Architecting 1.2Tbps Volumetric DDoS Scrubbing (7024)

Technical Overview

Engineering breakdown of Architecting 1.2Tbps Volumetric DDoS Scrubbing (7024). Bare-metal hardware performance requires isolated kernel parameters, DPDK-enabled NICs, and eBPF/XDP early-drop logic to sustain line-rate inspection at 1.2 Tbps. This article details the control-plane/data-plane separation, flow-state synchronization across 7024 scrubbing nodes, and the telemetry pipeline that feeds real-time mitigation decisions.

Data-Plane Architecture

The data plane leverages AF_XDP zero-copy sockets pinned to dedicated CPU cores (via taskset and cset). Each 200 Gbps NIC queue maps to a dedicated XDP program that classifies packets using a compressed prefix trie (CPT) of known attack signatures. Legitimate traffic is forwarded via a lock-free ring buffer to the application layer for deep inspection; malicious traffic is dropped at the driver level, avoiding kernel network stack overhead.

Control-Plane Coordination

A distributed consensus cluster (Raft-based) manages global blocklists, rate-limit thresholds, and scrubbing policy versioning. The 7024 nodes synchronize flow-state every 10 ms using a custom gRPC streaming protocol over a dedicated 100 Gbps management fabric. This ensures sub-second convergence when new attack vectors emerge.

Telemetry & Observability

Per-flow counters (packets, bytes, TCP flags) are exported via Prometheus Pushgateway with 1-second granularity. A Grafana dashboard correlates scrubbing efficiency (clean traffic / total traffic) with CPU utilization, NIC queue drops, and XDP program execution latency (measured via bpftool prog profile).