Configuring China Mobile with 3CX
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China Mobile is one of the largest Chinese telcos. They offer IMS SIP trunks under various provinces, the one that has been tested with 3CX for which the below documentation applies is :
- China Mobile IMS - Hangzhou province
Before configuring the SIP trunk it is required to go through the following checklist and make changes where necessary:
- NAT (when used) created to 3CX
- Firewall Checker passed
- Firewall SIP ALG checked and if present disabled
Further setup information can be found in our Academy: 3CX Academy Basic course
Some providers gained support and compatibility with 3CX on a specific product version. It is advisable to always run the latest version of 3CX to ensure ongoing compatibility.
Minimum 3CX Version: 3CX Phone System 15.5 SP2
Below is a short overview of the provider's capabilities and services and whether they’re supported or not:
- CLNS (Clip No Screening): No
- Catch All Routing: Yes, static SI per trunk
- Fax in T38: No
- CLIR (Number Suppression): No
- DTMF via RFC 2833: Yes + In-Band
- Codec Order: G711A
- NAT: Yes
Configure the Trunk with 3CX
You will need to adjust the Registrar hostname and Outbound Proxy IP with the values China Mobile provided.
After, in the “Authentication” section enter your:
- Main number in the “Authentication ID” field.
- Password in the “Authentication Password” field.
- “Main number” “@” ”Registrar hostname” in the “3 Way Authentication Password” field.
Then, specify the number of SIM Calls below as per your contract.
When configuring China Mobile SIP Trunks in 3CX, all numbers should be entered in E164 international format.
Outbound Caller ID
China Mobile does not support Clip No Screening, meaning that you can present only your own numbers. Those must be input in E164 format.