Computer Networks for DevOps part-4

Today we are learn some indepth concept of Computer Networks

TCP/IP Model

The TCP/IP model(Transmission Control Protocol/Internet Protocol) is a concise version of the OSI model.

It contains five layers, unlike seven layers in the OSI model 5 layers of TCP/IP Model

1. Application Layer

2. Transport Layer

3. Network Layer

4. Data Link Lyer

5. Physical Layer

1. Application Layer Purpose: User interaction, Example: Whatsapp, Browsers, Where: Devices, Protocols, Client and Server Architecture.

Client-server Architecture

TCP/IP uses the client-server model of communication. This model has two parts. Client part and the server part. These parts will run different processes. They communicate with each other.

A client is a computer hardware device or software that accesses a service made available by a server.

A server is a physical computer dedicated to run services to serve the needs of other computers. Depending on the service that is running, it could be a file server, database server, or a web server.

Collection of servers present in a big company called Data center.

What is Ping?

A ping is a signal sent to the host that requests a response. It serves two primary purposes:

1. to check if the host is available and

2. to measure how long the response takes.

What is ping time?

The time it takes for a small data set to be transmitted from your device to a server on the Internet and back to your device again is called ping time. The ping time is measured in milliseconds (ms).

There is another way through which applications are connected from end system.

Peer to Peer Architecture(P2P)

Hybrid Network Architecture

Hybrid networks are the networks that are based on both peer-to-peer & client-server relationship. Hybrid networks provide all of the centralized services of servers, but they also allow users to share and manage their own resources within the workgroup.

Protocols:

? Web Protocols:

? TCP/IP(Transmission Control Protocol/Internet Protocol) TCP/IP is set of standardized rules that allow computers to communicate on a network such as the internet.

■ HTTP(Hypertext Transfer Protocol)

■ DHCP(Dynamic Host Configuration Protocol)

■ FTP(File Transfer Protocol)

■ SMTP(Simple Mail Transfer Protocol)

■ POP3 & IMAP(Post Office Protocol 3 & Internet Message Access Protocol)

■ SSH(Secure Shell)

■ VNC(Virtual Network Computer)

? Telnet(TErminaL NETwork) Telnet(TN) is a networking protocol and software program used to access remote computers and terminals over the Internet. It manages the account/device remotely. It is working on port 23.

? UDP(User Datagram Protocol) UDP is a connectionless or stateless protocol. It does not maintain the state of data. That’s why data may be lost in this protocol.

Process: Processes are basically the programs which are dispatched from the ready state and are scheduled in the CPU for execution.

Thread: Thread is the segment of a process means a process can have multiple threads and these multiple threads are contained within a process.

Socket

A socket is a two way communication between softwares running on the network. Its an interface b/w a process and the internet. A socket is identified by an IP address concatenated with a port number like,

Ports:

Ports are used for identifying the applications.

Ephemeral Ports:

Ephemeral ports are used for identifying the different instances/processes of an application. Like one browser application contains many tabs. For each tab separate ephemeral port will be used.

This is all about my todays learning : )