Tech Matchups: Transit Gateway vs Direct Connect Gateway
Overview
Transit Gateway is a managed service for interconnecting VPCs and on-premises networks in a hub-and-spoke model within a region.
Direct Connect Gateway acts as a global hub for connecting multiple Direct Connect links to VPCs across regions or accounts.
Both enable hybrid networking: Transit Gateway for regional VPC hubs, Direct Connect Gateway for global connectivity.
Section 1 - Connectivity Scope
Transit Gateway connects VPCs and on-premises networks within a region—e.g., linking 10 VPCs and a VPN in us-east-1. Supports dynamic routing via BGP.
Direct Connect Gateway connects Direct Connect links to VPCs globally—e.g., linking a 1 Gbps Direct Connect in Tokyo to a VPC in us-west-2. Uses virtual interfaces (VIFs).
Scenario: Transit Gateway for regional VPC consolidation; Direct Connect Gateway for global hybrid access.
Section 2 - Routing and Scalability
Transit Gateway centralizes routing with a single route table—e.g., propagating 10.0.0.0/16 to 50 VPCs. Scales to 5,000 attachments, handling thousands of routes.
Direct Connect Gateway routes via VIFs, supporting up to 100 VIFs per gateway—e.g., connecting 10 Direct Connects to 10 VPCs globally. Limited by Direct Connect capacity.
Scenario: Transit Gateway manages 100 VPC routes in one region; Direct Connect Gateway links 5 regions’ VPCs. Transit Gateway scales regionally; Direct Connect Gateway spans globally.
Section 3 - Cost and Setup
Transit Gateway charges per attachment-hour ($0.05 in us-east-1) and data processing ($0.02/GB). Example: 10 attachments with 1TB/month costs ~$360 ($340 hourly + $20 data).
Direct Connect Gateway is free, but Direct Connect costs apply—e.g., $0.30/hour for 1 Gbps + $0.02/GB. Example: 1TB/month costs ~$236.40.
Transit Gateway setup takes ~10 minutes; Direct Connect Gateway requires Direct Connect provisioning (weeks).
Scenario: Transit Gateway for quick regional setups; Direct Connect Gateway for dedicated global links.
Section 4 - Use Case Scenarios
Transit Gateway suits regional architectures—e.g., consolidating 20 VPCs and a VPN for a corporate network.
Direct Connect Gateway fits global hybrid clouds—e.g., connecting data centers in 3 continents to AWS VPCs.
Scenario: Transit Gateway for a regional e-commerce hub; Direct Connect Gateway for a global ERP system.
Section 5 - Comparison Table
| Aspect | Transit Gateway | Direct Connect Gateway |
|---|---|---|
| Scope | Regional | Global |
| Scalability | 5,000 Attachments | 100 VIFs |
| Cost | Attachment + Data | Direct Connect Fees |
| Setup | Minutes | Weeks |
| Best For | Regional Hubs | Global Hybrid |
Transit Gateway for regional networks, Direct Connect Gateway for global connectivity. Combine for hybrid scale.
Conclusion
Transit Gateway and Direct Connect Gateway enable hybrid networking with distinct scopes. Transit Gateway simplifies regional VPC and VPN interconnectivity, ideal for consolidated architectures. Direct Connect Gateway connects global Direct Connect links to VPCs, perfect for multi-region hybrid clouds.
Weigh scope (regional vs. global), scalability (attachments vs. VIFs), and setup (quick vs. physical). Use Transit Gateway for regional hubs, Direct Connect Gateway for global links—or combine: Transit Gateway for VPCs, Direct Connect Gateway for on-premises.