GSM (Global System for Mobile Communications, originally Groupe SpécialMobile) is a standard developed by the European Telecommunications Standards Institute (ETSI) to describe the protocols for second-generation (2G) digital cellular networks used by mobile phones. The detail information you can learn from Wikipedia.
GSM is a kind of single, you can use device to receive it. For example, your cellphone. This document tell you how to use HackRF and Kali Linux to Sniffing GSM Traffic.
You can go to this link to learn: How to Setup HackRF on Kali Linux
HackRF environment can be setup in multiple Linux. Like: Ubuntu, Debian, Kali. This document show you that how to setup HackRF on kali linux. You can follow this guide to make sure that your HackRF is working on Kali Linux. If you want to buy a HackRF, you can go to this link, which is a offical link to tell you whole things about this device.
LDAP is a good way to manage users and set-up the limited-privilege. LDAP is Lightweight Directory Access Protocol. You can find full information in the wikipedia. People can easily set-up LDAP on the Windows server. However, you have to pay licence fee for windows machine. So, we have another choice — OpenLDAP. For management LDAP we can use an open source software — PhpLDAPAdmin, which based on PHP and web. This means that you can use browser to manage your LDAP.
In this guide, we will install OpenLDAP and PhpLDAPAdmin on the EC2 Ubuntu server.
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