Intro… Up to this point, we’ve shown you how to DENY VoIP calls going across the WAN using various CAC methods, but we have yet to show you what to do with those denied calls…until now! In this Nugget, Jeremy breaks down Automated Alternate Routing (AAR), which allows calls to re-route over the PSTNwhen the WAN bandwidth is constrained.
What does AAR do?
- Fallback method for any call denied by CAC or RSVP
- Internal Directory Numbers Only
- Adds DN + External Phone Mask + AAR Source/Destination Group
This is NOT a failover mechanism.
The focus is on bandwidth.Centralised Model
Uses a Dial Prefix within the AAR Group to get the digits ‘PSTN friendly’
2 strategies for AAR setup…
Without Local RG/Globalisation…
AAR Groups with Prefixes for local areas and national areas
With Local RG/Globalisation…
It just works!! 🙂
- AAR Service Parameters (Disabled by Default clusterwide, Enable via CiscoCallManager service, AAR = Enable)
- AAR Group Configuration (Add Groups for Locations with Prefixes)
- AAR IP Phone Configuration (AAR Calling Search Space on DEVICE, AAR Group also added to DEVICE, under the LINE itself the External Phone Number Mask must be correct)
- *AAR Settings also present on the LINE to override External Phone Number Mask