Exception routing override

Exception Routing Override enables an MP to directly return an unknown subscriber message to the initiating node when normal routing fails (similar to what HLR's do when an IMSI or DN is not found in their database).

If normal routing fails and the Exception Routing Override option is not set, Exception Routing is performed regardless of whether the MP E.164 number is being set or not. The MP E.164 number must be set for Exception Routing Override to be performed. If the option is set and the MP E.164 number is missing, an event is issued on the GUI and exception routing is performed.

When an MP receives a message and the E.164 DN or E.212 IMSI is not found in MP’s database, the MP will first check if the Exception Routing Override flag is set and an E.164 number is configured in the MP Configuration table (see Exception routing configuration). If these conditions are met, the MP responds back to the MC with a well-formatted UDT message.

The following will apply to the response UDT message:

The UDT will contain a TCAP END message.
The DPC is assigned the OPC of the received request message.
The OPC is assigned the MP‘s self point code.
Called Party and Calling Party information will be transposed with one exception:
- The Calling Party address digit information is assigned the E.164 of the MP. See Exception routing configuration for the MP E.164 Configuration.
TCAP Component Type (Return Error).
The SCCP error flag in the header shall be set to TRUE.
The Dialog component of the TCAP message will be the basic Unknown Subscriber template with Destination Transaction ID recovered from the Originating Transaction ID of the initiating TCAP request.
- The dialogue PDU and version also need to be retrieved from the initiating TCAP request.
For the Component Portion of the TCAP message, the Invoke Id will need to be recovered from the initiating TCAP request.

Note: If the Exception Override Flag and/or E.164 number is not configured, then the MP will send the request message to Exception Routing.

Select Tekelec HLR Router > Configuration > Options.
TheTekelec HLR Router > Configuration > Options page appears.
Specify the exception you want to override and click the Exception Routing Override box.
Perform one of the following actions:
- Click the Exception Routing Override box to override the signaling exception routing.
- Click Exception Routing Override box to deactivate the exception routing override.

The exception routing activated or deactivated as indicated by the checkbox.