Service key :
- Service key is used to identify the call type whether it is MO call or MT call.
- Service key is configured in HLR.
- It is available in IDP – Initial Detection Point.
- It is mapped with SCP GT.
- This field identifies the CAMEL service logic applied. Service key is defined in HLR as part of CAMEL subscription information.
The service key (SK) identifies the CAMEL service in the gsmSCF. The serving MSC or GMSC places the SK from O-CSI or T-CSI into CAP IDP. The SCP platform uses the SK to select the corresponding CAMEL service. A gsmSCF may host several CAMEL services. Since the O-CSI is specific for a subscriber, different subscribers may subscribe to different CAMEL services. When a subscriber has an O-CSI and a T-CSI, then these CSIs may contain different SK values. If a subscriber has O-CSI and T-CSI for a CAMEL service like VPN, then O-CSI and T-CSI typically have different SK values, but may have the same gsmSCF Address.
The service key has an integer value, in the range 0–2,147,483,647 (231 – 1). An operator may use any SK value within this range. An operator should aim to use unique SK values for all service that are hosted in the network. Unique SK values facilitate network monitoring and post-processing systems. Large SK values should be avoided where possible. The reason is that, according to the BER applied in GSM, large integer values take up more data transmission capacity than small integer values.
For example :
- 612 is MO call service key it is mapped with SCP GT – 4915210000200.
- 613 is MT call service key it is mapped with SCP GT – 4915210000200.