Use of IRR by Gateways

Rich Bowen rkbowen at CISCO.COM
Wed Mar 29 09:40:40 EST 2000

> Mohamed Mustafa wrote:
> Hi All,
> H.323 requires all endpoints to transmit an IRR message in response to
> an IRQ message from a Gatekeeper (or some other entity), and also to
> send unsolicited IRR messages to the Gatekeeper's RAS address at
> specific intervals if requested by the Gatekeeper in the ACF or RCF
> messages.
> As I understand it, an endpoint must provide the details of all active
> calls in a single IRR response if the callReferenceValue field in the
> IRQ is set to 0. This is clearly not possible if the endpoint supports
> thousands (or even hundreds!) of simultaneous calls. Can anyone
> provide any guidance on what to do in such a situation?

H.323 v4 will contain a feature that will allow segmenting the
response into a series of IRRs.  This was approved at the
February meeting.  In the meantime, the standard does not
specify how to handle this situation.  I would be interested
in guidance in this case as well.

> Also, in the case of unsolicited IRR messages, I can't find anything
> which states that an endpoint must provide details of all active calls
> in each unsolicited IRR message. Therefore, an endpoint can either
> send a separate IRR message for each call, or it combine details of a
> number of calls (but not necessarily all) into each IRR message. Is my
> interpretation correct?

Since unsolicited IRRs are requested per-call via the irrFrequency,
my interpretation is that an IRR should report only the information
about the call for which it was requested.

That said, I think it would be a useful enhancement to find a
standard way to combine IRRs.

> Thanks,
> Mohamed

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

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