Skip to main content

Commands used in Dockefile - Part4

  Docker is an opensource tool used for virtualization and deliver software in the form of packages called Containers. It is one of the most important tools used in networking domain.  Dockerfile  is a template for building the image which contains commands needed to package the software. In this post, I am going to explain the commands ADD & COPY used in  Dockerfile .   ADD Command:   ADD command is used to copy files, directories or files from remote URLS to destination path in the image. The source paths can contain wildcards.   If the destination has relative path, it is relative to the Working directory of the image. Note that source path is always relative to the Docker build context.   ADD command will not support authentication. So, if there are any protected files to be added in  Dockerfile  building, use other tools like curl or  wget   Dockerfile  copying Single & Multiple files, directory using ADD inst...
Post a Comment

Introduction to GSM

What is GSM? 
GSM stands for Global System for Mobile Communication. It is nothing but a digital mobile network used by mobiles in Europe and some other countries. GSM uses a variant of Time Division Multiple Access (TDMA). It digitizes and compresses data and send it via the channel in their own time slots. GSM operates at the frequency of 900 or 1800MHz. 

Composition of GSM Network: 
GSM network is composed of three parts namely the Network Switching Subsystem (NSS), Operation and Support Subsystem (OSS), and Base Station Subsystem (BSS). The architecture of the GSM network looks like below: 
GSM architecture 
In GSM, a mobile device is connected to the network via hardware of the BSS. The SIM (Subscriber Identity Module) card is used for the authentication of the mobile user.   

The traffic between NSS and mobile devices is controlled by BSS. The BSS has two components namely Base Transceiver Station (BTS) and Base Station Controller (BSC). BTS has the equipment necessary to communicate with mobile phones. BSC is another entity that communicates with BTS and controls a group of BTS components. 

The NSS component is also known as the core network is used to track the location of callers to enable delivery of the cellular services. Mobile carriers have their own NSS. The NSS has various parts like Mobile Switching Center (MSC) and Home Location Register (HLN). These components perform functions like routing calls, SMS (Short Message Service) and storing caller account information. 

Security of GSM: 
GSM uses authentication in the form of a password. The password is encrypted using stream cipher cryptography algorithms like A5/1, A5/2, and A5/3. These are broken and hence GSM is susceptible to plain text attacks.   

GSM uses General Packet Radio Service (GPRS) to transmit data via web browsing. GPRS uses algorithms like GEA/1, GEA/2 and these algorithms are also broken. 

Comments

Post a Comment

Popular posts from this blog

Vyos - An Open Source Network Operating System

What is  a  Network Operating System?   Networking Operating System (NOS) is an O perating system  that  has the capability to  support workstations, database sharing, application sharing, file ,  and printer access sharing among multiple computers in a network. In general ,  NOS is a specialized operating system used for devices like router, switch or firewall. Features of Networking Operating System:   NOS has the following features: Basic features like protocol support, processor support, hardware detection and multiprocessing support for applications Authentication, access control, authorization ,  and restriction facilities are supported to provide security Provides file service, web service, printing and replication Has Naming and Directory Management services Has  the provision  for user management and remote access & system management Also has internetworking features like routing and ...
Post a Comment
Read more

Notes on IPv4, IPv6 and MAC representations

  In companies related to networking domain, “ Explain IPv4, IPv6 and MAC ” is one of the common questions asked in technical interview. This post provides overview of these concepts. IP: IP is the protocol used in Networking layer. It is responsible for the delivering packets from source to destination based on the identifier known as IP address of the device. There are two popular ways of representing the devices in the network. They are: IPv4  (Internet  Protocol version 4) IPv6 (Internet Protocol version6) IPv4:   This version of IP uses 32-bit addresses to identify the device on the network.  Therefore,  the total number of addresses possible with IPv4 is 2 32 . These  32-bit  addresses are divided into 4 octets (batch of 8 bits) with each octet represented in decimal numbers and octets are separated by dot. In IPv4 the loopback address of a device is  127.0.0.1 . IPv4 supports unicasting, broadcasting and multicasting. To map IPv4 addre...
Post a Comment
Read more

Introduction to Docker and Containers - Overview, Installation, Image and Container creation

Docker is an open source software used to develop and deliver the software in  the  form of packages known as Containers. Software used for hosting containers is known as Docker Engine. Docker is written in the Go programming language. Containers are isolated from each other. Each container has its own libraries, configuration files and there are mechanisms through containers  to  communicate with each other. These containers are created from images which can be modified or customized based on the need. All the containers share the host operating system and hence these are light-weight. An Image from which containers are created is nothing but a package of code, libraries, environment variables and configuration files. For knowing differences between docker containers and virtual machines, click  here . Here we learn how to install  D ocker, build an image, create containers using  the  image, clearing and viewing containers i...
1 comment
Read more