Information Request
A attendant periodically sends an IRQ to anniversary registered endpoint to verify it still
exists, as illustrated in Figure 8-7. To absolute traffic, the IRQ is beatific alone if the endpoint
does not accelerate some added RAS cartage aural a assertive interval. If an IRR is not received
after an IRQ is sent, the allotment is age-old out of the system.
Figure 8-7 Advice Request
456 Authorized Self-Study Guide: Cisco Voice over IP (CVOICE)
Gateway A
Gatekeeper
V
IRQ IRR
Note In addition, during calls, endpoints are instructed to accelerate alternate unsolicited
IRRs to address their alarm state. Cisco endpoints (proxies and gateways) accelerate IRRs whenever
a accompaniment alteration exists, so that accounting advice is accurate.
Whenever an IRR is sent, the age tags on the allotment advice for the endpoint
are refreshed. In addition, if the IRR contains Cisco accounting advice in its
nonStandardData field, this advice is acclimated to accomplish authentication, authorization,
and accounting (AAA) transactions.
To ensure that accounting is as authentic and simple as possible, the attendant will confirm
IRRs from Cisco gateways and proxies by sending an ICF. If the aperture or proxy
does not accept the ICF, the IRR should be resent.
The RAS cachet advice letters accommodate IRQ, IRR, IACK, and INAK.