TCP/IP Protocol Suite

2/1/2024• 3 min read

Comprehensive guide to TCP/IP networking protocols

networkingtcp-ipprotocolsinternet

TCP/IP Protocol Suite

TCP/IP (Transmission Control Protocol/Internet Protocol) is the foundational communication protocol suite of the Internet.

Introduction

TCP/IP is a layered protocol suite that enables communication across different networks. It consists of multiple protocols working together.

TCP/IP Model Layers

1. Application Layer

Provides services to user applications.

Protocols:

  • HTTP/HTTPS
  • FTP
  • SMTP
  • DNS
  • SSH
  • Telnet

2. Transport Layer

Ensures reliable data delivery between hosts.

Protocols:

  • TCP (Transmission Control Protocol)
  • UDP (User Datagram Protocol)

3. Internet Layer

Handles routing and addressing.

Protocols:

  • IP (Internet Protocol)
  • ICMP (Internet Control Message Protocol)
  • ARP (Address Resolution Protocol)

4. Network Access Layer

Handles physical transmission of data.

Technologies:

  • Ethernet
  • Wi-Fi
  • PPP

TCP (Transmission Control Protocol)

Characteristics

  • Connection-oriented: Establishes connection before data transfer
  • Reliable: Guarantees delivery and order
  • Flow Control: Prevents overwhelming receiver
  • Congestion Control: Manages network traffic

TCP Header

| Source Port | Destination Port |
| Sequence Number |
| Acknowledgment Number |
| Flags | Window Size |
| Checksum | Urgent Pointer |

TCP Connection Lifecycle

  1. SYN: Client sends synchronization request
  2. SYN-ACK: Server acknowledges and sends its SYN
  3. ACK: Client acknowledges server's SYN
  4. Data Transfer: Both sides can send data
  5. FIN: Connection termination

TCP Features

  • Three-Way Handshake: Connection establishment
  • Four-Way Handshake: Connection termination
  • Sliding Window: Flow control mechanism
  • Congestion Control: AIMD (Additive Increase Multiplicative Decrease)

UDP (User Datagram Protocol)

Characteristics

  • Connectionless: No connection establishment
  • Unreliable: No delivery guarantee
  • Fast: Low overhead
  • No Flow Control: Sends data as fast as possible

Use Cases

  • DNS queries
  • Video streaming
  • Online gaming
  • VoIP
  • Broadcasting

IP (Internet Protocol)

IPv4

  • 32-bit addresses
  • 4.3 billion possible addresses
  • Dotted decimal notation (192.168.1.1)

IPv6

  • 128-bit addresses
  • Virtually unlimited addresses
  • Hexadecimal notation
  • Built-in security features

IP Addressing

  • Network ID: Identifies network
  • Host ID: Identifies host on network
  • Subnet Mask: Separates network and host portions

IP Routing

Process of forwarding packets from source to destination through intermediate routers.

Common Network Protocols

HTTP/HTTPS

Hypertext Transfer Protocol for web communication.

DNS

Domain Name System translates domain names to IP addresses.

FTP

File Transfer Protocol for file sharing.

SMTP

Simple Mail Transfer Protocol for email transmission.

Network Security

Firewalls

Filter network traffic based on rules.

VPN

Virtual Private Network for secure communication.

SSL/TLS

Encryption protocols for secure data transmission.

Troubleshooting Tools

  • ping: Test connectivity
  • traceroute: Trace packet path
  • netstat: Network statistics
  • wireshark: Packet analyzer
  • nmap: Network scanner

Related Documentation