# A Performance Perspective on Web Optimized Protocol Stacks: TCP+TLS+HTTP/2 vs. QUIC

## TL;DR

This paper compares the performance of QUIC and TCP+TLS+HTTP/2, highlighting that while tuning TCP improves performance, QUIC still maintains a significant advantage due to its design features like reduced RTT and better handling of lossy networks.

## Contribution

The study provides a fair comparison by tuning TCP parameters, demonstrating that QUIC's design inherently offers performance benefits over optimized TCP stacks.

## Key findings

- Tuning TCP parameters significantly improves TCP performance.
- QUIC outperforms tuned TCP in connection establishment and lossy networks.
- QUIC's reduced RTT and head-of-line blocking avoidance are key to its performance advantage.

## Abstract

Existing performance comparisons of QUIC and TCP compared an optimized QUIC to an unoptimized TCP stack. By neglecting available TCP improvements inherently included in QUIC, comparisons do not shed light on the performance of current web stacks. In this paper, we can show that tuning TCP parameters is not negligible and directly yields significant improvements. Nevertheless, QUIC still outperforms even our tuned variant of TCP. This performance advantage is mostly caused by QUIC's reduced RTT design during connection establishment, and, in case of lossy networks due to its ability to circumvent head-of-line blocking.