Use of IRR by Gateways

Rich Bowen rkbowen at CISCO.COM
Thu Mar 30 18:03:30 EST 2000

Paul (Long),

I think the issue is your recommendation to implementors:

Paul Long wrote:
> Reports from the field indicate that many (most?) EPs don't ever encode
> perCallInfo (Smith Micro does) and conversely most (all?) GKs don't ever
> look at the field anyway. IMO, this field is therefore useless. My
> recommendation to you is to simply ignore that field. Apparently IRR is
> _only_ used as a heartbeat indication.

The IRR may be used only as a heartbeat for terminals, but it is
a useful audit tool for gateways.  My recommendation to
implementors would be to *include* the perCallInfo, and leave it
up to the GK to decide whether or not it's important.  When the
standard is not clear, it's better for implementors to align
with the intention of the standard, if they can determine that
intention.  I think the intention is pretty clear in this case.

Paul Long wrote:
> Paul,
> I was explaining what the Recommendation actually requires and what vendors
> have implemented, not what "makes sense" or what the Recommendation should
> have said. While it may be a violation of the spirit of H.323 for an EP to
> never encode perCallInfo, it is clearly not a violation of the letter of
> H.323, and implementations have bore this out. If you think otherwise,
> please cite normative text.
> Paul Long
> Smith Micro Software, Inc.
> -----Original Message-----
> From: Paul E. Jones [mailto:paulej at]
> Sent: Wednesday, March 29, 2000 3:17 PM
> To: Mailing list for parties associated with ITU-T Study Group 16; Paul
> Long
> Subject: Re: Re: Use of IRR by Gateways
> Paul,
> I have to disagree.  If I have a GK that sends an IRQ with a specific CRV,
> it means that it wants call details about the call.  Why else would it send
> it?
> With a CRV=0, it wants all call details.  This included the perCallInfo, as
> well, and is important for the alternate Gatekeeper procedure (among other
> things).
> So, why is the field OPTIONAL in the ASN.1?  Because if the GK queries for a
> call that does not know about, it returns an IRR to the IRQ without any
> perCallInfo.
> Paul

Richard K. Bowen                       Cisco Systems, Inc.
rkbowen at                      Research Triangle Park, NC

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