Transport Layer Protocols

This section introduces the core transport layer protocols responsible for end-to-end communication, data delivery reliability, and congestion control in IP networks.

Protocol

Description

Use Case

QUIC (Quick UDP Internet Connections)

UDP-based protocol offering fast, secure, multiplexed transport. Integrated TLS, faster connection setup, and head-of-line blocking elimination.

HTTP/3, real-time apps, mobile network optimization

TCP (Transmission Control Protocol)

Connection-oriented, reliable, ordered data delivery. Handles retransmission, flow and congestion control.

Web traffic (HTTP/HTTPS), file transfer, email

UDP (User Datagram Protocol)

Lightweight, connectionless protocol with no delivery guarantees. Best for real-time and low-latency communication.

DNS, VoIP, video streaming, gaming

RFC: RFC 9000

Main Features:

  • Runs over UDP but provides reliable, secure transport

  • Eliminates head-of-line blocking with multiplexed streams

  • Uses TLS 1.3 for integrated encryption

  • Faster handshake than TCP + TLS

  • Ideal for mobile and high-latency environments

Use Cases:

  • HTTP/3 protocol stack

  • Real-time applications (e.g., chat, streaming)

  • Mobile browsers and CDN acceleration

Alternative Protocols:

  • TCP + TLS – Traditional but slower

  • SCTP – Also supports multiplexing, less widely adopted

Let us learn more about QUIC:

Jump to “QUIC”

RFC: RFC 9293

Main Features:

  • Reliable, ordered data delivery

  • Flow control, congestion avoidance, retransmission

  • Uses three-way handshake for connection setup

  • Segment sequencing and error detection

  • Default for most internet applications

Use Cases:

  • HTTP/HTTPS traffic

  • File Transfer Protocols (FTP, SFTP)

  • Email protocols (SMTP, IMAP, POP3)

Alternative Protocols:

  • QUIC – Faster startup, built-in security

  • UDP – When speed/latency is more important than reliability

Let us learn more about TCP:

Jump to “TCP”

RFC: RFC 768

Main Features:

  • Connectionless and lightweight

  • No guarantees for delivery, ordering, or integrity

  • Minimal overhead and fast transmission

  • Suitable for real-time communication

Use Cases:

  • Voice over IP (VoIP) and video conferencing

  • DNS lookups and DHCP

  • Gaming and multimedia streaming

Alternative Protocols:

  • TCP – Reliable delivery but slower

  • QUIC – Secure, reliable and built over UDP

Let us learn more about UDP:

Jump to “UDP”