IETF Logo Mail Archive

Re: [AVTCORE] RFC 8888 clarification: What does "active" mean?

Jonathan Lennox <jonathan.lennox42@gmail.com> Wed, 10 April 2024 17:01 UTC

Return-Path: <jonathan.lennox42@gmail.com>
X-Original-To: avt@ietfa.amsl.com
Delivered-To: avt@ietfa.amsl.com
Received: from localhost (localhost [127.0.0.1]) by ietfa.amsl.com (Postfix) with ESMTP id ACAC1C14F68B for <avt@ietfa.amsl.com>; Wed, 10 Apr 2024 10:01:57 -0700 (PDT)
X-Virus-Scanned: amavisd-new at amsl.com
X-Spam-Flag: NO
X-Spam-Score: -1.844
X-Spam-Level:
X-Spam-Status: No, score=-1.844 tagged_above=-999 required=5 tests=[BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, FREEMAIL_ENVFROM_END_DIGIT=0.25, FREEMAIL_FROM=0.001, HTML_MESSAGE=0.001, RCVD_IN_ZEN_BLOCKED_OPENDNS=0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001, URIBL_BLOCKED=0.001, URIBL_DBL_BLOCKED_OPENDNS=0.001, URIBL_ZEN_BLOCKED_OPENDNS=0.001] autolearn=ham autolearn_force=no
Authentication-Results: ietfa.amsl.com (amavisd-new); dkim=pass (2048-bit key) header.d=gmail.com
Received: from mail.ietf.org ([50.223.129.194]) by localhost (ietfa.amsl.com [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id cfH6J7H7lwdB for <avt@ietfa.amsl.com>; Wed, 10 Apr 2024 10:01:55 -0700 (PDT)
Received: from mail-pf1-x42e.google.com (mail-pf1-x42e.google.com [IPv6:2607:f8b0:4864:20::42e]) (using TLSv1.3 with cipher TLS_AES_128_GCM_SHA256 (128/128 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by ietfa.amsl.com (Postfix) with ESMTPS id 8FF1EC14F605 for <avt@ietf.org>; Wed, 10 Apr 2024 10:01:55 -0700 (PDT)
Received: by mail-pf1-x42e.google.com with SMTP id d2e1a72fcca58-6ed267f2936so2896560b3a.3 for <avt@ietf.org>; Wed, 10 Apr 2024 10:01:55 -0700 (PDT)
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20230601; t=1712768515; x=1713373315; darn=ietf.org; h=cc:to:subject:message-id:date:from:in-reply-to:references :mime-version:from:to:cc:subject:date:message-id:reply-to; bh=3GgsdH5eobuVWkCAYs5X9Vcp2eJgcbsqb24ZDWeysT4=; b=ghX/czzf9hkft2S9Z9mwlvGFa/M+hju23LLtpv09vMV60UVvmVQ+NxP5XnbElMqkiQ s0zVexI8WPmEQ2n6p+GtqeK+lDLSwJCfVUHp/MQFxSoEcGJj7ht+hb47LfxF1brKP2vR 0f4ou8J11AZZWny7XmJWEY7A9WgTXNyE/s2ExmWK2+XRJAlgFgXZgiWyoosFjac8Xgo4 QgKkZWBAn7Jyqe5BzH4wvS/w1EiRwIfxI6yV8RgTyCoqJF42S4j88ldyFr9OEszBvGkG Ctvh+8bXUOoauM9zYU3Q2p+Xnk/MK4INz0PAD+QE9mCzPqoXyw8KtkbEClKpJd4MUT7Q 3NKA==
X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1712768515; x=1713373315; h=cc:to:subject:message-id:date:from:in-reply-to:references :mime-version:x-gm-message-state:from:to:cc:subject:date:message-id :reply-to; bh=3GgsdH5eobuVWkCAYs5X9Vcp2eJgcbsqb24ZDWeysT4=; b=LFQZch0vGTgn3crY9q5Mxkijp9o2W8I14v0vqXeSFb+5xcC5+ANKu0m04gBO+w88G+ RIAuQz+w9l951Eruvf/VcM4cRPvdgw1XmSFmDzGX0pvAqf7pz71WG0JVBVyIM1kAkvQN DNTZ6F15lsreQPkP9XlSAY3x5UVIvLpXgNNTk37zY+6nc3z4ODSQxY4pKUgTMSjgMVyz ZvWQjV6x5335tZ3Mknj5DGpYYsvWBPNipQh9wHHHTBbiywzjpey/RRxApGgRXCHms7lZ MJZvmPu98NyO0pRLfnmH7/6L2GL5rlWUoXjmoD8R7dVWQlr5ADHobpgU6bZwPbwyKhSz i9vQ==
X-Gm-Message-State: AOJu0YzylTTrx5fSv+mOovtEiIcnE2hrRrCi92ShVgzVF7eQGzCDPhea M1e1auAR/Yk0z8PZhWM0mah1prhUtiEbDUiOn46WaFGJ4oJzdcMJ4AN3d0RtPjIoAnzeluRJbe2 so0RbB+JR4Ziiv0ruTq8DCjNj3r8CHlZPVXk=
X-Google-Smtp-Source: AGHT+IHUawvVaggM3I0dpYs+Fq5tuyng9iKNZty52Aa8ADRqa70S6keZNQoHEPYa+37GIamAFRMDmZpZvGozei4Ki/o=
X-Received: by 2002:a17:90b:4a12:b0:2a4:92a3:d9dc with SMTP id kk18-20020a17090b4a1200b002a492a3d9dcmr2967382pjb.22.1712768514508; Wed, 10 Apr 2024 10:01:54 -0700 (PDT)
MIME-Version: 1.0
References: <f0e95d7c-0385-4206-9605-b3c61cd44b51@alvestrand.no>
In-Reply-To: <f0e95d7c-0385-4206-9605-b3c61cd44b51@alvestrand.no>
From: Jonathan Lennox <jonathan.lennox42@gmail.com>
Date: Wed, 10 Apr 2024 13:01:42 -0400
Message-ID: <CAKx+b+YdRxHOFOERNSN1j6dGcpJkY9STsHmpqCNRFJi66PQc3g@mail.gmail.com>
To: Harald Alvestrand <harald@alvestrand.no>
Cc: avt@ietf.org
Content-Type: multipart/alternative; boundary="000000000000e3d2440615c0feeb"
Archived-At: <https://mailarchive.ietf.org/arch/msg/avt/om7AGqJJyh5JKoeRRbKdY1wMq0c>
Subject: Re: [AVTCORE] RFC 8888 clarification: What does "active" mean?
X-BeenThere: avt@ietf.org
X-Mailman-Version: 2.1.39
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: Wed, 10 Apr 2024 17:01:57 -0000

Speaking as an individual, I'd say the second interpretation is the
intended one.

I haven't done the math, but the ratio of packet sizes reporting on traffic
from an SFU in a large conference would probably be even worse than the 1/3
that you estimate.

Since ccfb packets aren't meant to influence RTP membership state, I don't
think that including empty reports for non-current senders would send any
useful information.

On Wed, Apr 10, 2024 at 12:56 PM Harald Alvestrand <harald@alvestrand.no>
wrote:

> In looking at RFC 8888, we found an interpretation problem:
>
> "RTCP Congestion Control Feedback Packets SHOULD include a report block
> for every active SSRC."
>
> Two easily inferrable interpretations for "active":
>
> - Packets have been seen, and no BYE or timeout has occured
> - Packets have been seen since the last report was sent
>
> Now, the size of the reporting packet is very sensitive to this
> interpretation - back-of-the-envelope says that packets according to the
> last interpretation can be 1/3 of the packets according to the first.
>
> So - which interpretation is intended here, and why?
>
> Harald
>
> _______________________________________________
> Audio/Video Transport Core Maintenance
> avt@ietf.org
> https://www.ietf.org/mailman/listinfo/avt
>
>

v2.23.0 | Report a Bug | By Email