use of analog lines, and fxo cards

Unanswered Question

I have a remote site that has NO dedicated Voice circuit. Their connection to the Call Manager cluster is thru an MPLS circuit.

This remote location has 1 analog line.

The HQ office is long distance and far away. When the remote location makes outbound calls, the remote location incur long distance charges when they dial a local number (this is without using the analog line).

On the outbound issue:

The remote location wants to dial all local calls from their 1 analog line. I can use the FXO card to do this right?

How about Inbound? Can I still use the analog line so that when people call the local number, it will ring at this remote site? I want it to ring the IP phones though. Can I still use an FXO card or do I need an ATA adapter? I hope this is clear enough.

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Nicholas Matthews Fri, 12/19/2008 - 09:40

Hi Julio,

This is done with the combination of route patterns and partitions. Make sure that the calling search space for the remote phones contains a route-pattern for the local dialing pattern within their search space. This local dialing pattern should point to the gateway you configure on CCM.

For inbound FXO calls, we have no idea what number is being called. Think about this - when you answer your phone at home, you have no idea what number the other person called. You just know your phone is ringing.

This means that you have to give it a 'default' or 'plar' number. This is usually a receptionist's DN or an autoattendant.

Basic steps:

Configure the router as H323/SIP/MGCP gateway

Add the gateway configuration in CCM

Add a route-pattern for local dialing, points to gateway. Put this is a new partition, 'remoteusers'.

Add a new CSS that includes 'remoteusers' and any other needed partitions.

Change CSS on phones to the new CSS

Yes. You would need an FXO card on a Cisco router that is registered to the CallManager as a Voice Gateway.

For inbound calls - if you have IP phones in the remote site, you can configure the voice port(FXO) with connection-plar statements to send the calls to the ip phone extension or use the attendant DN option if it is a MGCP gateway.

For outgoing - you need a Route pattern that sends calls out of the FXO ports that are registered as MGCP or H323 gateways. You would need to configure Partitions and Calling Search spaces to make sure that the IP phone reaches this Route pattern for outgoing and not the Main site's gateway.

you should not need an ATA other than if you want to use an analog phone/fax.

hope this helps,


One of the employees at the location looked online and noticed that Cisco made the ATAs. But these are only used when you still want to use an analog phone, correct?

So all I really need is the FXO card to be able to dial from the IP phones out the FXO port to make local calls with local charges, and to receive calls incoming thru the FX0 port and have it ring an IP phone.


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