Cisco "External Phone Number Mask" assistence needed

We are running a Cisco CM 4.0 phone system. We recently added another site office to outr network that is in another state. That remote office is using a Cisco 881 voice gateway router with two VPN tunnels for the network VLAN and the Voice VLAN. That all seems to work just fine. However, we would like the caller ID from that remote office to have a local presence. I've tried using the "External Phone Number Mask" field in call manager but it still just shows our main line at the corporate office for the caller ID. It's important that we can spoof the caller Id for to show a local presence for that site office as well as for any potential 911 calls. Any help on this would be greatly appreciated.

Who is Participating?
I wear a lot of hats...

"The solutions and answers provided on Experts Exchange have been extremely helpful to me over the last few years. I wear a lot of hats - Developer, Database Administrator, Help Desk, etc., so I know a lot of things but not a lot about one thing. Experts Exchange gives me answers from people who do know a lot about one thing, in a easy to use platform." -Todd S.

luc_roySystem AdminCommented:
This is a common problem with VOIP.  The recommended method is a local 911 land line at each office.  You can connect it via an ATA ($30-$40) so all 911 calls stay local and the fire / cops show up to the correct building.

The problem with setting it up via the remote office is if the line goes down you lose you 911 ability.

Experts Exchange Solution brought to you by

Your issues matter to us.

Facing a tech roadblock? Get the help and guidance you need from experienced professionals who care. Ask your question anytime, anywhere, with no hassle.

Start your 7-day free trial
There are several places that it can be getting the corporate number:

From the Gateway config
From the Route Pattern
From the DN config
From the Carrier

I wouldn't do the 911 because what happens if the tunnels go down?  I would put it on a pots line connected to the FXO port on the Cisco 881 at the site and don't worry about it.
Also keep in mind that I ran into a problem once where the carrier would only accept certain Caller IDs and others were denied the ability to call out.
crdixonAuthor Commented:
We do not have any analog lines there - only the internet circuit as we are running this remote site office as bare bones as possible. So if the tunnel goes down it won't really matter.  In the Route Pattern, it appears that "Calling Line ID Presentation" and "Calling Name Presentation" are all set to default. In the Gateway, I see our main line number in the "Caller ID DN". If that is left blank, does it then pick it up from the individual line configuration from the "external phone number mask" field ?
The Ultimate Tool Kit for Technolgy Solution Provi

Broken down into practical pointers and step-by-step instructions, the IT Service Excellence Tool Kit delivers expert advice for technology solution providers. Get your free copy for valuable how-to assets including sample agreements, checklists, flowcharts, and more!

crdixonAuthor Commented:
Additional info: I fear that the telco on this might be my stumbling block. It's a T1 PRI circuit through Cox at the headquarters location where the Call Manager servers are.
luc_roySystem AdminCommented:
how is the T1 connected to your network?  If it's not connected you can put a T1 card in a router and connect it.
crdixonAuthor Commented:
The PRI T1 comes into a Cisco 2811 voice gateway router
Is the number that you are trying to spoof part of your DID listing through the PRI?  Often the telco will only allow the outbound caller id to be changed as long as it's one of the DID configured for that PRI.  This however does not sound like the case, my guess is that this caller id info is being taken from either the gateway or the route plan which states regardless of what external mask the call manager is sending the outbound caller id should be a specif DID.
crdixonAuthor Commented:
No it is not. The number to be spoofed is a virtual vanity number in the same area code that the out of state remote office is in. That number is being forwarded to one of our DiD's via the telco.
you have to check with PSTN provider if they will allow you to play with the callerd ID usually they will not allow it. if you want to check just configure "Calling Line ID Presentation" under the route pattern to be restricted after that if the caller id will be private on the phone(receiver) then we can start solving your problem.

It's more than this solution.Get answers and train to solve all your tech problems - anytime, anywhere.Try it for free Edge Out The Competitionfor your dream job with proven skills and certifications.Get started today Stand Outas the employee with proven skills.Start learning today for free Move Your Career Forwardwith certification training in the latest technologies.Start your trial today
IP Telephony

From novice to tech pro — start learning today.