How to know if subscriber has data service access or not

Huawei library on HLR describe it very well that if a subscriber HLR parameter NAM has a value of MSC then it means that the said subscriber has only access to CS(Circuit Switch) network. If it has a value to SGSN then the customer has access to PS (Packet Switch) network. And it it has a value of BOTH then it means the customer has access to both CS &PS network.

This information/explanation is particularly useful when you solve customer complain. Sometimes customers complain, he/she cannot LU in PS. Then you can check this HLR parameter.