Including RTCP report packets in IRR

Even ,Roni roni.even at
Tue Dec 25 09:33:01 EST 2001

Having a solution for H.323 may not solve the problem. RTP & RTCP are used
also in other protocols like SIP. At the last IETF meeting (IETF-52) the
topic was discussed in the AVT WG. Maybe we can see what will happen there.
I would like to point out that SNMP can be used to get part of the
Roni Even

-----Original Message-----
From: Paul E. Jones [mailto:paulej at PACKETIZER.COM]
Sent: Monday, December 24, 2001 3:14 AM
To: ITU-SG16 at echo.jf.INTEL.COM
Subject: Re: Including RTCP report packets in IRR


I suppose this is probably in need of clarification, but the assumption was
that if the call contained an audio session, the audio element would be
included.  Likewise for video, etc.  Unfortunately, there are a few fields
in H.225.0 that are labeled as "OPTIONAL" in the ASN.1, so implementers
assume that semantically they're optional, but that's not the case.  We
don't want to change the syntax (since we don't want to mandate the
inclusion of a field when the call doesn't have a session of that type), so
I suppose it would be nice to see a proposal for clarification of this

One other thought about the RTCP stats is that we report them in the DRQ
rather than the IRR.  One problem with IRRs is that if they are sent too
frequently, an extremely busy system can get bogged down processing those
messages.  I imagine that you'd want to set the IRR timer somewhere outside
the length of an average call.  Doing so, though, would mean you never get
stats for the average call.  So perhaps DRQ alone (or in addition to) the
IRR is the right approach.


----- Original Message -----
From: "Paul Long" <plong at IPDIALOG.COM>
To: <ITU-SG16 at echo.jf.INTEL.COM>
Sent: Tuesday, December 18, 2001 10:42 AM
Subject: Re: Including RTCP report packets in IRR

> Paul,
> Please note though that an EP is not required to include any media info in
> perCallInfo, i.e., audio, video, and data. I imagine that this was an
> oversight, but we ought to explicitly require v5+ EPs to report all
> currently active media sessions, including RTP.
> Paul Long
> ipDialog, Inc.
> -----Original Message-----
> From: Mailing list for parties associated with ITU-T Study Group 16
> [mailto:ITU-SG16 at echo.jf.INTEL.COM]On Behalf Of Paul E. Jones
> Sent: Tuesday, December 18, 2001 3:07 AM
> To: ITU-SG16 at echo.jf.INTEL.COM
> Subject: Re: Including RTCP report packets in IRR
> I completely support your idea.
> pj
> ----- Original Message -----
> From: <frank.derks at PHILIPS.COM>
> To: <ITU-SG16 at echo.jf.INTEL.COM>
> Sent: Monday, December 17, 2001 2:42 AM
> Subject: Including RTCP report packets in IRR
> > Dear all,
> >
> > RTP's specification mandates that the RTP ports, for a given
> > source/destination, are "co-located" with the RTCP ports. This
> > means the the report information about the RTP streams flow
> > between the communicating endpoints. Although this mode of
> > operation is intentional, it does make it difficult for 3rd
> > parties to monitor the statistics as perceived by the endpoints.
> > This can be particularly useful for network management where
> > one would like to be able to monitor whether the network
> > provides adequate quality.
> >
> > On way to access the RTCP information would be to route all the
> > RTCP traffic through some entity, but this also means that the
> > RTP will have to follow the same path through the network. And
> > this is not desirable.
> >
> > For H.323 there would be the option to include the report packets
> > in the "audio" element in the perCallInfo element in the IRR
> > message. This would allow for a Gatekeeper to get a hold of these
> > "vital" statistics.
> >
> > Any views?
> >
> > Regards,
> >
> > Frank

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