3CX: Connect a SIP Trunk

1. 1

   Log in to the 3CX PBX instance

2. 2

   Click SIP Trunks

   

3. 3

   Click Add SIP Trunk

   

4. 4

   Set the Country to Generic

5. 5

   Set the Provider to Generic SIP Trunk

6. 6

   Enter the 10-digit telephone number of your trunk, with no spaces or special characters in the Main Trunk No

7. 7

   Click OK

   

8. 8

   In the General tab, complete the following fields, leaving all others default

   1. 1
      Name: Enter a descriptive name for the trunk
   2. 2
      Registrar/Server/Gateway Hostname or IP: Enter the name of the SIP Trunk
   3. 3
      Auto Discovery: Unchecked
   4. 4
      Outbound Proxy: Enter the outbound proxy based on your primary core. If unsure, contact support

      • ATL: sbc-atl.ucaasnetwork.com
      • IAD: sbc-iad.ucaasnetwork.com
      • PHX: sbc-phx.ucaasnetwork.com
9. 9

   Number of SIM Calls: Set the number of simultaneous calls for the PBX you wish to allow

   

10. 10

    Type of Authentication: This will vary based on the kind of trunk you wish to configure. If an IP-based SIP trunk was set up initially, leave as Do not require - IP based. If an authentication-based trunk was configured, select Register/Account based

11. 11

    Authentication ID (aka SIP User ID): Enter the SIP User ID from the SIP trunk

    NOTE: This is not needed if an IP-based trunk was configured

12. 12

    Authentication Password: Enter the SIP User Password from the SIP trunk

    NOTE: This is not needed if an IP-based trunk was configured

    

13. 13

    Destination for calls during office hours: Choose where to route inbound calls during hours

14. 14

    Destination for calls outside office hours: Choose where to route calls outside office hours

    

15. 15

    Do not modify the outbound parameters

16. 16

    Click OK

17. 17

    Once the trunk is registered, 3CX should show a green circle to the left of the trunk.

    

    1. 1
       When adding two or more SIP trunks in 3CX, we recommend ensuring that the main trunk number assigned to one trunk is not duplicated in another. Having the same main number in multiple trunks can lead to call failures.
    2. 2
       Duplicate DIDs can be used only if one or both trunks are registration-based. However, if you're using IP-based trunks, duplicate DIDs are not supported and will cause issues.
18. 18

    For authentication-based trunks, the portal will then show the IP address of the registered trunk

    

In order to configure outbound calling through the SIP trunk, outbound rules will need to be added.

1. 1

   Navigate to Outbound Rules

   

2. 2

   Click Add

   

3. 3

   Set a Rule Name

4. 4

   Set Calls to Numbers with a length of to 10-11

5. 5

   Set Route 1 to the newly created trunk

6. 6

   Click OK

   

7. 7

   To configure international calling, click Add

   

8. 8

   Set a Rule Name

9. 9

   Set Calls to Numbers starting with prefix to 011

10. 10

    Set Route 1 to the newly created trunk

11. 11

    Click OK