Background:
The customer’s 3CX is deployed on Google Cloud. Due to infrastructure issues, there is no broadband and PSTN line access in the local area, 4G routers are used to solve network problems, and GOIP gateways and SIM cards are used to solve communication problems. Due to the use of 4G routers, there will be multiple NAT problems in the devices behind the router, which will result in the GOIP gateway not being able to register to the 3CX in the cloud. This time we need to use our 3CX SBC. In this document, we will introduce Use 3CX SBC to solve the GOIP Gateway register issue.
3CX includes the 3CX Session Border Controller (SBC) which allows easier bridging of remote 3CX instances and connection of remote extensions. The 3CX SBC combines all SIP (signaling) and RTP (media) VoIP Packets from one location and delivers them to and from another location (typically the PBX Server) using a custom TCP protocol. This simple concept allows 3CX to overcome firewall or telecom provider issues. The 3CX SBC can be used for the following reasons:
- Resolve issues of NAT Traversal at both the remote and the PBX location.
- Simplified Firewall configuration at both the remote and the PBX location.
- Overcome difficulties with ISPs that block VoIP Traffic based on port numbers.
- Allows VoIP-over-WiFi in some restricted locations, such as Hotel rooms.
- “Fixes” Firewalls that cannot handle VoIP traffic correctly or which are very problematic to configure correctly, such as Microsoft ISA Server
Note: Status information does not get carried through the SBC to the remote network as of yet. Make sure that the HTTPS ports you have chosen during the installation are open on the PBX server side.
Solution steps
Step 1, install and configure 3CX SBC
Click here to see how to install 3CX SBC (Session Border Controller), click here to see how to configure the 3CX Session Border Controller.
In this article, our 3CX SBC is installed behind the 4G router and the GOIP gateway is in the same network. Suppose the IP address of the SBC is 10.168.1.58, and the IP address of the GOIP gateway is 10.168.1.14.
Step 2, add a gateway on the 3CX server
Go to 3cx control panel-sip trunk, add Gateway, Select Brand as Generic, enter the Number of Physical PSTN Ports on device and the main DID number.
Enter the IP and port of the GOIP Gateway, and remember the Authentication ID and Authentication Password.
Next, establish an inbound rule, and assign the DID 8001 to the Specified extension. Here we select extension 000, as shown below:
Go to Outbound rule to add a rule for outbound call.
Step 3, GOIP gateway configuration
Enter the IP address of the GOIP gateway in the computer browser which is behind the 4G router. Go to the Basic VOIP registration gateway, the mode is single server mode, then fill in the authentication id and password obtained from 3CX, and fill in the registered address as the IP address of the SBC, as shown below:
The next configuration, call in, as shown below
Next, you can test the incoming and outgoing calls. The incoming call can go to the specified extension and the outgoing call is normal.