Call Forking Based on Active Directory User Attributes

This article describes the steps necessary to configure the SBC Edge (SBC) to fork calls using User attributes stored in Active Directory by employing the SBC's Transformation and Call Forking features. 

In this example we use a PSTN - SBC - Lync/SBA environment, and we want to route all calls from PSTN to Lync clients to a Lync user, and we want them forked to the same Lync user's mobile and IP phone numbers using attributes from the user's AD record.

Call Forking Logic Overview

A PBX phone 6222 dials the Lync/SBA user's extension number 1005, resulting in the call landing on the inbound ISDN Signaling Group on the SBC. The call is then routed using the relevant Call Route Table triggering the relevant sequence of events:

1. In the Call Route Entry, where the call forking option is enabled, the number is normalized first using the relevant call Transformation Table, and then gets routed to the relevant outbound Signaling Group (in this exercise, the call goes to a Lync user using by a SIP SG).
2. The call continues with the next Call Route Entry, where the call forking option is also enabled. The number is normalized using the relevant Transformation Table using the cached Active Directory user attributes, resulting in the call to get routed to the relevant outbound signaling group (in this exercise, the call goes to outbound SIP signaling group to reach out to Lync/SBA user's IP phone).
3. Lastly, the routing continues with the next Call Route Entry (where the call forking option is disabled, denoting the last forked call leg). The number is normalized using the relevant Transformation Table using the cached Active Directory user attributes, and the call is routed to the relevant outbound signaling group (in this exercise call goes to outbound ISDN signaling group to reach out to Lync/SBA user's mobile device).

Before You Begin

Before you begin, you'll need to verify the following:

Verify the Call Forking License

1. In the SBC WebUI, click the Settings Tab.
2. In the left navigation pane, go to System > Licensing > Current Licenses.
3. Verify that Call Forking Feature is licensed as shown below.

Verify Call Forking License

 

Verify Lync/SBA Configuration and AD Integration

Before you begin, make sure the SBC is configured and integrated with Lync/SBA as described in Call Routing Based on Active Directory User Attributes. In addition to this, verify the SBC Active Directory settings:

Related Information

• Calling Party: PSTN phone 6222
• Called Party: Lync client with following AD profile:
  • userPrincipalName: SBAagent1@SBCDEMO.Sonus
  • ipPhone: 9911
  • mobile: 6228
  • msRTCSIP-Line: tel:+15102461005

SBC Configuration

In this section, we provide a step-by-step configuration walk-through enabling the use of Call Forking on the SBC:

Transformation Table Configuration

We will need three Transformation Tables created as shown below:

1. To SIP (Lync) transformation

   • Configure the "Calling Address/Number" and "Called Address/Number" translations

     SIP Transformation

     

2. To ipPhone attribute transformation:
   • Configure the "Called Address/Number" translations to normalize it to a "User Value" of AD attribute format (msRTCSIP-Line)

   • Configure the "User Value" translation to another AD attribute format "ipPhone"

     ipPhone Attribute Transformation

     

3. To mobile attribute transformation:
   • Configure the "Called Address/Number" translations to normalize it to a "User Value" of AD attribute format (msRTCSIP-Line)

   • Configure the "User Value" translation to another AD attribute format "mobile"

     Mobile Attribute Transformation

     

Call Routing Table

We create three entries in a Call Route used for ISDN to Lync calls, as shown below:

Three Call Route Entries

1. ISDN to Lync/SBA client route entry
   Note that Fork Call is set to Enabled, so for a particular call will continue.

   SBA: ISDN to SIP

   

2. ISDN to Lync/SBA client's ipPhone route entry
   Note that Fork Call is set to Enabled, so routing for a particular call will continue.

   To ipPhone

   

3. ISDN to Lync/SBA client's mobile device route entry
   Note that Fork Call is set to Disabled, so routing for a particular call will stop at this entry.

   To Mobile

   

    

Inbound ISDN Signaling Group

The ISDN signaling group for inbound calls is configured to use the relevant Call Routing Table (configured in the previous section):

Signaling Group Table