I have a potential customer who wants to deploy CallManager 7.1 and IP phones on an internal network and then to route calls to the PSTN via a 2800 series ISR router (H.323) placed on the other side of a firewall.
Simple enough so far but the customer wants to deploy a Unity Express module in the 2800 ISR. CCM will use JTAPI to communicate with Unity Express and I am concerned whether this will work through the firewall.
The firewall will be a Juniper box and will not be NAT'ing addresses.
The Unity Express Design Guide makes the following statement
Java Telephony Application Programming Interface (JTAPI) communications does not currently work via NAT or firewall, so you cannot configue Cisco Unity Express on the other side of NAT from a Cisco CallManager controlling calls via JTAPI.
This seems a bit ambiguous. Does it mean that JTAPI will not work at all through a firewall or just that it will not work if NAT is configured.
If anyone has done this I would be interested in your comments.