The Barracuda Phone System is a SIP-compliant IP-PBX and can communicate with other SIP-compliant endpoints and servers. When two SIP servers need to communicate there are requirements that must be met on each server. For example, will the servers use IP authentication or digest authentication? Will the servers register with one another? The answers depend on your deployment scenario. IP-based authentication is usually simpler but should be employed only when you have control over the whole network being used. The Barracuda Phone System does not require the other server to register, but some other servers may require the Barracuda Phone System to register with them.
This example uses simple IP-based authentication. Use a gateway definition for routing calls to the other server and use a site definition to route inbound calls from the other server. For the dial plan, use 31xx as the extension numbers that route to the remote server.
Configuring Outbound Calls
Create a new gateway account. Refer to Adding VoIP/SIP Providers. The Host address is the IP address of the remote server. Specify a Username, Authentication Username, and Password for the other server. (If the far end server allows anonymous inbound calling, just fill in these fields with dummy values.) For this example name the gateway Remote SIP Server.
Next, create a new call type using Providers > Call Routing > Manage Call Types > Add a Call Type. Use these settings:
- Call Type Name: Remote 31xx (Use something meaningful for your setup)
- Match Condition: ^31\d\d$
- Route Type: Internal
Add a new route entry using Providers > Call Routing and Add a routing entry with these parameters:
- Call Type: Remote 31xx (or whichever name you used in the previous step)
- Destination: Remote SIP Server (or whichever name you gave to your new gateway)
Now the Barracuda Phone System can send calls to the remote server. If the calls do not route properly, confirm that the remote server is configured to receive calls from the Barracuda Phone System IP address. Also, if you use digest authentication, confirm that the authentication user name and password are correct.
Configuring Inbound Calls
Inbound calls can be handled by adding a Site. Navigate to Configuration > Sites and define a new site by Subnet or IP addresses. Name the site, and for the CIDR, use the IP address of the remote server followed by /32. For example, if the remote server is 192.168.2.10 then the CIDR would be: 192.168.2.10/32.
Select Define Site to save your site settings. Calls from the far end server will now route to the Barracuda Phone System.