Configuring the SBC 1000 for FXS Calling

This article describes the steps necessary for configuring the Sonus SBC 1000 to route incoming PSTN calls to an FXS port. In the example below, ISDN/PSTN calls arriving with four digits are routed to an FXS port.

The process comprises four overall steps:

• Creating an FXS Signaling Profile
• Creating and configuring a CAS Signaling Group
• Adding and configuring a Transformation Table and Entry
• Adding a Call Routing Entry and resequencing it

Prerequisites

Software Version

Verify that your Sonus SBC 1000 is loaded with the correct boot image version and that your Sonus SBC 1000 base software version is at least version 2.0.0, build 108.

The FXS card does not function with older versions of the Sonus SBC 1000 firmware/software. Should you need to upgrade your Sonus SBC 1000 unit, you must follow the Sonus SBC 1000/2000 Upgrade Guide.

System Licenses

The Sonus SBC 1000 system must have the necessary licenses to make calls. In addition to CAS and DSP channels, and depending upon the types of calls, the Transcoding and SIP calls licenses may also be necessary as shown below:

Current Licenses

FXS Card State and Port Status

FXS Card State

• Check the state of the FXS card.

  • Verify that the state for the Telco Module(s) indicated in the Cards/Modules Status pane is Activated.

    Cards/Modules Status

     

Port Status

• Check the Port Status to verify that the FXS ports are functional.

  • Verify that the Admin State and Service Status for each port indicates Up as shown below.

    Port Status

    

FXS not Activated and Up? Did you upgrade the boot image and Sonus SBC 1000 base software versions as outlined above.

Verify the FXS Port Connections

Verify that your FXS devices are connected to the ports you plan to configure.
Later in this article, you will create a CAS Signaling Group and assign channels and ports, they must match the physical ports to which the FXS devices are connected. See the figure below.

Ports

Configuration

CAS Signaling Group and FXS Port configuration

1. Create an FXS Signaling Profile for CAS.

   Create FXS Signaling Profile

    

2. Create a CAS Signaling Group.
   Make sure to set the Channel Hunting to Own Number, otherwise the first free channel will answer every call (regardless of any other configuration settings).

   Create CAS Signaling Group

   

    

    

3. Create an Assigned Channel and apply the desired phone number to the corresponding FXS port.
   You may add all of the port/number combinations for FXS in a single Signaling Group.

   Create Assigned Channel

    

    

    

4. Verify that the CAS Signaling group is configured as shown below.

   Verify Configuration of CAS Signaling Group

    

    

    

5. Verify that the FXS-attached phone(s) now have dial-tone.

Telephony Routing configuration

In order to route incoming ISDN calls with 4 digits to FXS ports, you must create a Transformation table whose entry prepends +1510574. The resulting called number, +1510574xxxx, then matches the Channel Phone Numbers configured in the previous section.

1. Create a Transformation Table for the FXS calls called PSTN to FXS:

   Create Transformation Table

   

    

    

2. Create a Transformation entry to that table called PSTN to FXS Transformation.

   Create Transformation Table Entry

   

    

    

3. Add a call route table called From ISDN to SIP.

   Add Call Route Table

   

    

   Add a call route entry to that table which employs the transformation created in the previous step called PSTN to FXS.

   Create Call Routing Entry

   

    

    

4. Resequence the FXS call route.

   Resequence FXS Call Route

   

   

Calls should now work from ISDN to FXS.

Call Debugging Trace

The Sonus SBC 1000 logging trace produced was saved when making the FXS call - you can download it here.