Enhanced Networking on AWS EC2

Key Points

Enhanced Networking Overview

Purpose: Provides better networking performance for EC2 instances.
Benefits: Higher bandwidth, higher packets per second (PPS), and lower latency.

Types of Enhanced Networking

Elastic Network Adapter (ENA)
- Performance: Up to 100 gigabits per second.
- Compatibility: Works with newer generation EC2 instances.
- Usage: General enhanced networking for lower latency.
Intel Virtual Function (VF)
- Performance: Up to 10 gigabits per second.
- Status: Considered legacy.
- Usage: Enhanced networking for older generation instances.

Elastic Fabric Adapter (EFA)

Purpose: Dedicated for High Performance Computing (HPC).
Compatibility: Only works on Linux.
Functionality: Improves network performance for tightly coupled internal node communications within the same cluster.
Technology: Leverages the Message Passing Interface (MPI) standard.
Advantage: Bypasses the underlying Linux OS for even lower latency with a reliable transport.

The main differences between Elastic Network Adapter (ENA) and Elastic Fabric Adapter (EFA) in EC2 are:

Feature	ENA	EFA
Traditional IP Networking	Provides traditional IP networking features for VPC networking	Provides all the same traditional IP networking features as ENA, plus additional capabilities
OS-Bypass Support	Not supported	Supports OS-bypass, allowing applications to communicate directly with network interface hardware for lower latency (beneficial for HPC and machine learning workloads)
API and Applications	Works transparently over TCP/UDP without application changes	Uses the Libfabric API for applications to leverage OS-bypass capabilities; supported applications include MPI and NCCL
Communication Scope	Intra-AZ communication (within the same subnet)	Limited to instances within the same subnet
Workload Optimization	Designed for traditional networking applications using TCP/UDP	Optimized for tightly coupled parallel workloads
Instance Types and Programming Models	Available on various instance types	Specific instance types and programming models based on intended use

Exam Tips

Remember that ENA provides enhanced networking for newer generation EC2 instances.
EFA is specifically designed for HPC workloads on Linux and offers even lower latency.