Skip to content

IP PBX Configuration - 3CXv14

3CX is a software-based, open standard, IP PBX that offers complete Unified Communications features, out of the box. SIP Trunk configuration instructions below apply to the following 3CX versions:

  • 3CX v. 14

Documentation is provided for scenario where 3CX server uses Static IP address on the public Internet and when Dynamic IP address is used.

Static IP address

3CX-sip-trunking-diagram-static-ip.png

Figure 8.1 3CX SIP Trunk - static IP address.


  1. Static IP address (a.b.c.d in our example above) of your 3CX server will be added to GoTrunk service IP ACL (Access Control List) and outbound calls coming from that IP address will be accepted without requiring any further authentication (SIP username and password). This is the most efficient way of authenticating SIP calls.

  2. Inbound calls to one of Telephone Numbers on your GoTrunk account will be sent directly to 3CX public IP address. Since the calls will be coming from known IP address of SIP Trunking service (q.x.y.z in our example above) 3CX will accept them without requiring any further authentication.


To configure 3CX server to work with GoTrunk SIP trunk using IP authentication the following changes are required:


3CX-sip-trunk-static-ip.png

Figure 8.2 3CX add SIP Trunk - static IP address.

Follow steps below to add SIP Trunk:

  1. Select SIP Trunks in left menu.
  2. Click Add Provider button in top toolbar.
  3. Enter GoTrunk into "Name of Provider" field.
  4. Select Generic from "Country" drop down list.
  5. Select Generic SIP Trunk from "Provider" drop down list.
  6. Click "Next" button.
  7. Enter eu.st.ssl7.net (for Europe POP) into "SIP server hostname or IP (or amn.st.ssl7.net to use North America POP).
  8. Click "Next" button.
  9. Enter your Customer ID into "External Number" field - it can be found in top right corner of your GoTrunk web admin panel.
  10. Enter 100 into "Maximum simultaneous calls" field.
  11. Click "Next" button.
  12. Select default destination for inbound calls.
  13. Click "Next" button to configure Outbound Routing rule. Note: example below is for illustration purposes only. You may want to create additional outbound routing rules as per your requirements.
  14. Enter Domestic calls via GoTrunk into "Rule Name" field.
  15. Enter 0 into "Calls to numbers starting with prefix"
  16. Select GoTrunk from trunk drop down list.
  17. Select 1 from "Strip digits" drop down list.
  18. Enter 44 (for United Kingdom, enter your own country telephone code as required) into "Prepend" field.
  19. Click "Finish" button.

Next follow "Inbound routing" instructions below.

Dynamic IP address

3CX-sip-trunking-diagram-dynamic-ip.png

Figure 8.3 3CX SIP Trunk - dynamic IP address.


  1. For outbound calls from 3CX to GoTrunk SIP Credentials (SIP username and password) authentication is used.

  2. For inbound calls to one of Telephone Numbers on your GoTrunk account to work 3CX needs to Register with GoTrunk service (and periodically refresh registration in case IP address changes). Calls will be sent to IP address which was sent in the most recent 3CX Registration. Since the calls will be coming from known IP address of SIP Trunking service (q.x.y.z in our example above) 3CX will accept them without requiring any further authentication.

To configure 3CX server to work with GoTrunk SIP Trunk using SIP Credentials authentication the following changes are required:


3CX-sip-trunk-dynamic-ip.png

Figure 8.4 3CX add SIP Trunk - dynamic IP address.

Follow steps below to add SIP Trunk:

  1. Select SIP Trunks in left menu.
  2. Click Add Provider button in top toolbar.
  3. Enter GoTrunk into "Name of Provider" field.
  4. Select Generic from "Country" drop down list.
  5. Select Generic SIP Trunk from "Provider" drop down list.
  6. Click "Next" button.
  7. Enter eu.st.ssl7.net (for Europe POP) into "SIP server hostname or IP (or amn.st.ssl7.net to use North America POP).
  8. Click "Next" button.
  9. Enter your Customer ID into "External Number" field - it can be found in top right corner of your GoTrunk web admin panel.
  10. Enter your Outbound SIP Username into field "Authentication ID".
  11. Enter your Outbound SIP Password into field "Authentication Password".
  12. Enter 100 into "Maximum simultaneous calls" field.
  13. Click "Next" button.
  14. Select default destination for inbound calls.
  15. Click "Next" button to configure Outbound Routing rule. Note: example below is for illustration purposes only. You may want to create additional outbound routing rules as per your requirements.
  16. Enter Domestic calls via GoTrunk into "Rule Name" field.
  17. Enter 0 into "Calls to numbers starting with prefix"
  18. Select GoTrunk from trunk drop down list.
  19. Select 1 from "Strip digits" drop down list.
  20. Enter 44 (for United Kingdom, enter your own country telephone code as required) into "Prepend" field.
  21. Click "Finish" button.

Next follow "Inbound routing" instructions below.

Inbound Routing

3CX-inbound-routing.png

Figure 8.5 3CX add Inbound routes.

For each of the Telephone Numbers on your GoTrunk account follow steps below to add Inbound route:

  1. Select Inbound Rules in left menu.
  2. Click Add DID button in top toolbar.
  3. Enter your Telephone Number into field "DID/DDI number/mask".
  4. Select GoTrunk in "Available ports" list.
  5. Select destination for your Telephone Number.
  6. Click "OK" button.