Configuring DID with a VOIP Provider
In some cases when you have a VoIP Provider with DID/DDI, you might encounter a situation when the VoIP Provider will not allow a call to go through. In the 3CX Phone System server activity log we can see the following message: “Review Invite and Adjust Source identification”. You will need to configure the source identification section in your VoIP Provider. When using a VOIP provider with DID’s you need to set these up as follows:
- Select the VoIP Provider account node and click on the “DID” tab.
- Enter all the DID’s that you have been assigned under the “DID numbers” section. You may enter the DID numbers either as a complete number, for example *55114916 or *4916. All are valid options. Using a full phone number with area code should be avoided.
- Press “Apply”. The 3CX Phone System will create the DID’s and link them to the Main VoIP Provider Port/Trunk Line.
- Select the “Source ID” tab.
- Make sure “Source Identification by DID” is enabled
- In the “SIP Field containing DID Numbers” select “To:User Part“. (This is the most common location in the SIP Message where the DID will be put). Test the inbound call routing. If the call does not route as expected, in the “SIP Field containing DID Numbers” select “Request Line URI: User Part”.
- Click on the “Add DID” button and select the DID’s you want to be matched (These are the DID’s you would have previously created in step 2).
- Click “Apply” to save your settings.