Because our VOIP phone system is on the internet there is no geographical restrictions. That means we can purchase a telephone number in any country, and forward the calls to our FreePBX system. Many countries allow anyone to purchase a number in that country, some, such as France, place restrictions that you have to prove you are a resident in that country.
We are going to set up a phone number on our system from UKDDI, currently you can get free UK geographic numbers here.
These telephone numbers are referred to as “DDI numbers” or “DID numbers” depending on which country you are from!
There’s no denying that setting up an inbound number can be frustrating sometimes. If you’re a SysAdminMan customer and have set up an inbound number that’s not working then just open a support ticket and we’ll have a look why.
If you’re not a SysAdminMan customer then there’s a couple of troubleshooting guides here –
Sending the call to our FreePBX system
There are 2 different ways this could happen and will depend on which call provider you are using. The 2 different methods are –
- Our trunk “registered” with the call provider. This tells the call provider what IP to send the calls to
- We enter a SIP URI in the call providers control panel telling it where to send the calls.
If you enter a SIP URI in your call providers control panel I suggest keeping the number the same as the DDI number you purchased. For example if you purchased the number 441604123123 and your FreePBX server IP address is 126.96.36.199 I would suggest setting to SIP URI to send the call to as SIP:[email protected]
Setting up our number in UKDDI
Here’s our number set up in UKDDI. We are entering a SIP URI and forwarding the call to our FreePBX server IP. Notice I am keeping the number in the SIP URI the same as my DDI number, that’s important later on
Setting up our trunks
The first thing we need to do is tell FreePBX/Asterisk what IP addresses incoming calls could be coming from. It is possible to allow all IP addresses to send calls to your system (anonymous SIP), but you don’t want to do that for security reasons.
You may not need to add additional trunks if you are using the same provider for incoming and outgoing calls.
I know that calls from UKDDI could come from one of 2 different IP addresses – 188.8.131.52 & 184.108.40.206, you may need to ask your call provider what IPs calls could come from.
We tell FreePBX/Asterisk to allow calls from these 2 IP addresses by setting up 2 SIP trunks
Setting up the Inbound Route
The Inbound Route is where we tell FreePBX what to do with a call that arrives at the system. As a first initial test I always put the call through to music-on-hold. This is better than going to an extension because if the call doesn’t work you won’t know if it’s an issue with the DDI number or the extension. This way we are just dealing with one of them.
Select Connectivity / Inbound Routes from the main menu
Now we create the inbound route. The description can be anything, the the DID Number should match the number we forwarded the call to. Setting the destination to “Terminate Call/Put caller on hold forever” will mean that the caller should hear the on-hold music. Don’t forget to Submit, then Apply the config
Once the inbound route is working correctly we can change the call destination to our extension.