Check_IMEI Message Handling

When the CHECK_IMEI message is received by the protocol, the IMSI (if active) and SVN are parsed from the MSU. Because different vendors place the IMSI information in different locations within the message, the decoder searches for the IMSI in multiple locations.

Once the required data is parsed, a lookup is performed in the RTDB to determine the response type for the IMEI/IMSI combination.

The appropriate response message is sent to the originating MSC.

Encoding Errors

When a response is generated, it is sent based on the CgPA information in the incoming message. However, some conditions may prevent DSR from generating the response. Most of the errors involve GTT on the CgPA; if the incoming data is Rt-on-SSN, the number of potential errors is much smaller.

Whenever an encoding error is detected, the response message is discarded.

Data Collection

See EIR Alarms and Measurements for a description of the measurements collected for the EIR feature.