What is the difference between imsi and msisdn?
IMSI - International Mobile Subscriber Identity MSISDN - Mobile
Directory Number Both are two different numbers. One is used to
identify a subscriber by operator. Other is used to route the call.
A subscriber becomes customer of an operator by buying the SIM card
of the operator. At this point the subscriber is allocated an IMSI
and an MSISDN. IMSI is used to identify a subscriber by the
operator. But MSISDN is the number which is used for dialing. So
when you call your friend/a mobile, you call the MSISDN number of
the mobile, not the IMSI. For Eg: Consider 2 subscriber's A &
B. And assume the values given below; IMSI (A) : 987123111111111
IMSI (B) : 987124111111111 MSISDN (A) : 9448012121 MSISDN (B) :
9448121212 So when A would like to call B, A dials the MSISDN
number of B, i.e, 9448121212. And same is true for vice-versa. Now
coming to need of IMSI, when a mobile is switched on, it needs to
identify and authenticate the subscriber with the network. Only
then the mobile will be able to use the network services. So to
identify the user in this scenario, the IMSI of the subscriber is
used. In fact the IMSI is burned in the SIM card, which will be
used while authenticating with network. MSISDN will not be stored
in the SIM. 220.227.79.138 10:18, 3 September 2007 (UTC) : A couple
of important things were left out of that description. There are
three identities IMEI, IMSI and MSISDN. The IMEI is the mobile
phone's identity which is burned into the phone. The IMSI is the
identity of the SIM card. And MSISDN is the phone number. You can
change the phone number of the phone without changing its IMSI (the
sim card). You can keep the same phone number (MSISDN), change
phones (the IMEI) and just move the SIM card (IMSI). By separating
the three identities, it makes it easy for subscribers to easily
upgrade phones without having to change phone numbers or accounting
information. Kgrr (talk) 23:57, 2 June 2008 (UTC)