Subject: [AVTCORE] I-D Action: draft-ietf-avtcore-rtp-circuit-breakers-09.txt

From: [email-masked]
Date: Fri, 06 Mar 2015 08:54:09 -0800

A New Internet-Draft is available from the on-line Internet-Drafts directories.
 This draft is a work item of the Audio/Video Transport Core Maintenance Working Group of the IETF.

        Title           : Multimedia Congestion Control: Circuit Breakers for Unicast RTP Sessions
        Authors         : Colin Perkins
                          Varun Singh
	Filename        : draft-ietf-avtcore-rtp-circuit-breakers-09.txt
	Pages           : 22
	Date            : 2015-03-06

Abstract:
   The Real-time Transport Protocol (RTP) is widely used in telephony,
   video conferencing, and telepresence applications.  Such applications
   are often run on best-effort UDP/IP networks.  If congestion control
   is not implemented in the applications, then network congestion will
   deteriorate the user's multimedia experience.  This document does not
   propose a congestion control algorithm; instead, it defines a minimal
   set of RTP "circuit-breakers".  Circuit-breakers are conditions under
   which an RTP sender needs to stop transmitting media data in order to
   protect the network from excessive congestion.  It is expected that,
   in the absence of severe congestion, all RTP applications running on
   best-effort IP networks will be able to run without triggering these
   circuit breakers.  Any future RTP congestion control specification
   will be expected to operate within the constraints defined by these
   circuit breakers.

The IETF datatracker status page for this draft is:
https://datatracker.ietf.org/doc/draft-ietf-avtcore-rtp-circuit-breakers/

There's also a htmlized version available at:
http://tools.ietf.org/html/draft-ietf-avtcore-rtp-circuit-breakers-09

A diff from the previous version is available at:
http://www.ietf.org/rfcdiff?url2=draft-ietf-avtcore-rtp-circuit-breakers-09

Please note that it may take a couple of minutes from the time of submission
until the htmlized version and diff are available at tools.ietf.org.

Internet-Drafts are also available by anonymous FTP at:
ftp://ftp.ietf.org/internet-drafts/

---

From: Magnus Westerlund <[email-masked]>
Date: Wed, 11 Mar 2015 16:50:09 +0100

WG,

I have reviewed the changes in this version and like to thank the
authors for the proposal on scaling the reporting interval. I do however
have some feedback.

1. Section 4.5:

The table contains two errors.

A. The CB_interval for Td=5.0 should be 3.

B. All values in the Time to trigger for Td values from 1.0 seconds and
larger is calculated without using the floor function.

2. Section 4.5:

   If the RTP/AVPF profile [RFC4585] or the RTP/SAVPF [RFC5124] is used,
   and the T_rr_interval parameter is used to reduce the frequency of
   regular RTCP reports, then the value Td in the above expression for
   the CB_INTERVAL parameter MUST be replaced by T_rr_interval.

I think that the correct thing to do is to say that for AVPF/SAVPF the
calculation of the CB_Interval shall be done using max(T_rr_interval, Td).

I do hope that other WG participants will review this. The change with
scaling the triggering is a significant change and you should evaluate it.

Cheers

Magnus Westerlund
(As individual)

On 2015-03-06 17:54, [email-masked] wrote:
> _______________________________________________
> I-D-Announce mailing list
> [email-masked]
> https://www.ietf.org/mailman/listinfo/i-d-announce
> Internet-Draft directories: http://www.ietf.org/shadow.html
> or ftp://ftp.ietf.org/ietf/1shadow-sites.txt
> 
> 

-- 

Magnus Westerlund

----------------------------------------------------------------------
Services, Media and Network features, Ericsson Research EAB/TXM
----------------------------------------------------------------------
Ericsson AB                 | Phone  +46 10 7148287
Färögatan 6                 | Mobile +46 73 0949079
SE-164 80 Stockholm, Sweden | mailto: [email-masked]
----------------------------------------------------------------------

---

From: Colin Perkins <[email-masked]>
Date: Mon, 23 Mar 2015 16:10:50 -0500

Magnus,

> larger is calculated without using the floor function.

Copy-paste bugs. Will fix.

> calculation of the CB_Interval shall be done using max(T_rr_interval, Td).

Makes sense.

Cheers,
Colin

-- 
Colin Perkins
https://csperkins.org/