Virus-Scanned: amavisd-new at
X-Spam-Flag: NO
X-Spam-Score: -0.983
X-Spam-Status: No, score=-0.983 tagged_above=-999 required=5 tests=[BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, HEADER_FROM_DIFFERENT_DOMAINS=0.25, SPF_HELO_NONE=0.001, SPF_SOFTFAIL=0.665, URIBL_BLOCKED=0.001] autolearn=no autolearn_force=no
Authentication-Results: (amavisd-new); dkim=pass (2048-bit key)
Received: from ([]) by localhost ( []) (amavisd-new, port 10024) with ESMTP id Vhvj96jniWRV for <>; Wed, 22 Apr 2020 19:27:14 -0700 (PDT)
Received: from ( [IPv6:2001:558:fe21:29:69:252:207:40]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by (Postfix) with ESMTPS id 4422B3A0E65 for <>; Wed, 22 Apr 2020 19:27:13 -0700 (PDT)
Received: from ([]) by with ESMTP id RRPIjhkpwLoTbRRa4jA1Cd; Thu, 23 Apr 2020 02:27:12 +0000
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed;; s=20180828_2048; t=1587608832; bh=3sFtLjOVCYdjZl4Ph8gkrusNWyo8FwFMUbqpLqdklmg=; h=Received:Received:Received:Received:From:To:Subject:Date: Message-ID; b=gtgGM57IvVqu/+Sy6naYdRlKP8wlCUkak/svX1VP2OHTXmEKcFOFTKFzlSHewEEDt izYEdc9KHbMrH9Lk2UX2AHh2qI3u1HkReKzirF7i/jXZma6SPMpd97LesVJzlSAIcr 6qAFgRRn5B6usrUTHl02wfET7L+OqNeWobqkj2CrF+9pbZbp0juVZrvvU0tG5iBmJC DkGrN0y1x2oUj0jjotM337ytk0IwxQdxDoiyMW384phlzr9LXWKLYLdZp066kFfzYS do9+QH+u2YlX/zk+Mef5Pw9uC0VbnZPBSM0Rcepx53u6jpbNdqtHaOLxTdxEIHHMd3 WWukiUb/uoAnQ==
Received: from ([IPv6:2601:192:4a00:430:222:fbff:fe91:d396]) by with ESMTPA id RRa2jJry8TY9rRRa2jCq4Q; Thu, 23 Apr 2020 02:27:11 +0000
X-Xfinity-VMeta: sc=-100.00;st=legit
Received: from ( []) by (8.14.7/8.14.7) with ESMTP id 03N2R9JS005334; Wed, 22 Apr 2020 22:27:09 -0400
Received: (from worley@localhost) by (8.14.7/8.14.7/Submit) id 03N2R8pI005312; Wed, 22 Apr 2020 22:27:08 -0400
X-Authentication-Warning: worley set sender to using -f
From: (Dale R. Worley)
To: Gunnar =?utf-8?Q?Hellstr=C3=B6m?= <>
In-Reply-To: <> (
Sender: (Dale R. Worley)
Date: Wed, 22 Apr 2020 22:27:07 -0400
Message-ID: <>
Archived-At: <>
Subject: Re: [AVTCORE] Multi-party real-time text requiring new RTP payload type
X-Mailman-Version: 2.1.29
Precedence: list
List-Id: Audio/Video Transport Core Maintenance <>
List-Unsubscribe: <>, <>
List-Archive: <>
List-Post: <>
List-Help: <>
List-Subscribe: <>, <>
X-List-Received-Date: Thu, 23 Apr 2020 02:27:18 -0000

I assume that there's a good reason why the case of redundant
transmission of multi-party text isn't done by suitably interleaving the
redundant packets of the serveral text sources (which can be separated
by their SSRC values).  I can't remember if this is a violation of the
RTP rules, or perhaps it's just inefficient.  But a quick read of the
draft didn't mention why this approach doesn't work, and it seems like
it would be a useful note to the reader.