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What is MSISDN?  

MSISDN stands for Mobile Station International Subscriber Directory Number. It is a unique identifier assigned to each mobile device in a GSM (Global System for Mobile Communications) network. The MSISDN is what links the subscriber and their mobile device and the network.  

What are the MSISDN numbers?

MSISDN numbers are made up of a country code, network code, and a unique subscriber number. The subscriber number is typically 10 digits long, but it can vary in length depending on the country. 

How does it work?

When a user makes a call or sends a message, the MSISDN is used by the mobile network to identify the mobile device and route the call or message to the correct destination. The MSISDN is stored in the Home Location Register (HLR) and Visitor Location Register (VLR) of the mobile network operator. These registers keep track of the location of the mobile device and ensure that calls and messages are delivered to the correct location. 

What is the difference between MSISDN and IMSI?

It is important to note that MSISDN is not the same as IMSI (International Mobile Subscriber Identity). IMSI is a unique identifier assigned to the SIM card in a mobile device. While MSISDN is tied to the mobile device, IMSI is tied to the SIM card. The key difference between these two identifiers is that MSISDN is used to identify the mobile device and IMSI is used to authenticate the SIM card. 

What are the benefits and disadvantages of MSISDN?

The benefits of MSISDN are numerous. It is a unique identifier that allows mobile network operators to identify and route calls and messages to the correct mobile device. It is also an essential part of mobile number portability, allowing users to keep their phone number when switching between mobile network operators. 

However, there are also some disadvantages to MSISDN. Because it is tied to the mobile device, it cannot be easily transferred to another device. If a user wants to change their mobile device, they will need to get a new MSISDN number. Additionally, MSISDN numbers are subject to SIM card and network limitations, which can impact the user’s ability to make calls and send messages in certain locations.