SIM cards store network-unequivocal information used to confirm and perceive endorsers on the association. The most huge of these are the ICCID, IMSI, confirmation key (Ki), neighborhood (LAI) and chairman express emergency number. The SIM moreover stores other carrier express data like the SMSC (Short Message organization center) number, expert association name (SPN), organization dialing numbers (SDN), direction of-charge limits and worth added organization (VAS) applications. (Imply GSM 11.11.[13])
SIM cards can come in various data limits, from 8 KB to something like 256 KB.[7] All can store a restriction of 250 contacts on the SIM, yet while the 32 KB has space for 33 versatile association codes (MNCs) or network identifiers, the 64 KB interpretation has space for 80 MNCs.[14] This is used by network overseers to store data on preferred networks, by and large used when the SIM isn't in its home association yet is meandering. The association executive that gave the SIM card can use this to have a phone interact with a leaned toward association that is more money related for the provider instead of paying the association director that the phone viewed as first. This doesn't suggest that a phone containing this SIM card can connect with a constraint of only 33 or 80 associations, rather it infers that the SIM card sponsor can decide essentially up to that number of leaned toward networks. If a SIM is outside these leaned toward associations, it uses the first or most good that anybody could expect to track down association.
