MSC/VLR Number

MSC Number

An MSC number identifies an MSC entity uniquely. It is coded in E.164 format.

Figure 1 MSC structure 

• A country code (CC) specifies the code of the country where an MSC is located according to the international PSTN numbering plan. CCs are allocated uniformly worldwide by the International Telecommunication Union - Telecommunication Standardization Sector (ITU-T). Its maximum length is three digits. For example, the CC of China is 86, and the CC of the Great Britain is 44.
• A national destination code (NDC), also called a mobile service access code, is a PLMN number. Its maximum length is three digits. NDCs are allocated uniformly within a country by the telecom management department.
• A locally significant part (LSP), it's allocated by carriers.

Detail:

A typical MSC number example is 86-139-0477.
Both operations PerformHandover and PrepareHandover use MSC numbers for addressing.

VLR Number

A VLR number identifies a VLR uniquely. In applications, the VLR and MSC are integrated, so the VLR number is set to the same value as the MSC number generally.