Make Outbound Calls through a Designated 4G Trunk

When your TG400 gateway carries mobile (4G) trunks from more than one carrier, you can control which trunk each outbound call goes out on. Because many carriers offer plans with free or discounted calls to numbers on their own network, sending each call over the matching carrier’s trunk can noticeably reduce what you spend on calls. This page shows how to steer outbound calls to a chosen 4G trunk based on the number a user dials.

A 4G trunk is a line backed by a SIM card in the gateway, so calls placed over it use that carrier’s mobile network and its calling plan.

Note

Before you start, this setup assumes the pieces below are already in place:

• The TG400 gateway is connected to Cloud Voice over a SIP (Session Initiation Protocol, the signaling protocol that sets up calls) account trunk, so the two systems can pass calls to each other.
• The gateway has its 4G trunks online, one per carrier (in this example Trunk1 for Carrier A and Trunk2 for Carrier B).

Scenario

The steps below follow this example. Numbers that begin with 92 should leave over Carrier A’s trunk, and numbers that begin with 10 should leave over Carrier B’s trunk.

Dialed number	4G trunk	Carrier
Begins with 92	4G trunk 1	Carrier A
Begins with 10	4G trunk 2	Carrier B

Setting this up takes three stages:

1. Add an outbound route on Cloud Voice that hands the calls to the gateway.
2. Add two IP to Mobile routes on the TG400 gateway, one per carrier, that match the dialed number and pick the correct 4G trunk.
3. Place test calls to confirm each prefix uses the trunk you expect.

Step 1. Create an outbound route on Cloud Voice

An outbound route is the rule that lets your extensions dial out. Add one here so extensions can reach the outside world through the TG400 gateway.

1. Sign in to the Cloud Voice PBX (Private Branch Exchange, your phone system) portal and go to Call Control > Outbound Route, then click Add.

2. Configure these settings and leave the rest at their defaults:

   • Name: A label that helps you recognize the route.

   • Dial Pattern: Set the patterns to suit your needs. In this example, set Pattern to X., which lets users dial any number with no restriction.

     

     Note

     X. is deliberately broad. The per-carrier filtering happens later, on the gateway: the two IP to Mobile routes in Step 2 only accept numbers that begin with 92 or 10. A call that matches neither prefix has no gateway route to take and will not complete.

   • Trunk: Choose the SIP account trunk that connects to the TG400 gateway. In this example, choose the TG400 trunk.

     

   • Extension/Extension Group: Choose which extensions may dial out through this route. In this example, all extensions are selected.

     

3. Click Save, then Apply.

Step 2. Create two IP to Mobile routes on the gateway

On the TG400 gateway, create one IP to Mobile route for Carrier A and another for Carrier B. Each route matches a number pattern coming from Cloud Voice and sends the call out over the 4G trunk you assign to it.

1. Sign in to the gateway’s web interface and go to Gateway > Route Settings > IP to Mobile, then click Add IP to Mobile Route.

2. In the dialog that opens, configure the route using the values below, then click Save and Apply Changes.

   Setting	Description	Carrier A	Carrier B
   Simple Mode	Keep the basic settings or expand to show the full set.	No	No
   Route Name	A label that helps you recognize the route.	To-CarrierA	To-CarrierB
   Call Source	The SIP register trunk that connects back to Cloud Voice.	SIP Register Trunk - CloudVoice	SIP Register Trunk - CloudVoice
   DID Number	The pattern or number that matches the dialed number arriving from Cloud Voice.	92. to match numbers with the 92 prefix	10. to match numbers with the 10 prefix
   Call Destination	The 4G trunk the call goes out on.	Mobile - Trunk1	Mobile - Trunk2

   Caution

   Call Source is the gateway’s end of the same SIP link you selected as the Trunk in Step 1. Pick the register trunk that faces Cloud Voice on both routes. If it points at the wrong trunk, the calls arriving from the PBX will not match this route and will not go out.

   Caution

   The DID Number (Direct Inward Dialing) field is what each route uses to match the digits arriving from Cloud Voice, even though the term normally refers to an inbound number. Its pattern must match those digits, or the call has no route to take and the outbound call fails. To make a route accept any dialed number, set DID Number to a single dot (.).

   

   

Step 3. Place test calls

Dial a couple of numbers from a Cloud Voice extension and confirm each one leaves over the expected trunk:

• Dialing 921234567 sends the call out over 4G trunk 1.
• Dialing 108192837 sends the call out over 4G trunk 2.

Tip

If a test call does not go through, check that the number’s leading digits match one of the gateway’s DID Number patterns (92. or 10. in this example). A prefix that matches neither route has nowhere to go and the call fails.