TCP/IP Protocol Suite

TCP/IP is the fundamental communication protocol suite used on the Internet and most modern networks.

Internet Protocol (IP)

IP handles the addressing and routing of packets across networks. Each device on a network has a unique IP address.

IPv4

• 32-bit addressing scheme
• Addresses formatted as four octets (e.g., 192.168.1.1)
• Limited to approximately 4.3 billion unique addresses
• Still the most widely used version

IPv6

• 128-bit addressing scheme
• Hexadecimal notation (e.g., 2001:0db8:85a3:0000:0000:8a2e:0370:7334)
• Virtually unlimited address space
• Improved security and efficiency features

Transmission Control Protocol (TCP)

TCP provides reliable, ordered, and error-checked delivery of data between applications.

Key Features

• Connection-oriented: Establishes connection before data transfer
• Reliable delivery: Guarantees packet delivery and order
• Flow control: Manages data transmission rate
• Error checking: Detects and retransmits corrupted packets

Three-Way Handshake

1. SYN: Client sends synchronization request
2. SYN-ACK: Server acknowledges and sends own synchronization
3. ACK: Client acknowledges server’s synchronization

User Datagram Protocol (UDP)

UDP is a simpler, connectionless protocol that trades reliability for speed.

Characteristics

• No connection establishment
• No guaranteed delivery
• No packet ordering
• Lower overhead and latency
• Ideal for real-time applications (video streaming, gaming, VoIP)

Port Numbers

Ports identify specific applications or services:

• Well-known ports (0-1023): Reserved for standard services (HTTP: 80, HTTPS: 443)
• Registered ports (1024-49151): Assigned to specific applications
• Dynamic ports (49152-65535): Temporary ports for client connections