Hello All,
Iam new to the Voice Arena. Iam preparing for my CIPT...My question is in a Centralized Call Processing Model, with a MGCP Gateway at Remote Office, how would you configure your CallManager to reroute calls to your remote office via PSTN(when the WAN goes down)... I have read that AAR cannot be used when WAN link goes down....

Any help would be greatly appreciated.

Thanks in advance

Cheers

Hi keen

it depends on which version you have? It may not be possible on version 4.1.3 since call will go to voicemail right away if it is configured

However on CCM 6 it does have the option to forwarding calls to a PSTN number when some one dials an extension that is in unregistered mode

in DN Level you will see a setting call Forward Unregistered Internal set this to the PSTN number of the phone of the Remote site


Good luck

Hi Faisal,
Thanx for your response...So let me see if i understand what u have said...
So in the Multisite Centralised call processing model, when the remote office IP phone(s) gets unregistered from the call manager due to WAN outage(though it survives using SRST) and if someone from the Main Office calls teh remote office number, then the, "call Forward Unregistered Internal" setting for the Remote Site phone, forwards the call to the assigned Remote Site PSTN Number...


Thanks and I will try that ...

But at the same time, for this to work , i guess the Remote office numbering/dial plan should be DID enabled.... And secondly this configuration should be done for each and every remote site phone , so BAT is the answer to set this up....

pls correct me if my understanding is right.


Thanx a ton...

In case of WAN failure, an SRST referencing to the remote site Router should be configured so the phones know where to go in case they cannot reach the CUCM.

MGCP fallback needs to be configured also so it falls back to H323. At that point your Router will act as an H323 gateway to process and route your calls.

You'd need to have a complete set of dial-peers outgoing and incoming. You'd need to have Translations rule and translations profile in place so you can do digit manipulation, (Hint: your 4 digit extension numbers mean nothing to the PSTN world, they need the NPA-NXX aka fully qualified e.164 number to route the call).

You'd also need to have Class of Restriction (COR) in place appropriately so that all of a sudden your restricted phone is not able to dial International numbers and such.

By the way AAR feature is not designed to help out in the WAN failure scenario, rather help to route the call via PSTN when there is not enough bandwidth available (restricted by yourself between the two sites), you just enable it between the Headquarter and Branch sites for high availability.

I hope this clarifies you how things work, the rest is all the dirty work of tons of commands you'd need to put in to achieve this.

cheers.

Techguy.
Yes, It's all in the Voice! :)