Contra - A Programmable System for Performance Aware Routing

Explore a groundbreaking system for performance-aware routing that adapts to traffic changes at hardware speeds in this 20-minute conference talk from NSDI '20. Dive into Contra, a versatile solution that operates seamlessly across various network topologies and routing policies. Learn how users can write network-wide policies to rank paths based on current performance, and discover the innovative compiler that transforms these policies into switch-local P4 programs. Understand the specialized distance-vector protocol that generates compact probes for dynamic path optimization. Examine Contra's scalability in large networks and its competitive performance in flow completion times compared to topology-specific systems. Gain insights into the Contra language syntax, policy analysis, handling of changing metrics, and evaluation results across different network scenarios.

Intro
Motivation: Performance-aware routing
Contra language syntax
Contra can support many policies
How can we compile the policies to switch programs?
Policy analysis
Defining routing protocols on the PG
Handling changing metrics: Loops
Handling changing metrics: Out-of-order delivery
Handling change metrics: Policy violation by flowers
Evaluation setup
How scalable is the Contra compiler?
How competitive is contra against hand-crafted solutions?
How about arbitrary topologies?
Conclusion