# What is TCP/IP

What is TCP/IP

➡️TCP/IP stands for Transmission Control Protocol/Internet Protocol, which is a set of rules or protocols that govern how data is transmitted over the internet or any network. It is the foundation of the internet and most other computer networks.

Transmission Control Protocol (TCP):

☑️ It ensures that data is delivered accurately and in the correct order.

☑️ It breaks down data into packets, sends them over the network, and then reassembles them at the destination.

☑️ TCP also handles error checking and resends lost or corrupted packets.

Internet Protocol (IP):

☑️ It handles addressing and routing of data packets.

☑️ IP ensures that data packets are sent to the correct destination address (i.e., IP address).

☑️ There are different versions of IP, with IPv4 and IPv6 being the most commonly used.

➡️Layers of TCP/IP:

TCP/IP is structured into four layers, each responsible for different aspects of communication:

Application Layer (Topmost Layer):

☑️This layer provides network services directly to applications, such as web browsers, email clients, or file-sharing programs.

☑️Protocols like HTTP (Hypertext Transfer Protocol), FTP (File Transfer Protocol), and SMTP (Simple Mail Transfer Protocol) operate here.

☑️The application layer formats data so it can be transmitted across the network.

Transport Layer:

☑️The Transmission Control Protocol (TCP) operates here, ensuring reliable data transmission.

☑️It breaks down data into smaller packets, labels them with sequence numbers, and handles the flow control and error checking.

☑️If any packet is lost or corrupted, TCP requests a retransmission.

☑️Another protocol at this layer is User Datagram Protocol (UDP), which is faster but less reliable than TCP (it doesn't guarantee packet delivery).

{% embed url="<https://media.licdn.com/dms/image/v2/D5622AQFx66AiteGy3g/feedshare-shrink_2048_1536/B56ZVmTO4BHEAo-/0/1741178073653?e=1744848000&t=LtItwVZkd_aC4CTY5B1SvlMaQ3wOpZND8KXI8aJGKHM&v=beta>" %}

Internet Layer:

☑️The Internet Protocol (IP) operates here.

☑️This layer is responsible for addressing, routing, and delivering data packets across networks.

☑️Every device on a network is identified by a unique IP address, which is used to route the data to the correct destination.

☑️There are two versions of IP in use today: IPv4 (most common) and IPv6 (newer, designed to solve the address space limitations of IPv4).

Network Access Layer (Link Layer):

☑️This layer handles the physical transmission of data on the network.

☑️It deals with protocols and technologies such as Ethernet, Wi-Fi, or even cellular networks that define how the data packets travel through physical media (wires, radio waves, etc.).

☑️It also deals with hardware addressing like MAC addresses.

hashtag#tcp/ip hashtag#networking hashtag#voip hashtag#revistingfromscratch hashtag#networkengineer


---

# Agent Instructions: Querying This Documentation

If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question.

Perform an HTTP GET request on the current page URL with the `ask` query parameter:

```
GET https://phantanloc.gitbook.io/locpt_wiki/homepage/2.it-cntt/ict/what-is-tcp-ip.md?ask=<question>
```

The question should be specific, self-contained, and written in natural language.
The response will contain a direct answer to the question and relevant excerpts and sources from the documentation.

Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.