msisdn number or msisdn definition

msisdn number or msisdn definition
MSISDN is a number uniquely identifying a subscription in a GSM or UMTS mobile network. Simply put, it is the telephone number to the SIM card in a mobile/cellular phone. The abbreviation has several interpretations, most common one being "Mobile Subscriber Integrated Services Digital Network Number".[1]
The MSISDN together with IMSI are two important numbers used to identify a mobile subscriber. The former identifies the SIM, i.e. the card that is inserted into the mobile phone, while the latter is used to route calls to the subscriber. IMSI is often used as a key in the HLR ("subscriber database") and MSISDN is the number normally dialed to connect a call to the mobile phone. A SIM is uniquely associated to an IMSI, while the MSISDN can change in time (e.g. due to number portability), i.e. different MSISDNs can be associated to the SIM.