This guide provides the basic registration and route configuration process for SIP.US with consideration to changes in 3CX Version 18. Please note this guide is for new installs of 3CX. Screenshots are included throughout to demonstrate the process.
1. Log in to the Admin Console to access the 3CX configuration menu.
Registration
2. Navigate to the “SIP Trunks” menu on the left menu column and click "Add SIP Trunk." Select “US” as the Country and “SIP.US” as the Provider. Enter your SIP trunk number in the “Main Trunk Number” field and click "OK".
3. On the “General” tab of the SIP trunk configuration, your “Registrar/Server/Gateway” host should auto-populate with “gw.sip.us” with the “Auto Discovery” box checked. Below in the “Authentication” section, enter your SIP trunk number as the “Authentication ID” and your “Trunk Password” (found in the SIP.US Customer Portal under "SIP Trunking" --> "SIP Trunks") as the “Authentication Password”.
4. Select the “Options” tab in the SIP trunk configuration. Scroll down to “Advanced” and confirm the template has “Alternative Proxy” configured with “gw5.sip.us” in the field.
5. Select the “Inbound Parameters” tab in the SIP trunk configuration. Change the “CalledNum” parameter from “To: User Part” to “Request-Line URI: User Part.” Verify that "CallerNum" is set to "Contact: User Part" and "CallerName" is set to "From: Display Name". Click "OK" to save the configuration.
6. Back in the main SIP trunk status menu, the SIP trunk you just configured should now show as green to indicate it’s registered with the SIP.US gateway. You may also confirm the connection status in the SIP.US customer portal by navigating to "SIP Trunking" > "SIP Trunks" and clicking "View Trunk Registration Status".
Outbound Routes
The next step is to configure outbound calling. SIP.US requires all North American numbers to be dialed in an 11-digit format (see Setting Up Outbound Calling for more info on this topic). Select “Outbound Rules” in the left menu and click “Add.” We will be adding three separate rules as described below:
NOTE: Remember to set the "Route" to the SIP trunk you created and also populate the "Outbound Caller ID" field for each rule.
7. For general dialing of 11-digit North American numbers, this route will take the number and route it directly to SIP.US. Set "Calls to Numbers with a length of" to the value "11".
8. For general dialing of 10-digit North American telephone numbers, this rule will route dialed numbers with a length of 10 digits and add a "1" to the front of the dialed number string. Then it will route to SIP.US as a total of 11 digits. For this rule, add "10" to the "Calls to Numbers with a length of" field and add the "1" in the "Prepend" field.
9. For Emergency Calling, this route will take all calls that begin with a "9" and are 3-digits in length. These calls will then be routed to SIP Trunk. Add the "9" to the "Calls to numbers starting with prefix" field and "3" to the "Calls to Numbers with a length of" field.
IMPORTANT: Add your Enhanced DID as the "Outbound Caller ID" for E911 calling. See the article E911 - Important Information for more info on this subject.
10. For International Calling, this route will take all calls that begin with "011" dialed, which is the International Exit code, and then send the calls to SIP.US after stripping the first digits (011) from the number string. Add "011" to "Calls to numbers starting with prefix" and "3" to the "Strip Digits" fields.
NOTE: See Setting Up Outbound Calling for more information on setting up international calling.
Inbound Routes
11. For inbound call routing, you will first need to obtain DID (Direct Inward Dial) numbers from SIP.US. This can be done in your Customer Portal under "SIP Trunking" --> "Order Telephone Numbers".
12. Once you have at least one DID, navigate to “SIP Trunks” in your 3CX. Edit your existing SIP trunk and select the “DIDs” tab. Click “Add Single DID” and enter your DID in an 11-digit format (i.e. 14045964200) and press ENTER. Click "OK" to save the changes.
13. Navigate to the “Inbound Rules” menu. Click the “Add DID Rule” button. Name the rule whatever you'd like, and verify that the correct DID is selected in the “DID/DDI” drop down. You may then use the “Route calls to” section to route inbound calls accordingly.
14. You will also need to ensure you have proper whitelisting set in the firewall to utilize the SIP.US service. Refer to Interconnecting with SIP.US for the full guidelines.
If you experience technical issues, please open a ticket by contacting the support team at support@sip.us or by calling 800-566-9810.