This article describes the steps necessary to configure SBC Edge to block collect incoming R2 calls. At the time this article was written, Brazil is the only country using this methodology for blocking collect calls.

Collect call blocking uses the R2 _Calling Party Category- to accomplish the block. For an incoming R2 call to the SBC Edge, the switch sends a called number and a Calling Party Category (CPC) of II-8. To accomplish the block, the SBC Edge must reject the called number that was received. Therefore, in advance, the SBC Edge is configured to reject certain number(s), and does so with a specific cause code. Instead of responding with a B-4 for call rejection, the SBC Edge responds with a B-7 to indicate collect call blocking.

In this section:

Before You Begin

Verify the following:

  • Confirm that the switch is configured to use CPC of II-8 to indicate collect calling.
  • Identify the number(s) on which SBC Edge will receive a collect call.
  • Follow the configuration steps below.

SBC Edge Configuration

This section assumes that the user is familiar with basic R2 call setup and routing in the SBC Edge.

The configuration process comprises four major actions:

  • Create and configure a transformation table and transformation table entry for collect call blocking.
  • Create a call action.
  • Create and configure an action set.
  • Create and configure a signaling group.

Transformation Table

Define, using regular expressions, the called number(s) that SBC Edge receives collect calls on. In the following example, any four digit number beginning with 8 (e.g., 8888) is matched to the regular expression defined in the Input Value Field (this number will be rejected by SBC Edge). The Input and Output Fields have the same value.

Create and Configure Transformation

 

To create and configure the transformation:

  1. Add a transformation.
  2. Name the table CollectCallBlock.
  3. Add an entry to the transformation table using the following information:
    1. Admin State: Enabled.
    2. Match Type: Mandatory.
    3. Input Field - Type: Called Address/Number.
    4. Input Field - Value: 8(\d{3})
    5. Output Field - Type: Called Address/Number.
    6. Output Field - Value: 8\1

Action Configuration

Define an action configuration which, if matched, acts as defined. In this case, the action configuration releases the call with a cause code of 1: Unallocated Number. This cause code MUST be defined.

Create Action Configuration

 

To create the action configuration:

  1. Add an action configuration using the following information:
    1. Description: CollectCallBlockAC.
    2. Action: Release Call.
    3. Q.850 Cause Code: 1. Unallocated Number.

Action Sets

Create an action set and define an entry to that action set which ties the transformation number(s) to the action configuration. Using this action set, if the SBC Edge receives any of the numbers defined in the transformation table above, it rejects the call with the cause code of 1: Unallocated Number.

Create Action Set and Add Entry

To create the action set and add the entry:

  1. Create an action set table using the following information:
    1. Description: CollectCallBlockAS.
  2. Add an entry to the table using the following information:
    1. Description: CollectCallBlock - action set.
    2. Execution Condition: Always.
    3. Transformation Table: CollectCallBlock.
    4. Action on Success: CollectCallBlockAC.
    5. Action on Failure: Continue.

R2 incoming Signaling Group

Assign the above action set in the incoming R2 Signaling Group definition for Action Set Table. This procedure assumes that the signaling group and the CAS signaling profile have already been created and configured. This procedure only adds the Action set to this predefined signaling group.

 

To add the action set to the signaling group:

  1. Modifythe existing incoming CAS-R2 inbound signaling group using the following information:
    1. Channels and Routing - Action Set Table: CollectCallBlockAS.