07 Policy Enforcement

Policy at Wire Speed

How DPUs enforce isolation policies, classify traffic, and make per-packet decisions in nanoseconds—the heart of tenant security.

595M
Decisions/Second
1.7ns
Per Decision
1M+
Policy Rules
100%
Enforcement

Policy Enforcement Pipeline

Every packet traverses a multi-stage pipeline where each stage makes critical decisions. The entire pipeline must complete in under 10 microseconds to maintain wire speed.

📊 Packet Processing Pipeline

📥

Ingress

<1µs
Receive & Buffer
🏷️

Classify

1-2µs
Parse & Match
📋

Policy

2-5µs
Rules Engine
⚖️

QoS

1-2µs
Queue & Shape
📤

Egress

<1µs
Transmit

Total Pipeline Latency: 5-10µs (Hardware) vs 50-500µs (Software)

Hardware vs Software Policy

Software-based policy enforcement cannot scale to AI workloads. Only dedicated hardware can make 595 million decisions per second with deterministic latency.

💻 Software (CPU)

  • Latency 50-500µs
  • Throughput 1-10 Mpps
  • Jitter High
  • CPU Usage 100%
  • Bypass Risk Possible

🔧 Hardware (DPU)

  • Latency 5-10µs
  • Throughput 595 Mpps
  • Jitter Minimal
  • CPU Usage 0%
  • Bypass Risk None

Flow Classification

The DPU extracts multiple fields from each packet and matches against classification rules to determine tenant identity, priority, and applicable policies.

🔍 Packet Field Extraction

VLAN
100
Src MAC
aa:bb:cc:*
Dst MAC
ff:ff:ff:*
Src IP
10.0.1.50
Protocol
RDMA
QP
0x1234

Traffic Priority Classes

DPUs assign traffic to priority queues based on classification results. Higher priority traffic gets guaranteed bandwidth and lower latency.

🎯 Priority Queue Hierarchy

P0

Critical

Control Plane / Heartbeat
100% Guarantee
P1

High

GPU Gradient Sync
Min 60%
P2

Normal

Storage I/O
Min 20%
P3

Background

Checkpoints / Logs
Best Effort

Policy Decision Flow

Each packet goes through a decision tree that determines its fate. Actions include: allow, deny, rate-limit, or redirect—all in hardware.

⚙️ Decision Tree

Valid Tenant?
↙ YES      NO ↘
Within Quota?
🚫
DROP
↙ YES      NO ↘
FORWARD
RATE LIMIT