Why TCP optimization matters

TCP (Transmission Control Protocol) ensures data reaches the user reliably, but plain TCP can be slow because of:

• High latency (long distances between client and server)
• Packet loss (retransmissions delay content delivery)
• Inefficient connection setups (handshakes, multiple connections)

TCP optimization reduces these delays so websites, APIs, and streaming services feel faster.

How Cloudflare optimizes TCP

1. Edge Termination
   • TCP connections are terminated at Cloudflare’s edge servers near the user.
   • Traffic from the edge to your origin can use optimized internal routes.
2. TCP Multiplexing
   • Multiple client connections are consolidated into fewer connections to the origin.
   • Reduces load and latency while improving server efficiency.
3. TCP Fast Open (TFO)
   • Allows sending data during the TCP handshake, reducing the time for new connections.
4. Advanced Congestion Control
   • Cloudflare can dynamically adjust packet sending rate based on network conditions to reduce retransmissions and delays.
5. Packet Loss Mitigation
   • Uses forward error correction (FEC) and smart retransmission strategies to recover lost packets faster.
6. HTTP/3 and QUIC
   • While technically not TCP, Cloudflare encourages HTTP/3 over QUIC as an alternative:
     • QUIC is built on UDP but offers TCP-like reliability with faster connection setup.
     • Greatly reduces latency on lossy or high-latency networks.