What is the purpose of the EFADN (abbreviated Dialing Number) file on SIM Card

When I was reading the book Smart Card Applications by Wiley and I came across the "EFADN file".

The EFADN (abbreviated dialing number) file of a SIM can be used here as a typical example. This file can only be read using the READ RECORD command开发者_运维百科 if PIN 1 has previously been correctly verified by the smart card.

What is purpose of this file?

Abbreviated Dialing Numbers refers to short numbers that can be used to reach certain services. The best example is numbers associated with emergency services, e.g. 911.

EF ADN is part of the GSM spec, see ETSI GSM doc GSM 11.11.

EF is smartcard/GSM shorthand for Elementary File, or a regular data file in the filesystem. DF is shorthand for Directory. EF ADN is a telcom specific file located at: MF/DF_TELCOM/EF_ADN

EF ADN is your phonebook. This is the file where you keep your phone numbers and names. But now a days as mobile also has phonebook so people prefer to keep it in phone.

This is the structure of EF_ADN. You need to have the knowledge of CHV pin in order to perform Read or Update operation.

Please refer to GSM 11.11 for better understanding.Im attaching the following links for better understanding.

• http://www.forensicswiki.org/wiki/SIM_Cards
• https://www.google.co.in/url?sa=t&source=web&rct=j&url=http://www.etsi.org/deliver/etsi_gts/11/1111/05.03.00_60/gsmts_1111v050300p.pdf&ved=0ahUKEwj7zaD64J_VAhVDnZQKHSZ2BtcQFggeMAA&usg=AFQjCNEq7Ad39EGij-hYdD6UWOWsPDxbPQ