Re: [AVTCORE] comments on draft-ietf-avtcore-monarch-05

Hi, Charles:
----- Original Message ----- 
From: "Charles Eckel (eckelcu)" <eckelcu@cisco.com>
To: "Qin Wu" <bill.wu@huawei.com>; <avt@ietf.org>
Sent: Tuesday, November 08, 2011 1:21 AM
Subject: RE: [AVTCORE] comments on draft-ietf-avtcore-monarch-05

Hi Qin,

Please see inline.

> -----Original Message-----
> From: Qin Wu [mailto:bill.wu@huawei.com]
> Sent: Sunday, November 06, 2011 10:21 PM
> To: Charles Eckel (eckelcu); avt@ietf.org
> Subject: Re: [AVTCORE] comments on draft-ietf-avtcore-monarch-05
> 
> Hi, Charles:
> Thank for your valuable comments, please see my reply below.
> 
> Regards!
> -Qin
> ----- Original Message -----
> From: "Charles Eckel (eckelcu)" <eckelcu@cisco.com>
> To: <avt@ietf.org>
> Sent: Saturday, November 05, 2011 6:30 AM
> Subject: [AVTCORE] comments on draft-ietf-avtcore-monarch-05
> 
> 
> >I read the draft and have the following comments:
> >
> > Section 2 and 3 contain some definitions. Should we add definitions
> > there for additional terms, including interval metric, cumulative
> > metric, and sampled metric. There has been some debate on the
> > definitions of these on xrblock alias, and it would be good to have
a
> > consistent definition of these terms.
> 
> [Qin]: Fair, will add them into the update.
> 
> > Section 3 reads, " The Metric Block exposes real time Application
> > Quality information". Section 2 defined transport level, application
> > level, and end system metrics. As such, the use of "application
quality
> > information" seems too specific and limiting to me.
> 
> [Qin]: Correct, how about change as "QoS/QoE metric information".

Works for me.

> >
> > Section 5.2 read, There may be situation where more than one media
> > transport protocols are used by one application to interconnect to
the
> > same session in the gateway.  For example, one RTCP XR Packet is
sent to
> > the participating endpoints using non- RTP-based media transport
(e.g.,
> > using SIP) in a VOIP session, one crucial factor lies in how to
handle
> > their different identities that are corresponding to different media
> > transport."
> > Are we really expecting RTCP XR packets to be used outside of an RTP
> > session? Or are we trying to say there may be multiple RTP sessions
for
> > a given VoIP session, and there is a need to be able to correlate
the
> > RTCP XR packets from each of these RTP sessions with each other?
> 
> 
> [Qin]: Yes, this section focuses on describing correlation of RTP
session with Non-RTP
> session for monitoring purpose. You may read RFC5104 for an example
but not limited
> to this.

I was not able to find any description of correlating RTP and non RTP
sessions in RFC 5104.
RFC 5576 defines the "ssrc" SDP attribute, but even in that case, it
usage is defined for RTP-based media only. So am I still not sure of the
use case you have in mind here.

[Qin]: Sorry, I give you a wrong reference, it should be RFC6035.
In that case, we may need to consider how to deal different identities that corresponding to
both RTP session and SIP session. e.g., In SIP session, we may use global call identifier,
In RTP session, we may use SSRC, how to correlate with each other is the issue we may
need to look at. The solution is to use SDES item to associate SSRC of RTP stream with
global call identifier.

Thanks,
Charles

> > Nits:
> >
> > Section 4:
> > - change " may have different monitoring requirements, design large
> > block ..." to " may have different monitoring requirements.
Designing
> > large block ..."
> > - change " it is hardly to provide" to " it is hard to provide"
> > - change " block types For example" to " block types.  For example"
> > - change " consecutive metric interval" to " consecutive metric
> > intervals"
> 
> [Qin]: Fixed, thanks very much.
> 
> >
> > Thanks,
> > Charles
> >
> >
> >
> > _______________________________________________
> > Audio/Video Transport Core Maintenance
> > avt@ietf.org
> > https://www.ietf.org/mailman/listinfo/avt
> >