Section: 2.2 Composition of IMSI
Content: IMSI is composed as shown in figure 1. Figure 1: Structure of IMSI IMSI is composed of three parts: 1) Mobile Country Code (MCC) consisting of three digits. The MCC identifies uniquely the country of domicile of the mobile subscription; 2) Mobile Network Code (MNC) consisting of two or three digits for 3GPP network applications. The MNC identifies the home PLMN of the mobile subscription within its country of domicile, or it identifies together with MCC and NID the mobile subscription's SNPN. The length of the MNC (two or three digits) depends on the value of the MCC. A mixture of two and three digit MNC codes within a single MCC area is not recommended and is outside the scope of this specification. 3) Mobile Subscriber Identification Number (MSIN) identifying the mobile subscription within a PLMN or SNPN.