IMSI vs. MSISDN

Attribute	IMSI	MSISDN
Full Form	International Mobile Subscriber Identity	Mobile Station International Subscriber Directory Number
Usage	Used to uniquely identify a mobile subscriber	Used to uniquely identify a mobile phone number
Length	15 digits	Variable length, typically 10 digits
Stored in	Stored in the SIM card	Stored in the HLR (Home Location Register)
Format	Numeric	Numeric

Introduction

IMSI (International Mobile Subscriber Identity) and MSISDN (Mobile Station International Subscriber Directory Number) are two important identifiers used in mobile telecommunications. While both play a crucial role in identifying and authenticating mobile subscribers, they serve different purposes and have distinct attributes. In this article, we will compare the attributes of IMSI and MSISDN to understand their differences and similarities.

IMSI

IMSI is a unique identifier assigned to each mobile subscriber in a GSM or UMTS network. It consists of a 15-digit number that is divided into three parts: Mobile Country Code (MCC), Mobile Network Code (MNC), and Mobile Subscriber Identification Number (MSIN). The MCC and MNC together identify the country and network operator, while the MSIN uniquely identifies the subscriber within the network. IMSI is stored on the SIM card and is used for authentication and identification purposes.

• Consists of a 15-digit number
• Divided into MCC, MNC, and MSIN
• Stored on the SIM card
• Used for authentication and identification

MSISDN

MSISDN is the telephone number assigned to a mobile device in a GSM or UMTS network. It consists of a country code, area code, and subscriber number. The MSISDN uniquely identifies a mobile subscriber in the network and is used for making and receiving calls, as well as sending and receiving SMS messages. MSISDN is stored on the SIM card and is the number that others use to contact the mobile subscriber.

• Consists of country code, area code, and subscriber number
• Used for making and receiving calls
• Stored on the SIM card
• Number used by others to contact the subscriber

Attributes Comparison

While IMSI and MSISDN are both important identifiers in mobile telecommunications, they serve different purposes and have distinct attributes. IMSI is primarily used for network authentication and identification, while MSISDN is used for making and receiving calls. IMSI is stored on the SIM card and is not typically shared with others, while MSISDN is the number that others use to contact the subscriber.

IMSI consists of a 15-digit number that is divided into MCC, MNC, and MSIN, while MSISDN consists of a country code, area code, and subscriber number. IMSI uniquely identifies the subscriber within the network, while MSISDN uniquely identifies the mobile device for communication purposes.

Both IMSI and MSISDN are essential for the proper functioning of mobile networks, but they serve different roles in the communication process. IMSI is used by the network to authenticate and identify the subscriber, while MSISDN is used by other subscribers to contact the mobile device. Understanding the differences between IMSI and MSISDN is crucial for anyone working in the mobile telecommunications industry.

Conclusion

In conclusion, IMSI and MSISDN are two important identifiers in mobile telecommunications with distinct attributes and purposes. IMSI is used for network authentication and identification, while MSISDN is used for making and receiving calls. Both identifiers are stored on the SIM card but serve different roles in the communication process. Understanding the differences between IMSI and MSISDN is essential for anyone working in the mobile telecommunications industry to ensure the proper functioning of mobile networks.