Need to upgrade CCM system! Help!

[fillytown]

My company is looking to upgrade our CCM system infrastructure.

Our setup:

We have several sites at different locations which have high-speed VPN links to each other.

Currently, our CCM system is hosted at the main HQ location.  

Our Problem:

If the VPN link drops/dies, our phone system is unavailable.

Is there a way we can add infrastructure/software so that we can use a server on-site as a primary and the server at the HQ as a secondary?

We can't risk any more dropped calls since our VPN link goes into maintenance quite often.

Any advice would be greatly appreciated.

Filip Korngut

[Jaime Valencia]

Assuming you meet the requirements for clustering over WAN, install a SUB at that location.

[fillytown]

Do you mean sub-interface? 

How do you suggest it is done?

If not sub-interface, can you provide a link to what a SUB is?

Thank you.

[Jaime Valencia]

If you're an end user, get in touch with your support team for this, or reach a Cisco partner for assistance

http://www.cisco.com/c/en/us/td/docs/voice_ip_comm/cucm/srnd/collab10/collab10/models.html