Summary

AWS provides multiple options for inter-region connectivity, and the best choice depends on your architecture complexity, data transfer volume, bandwidth requirements, and budget. At a high level, VPC Peering offers the lowest per-GB cost with no hourly fees, making it ideal for simple point-to-point connections—though it lacks transitive routing and becomes operationally complex at scale. Transit Gateway serves as a centralized routing hub that scales linearly across many VPCs and accounts, but introduces a data processing fee that roughly doubles the effective per-GB cost. Direct Connect provides dedicated, guaranteed bandwidth with fixed monthly port costs and is primarily suited for hybrid architectures that require on-premises connectivity or compliance-driven dedicated network paths.

Solution

Pricing Model Comparison

VPC Peering

VPC Peering creates a direct, private connection between two VPCs across regions. Traffic is encrypted automatically and traverses the AWS backbone.

Component	Cost
Setup fee	Free
Hourly/attachment fee	Free
Data transfer (inter-region)	Standard cross-region rates (~$0.02/GB for US-to-US)
Data processing fee	None

Note: VPC Peering has no per-hour charges and no data processing fee. You pay only the standard inter-region data transfer rate per GB, making it the most cost-effective option for simple point-to-point connectivity.

Transit Gateway

Transit Gateway (TGW) is a regional network transit hub. Inter-region peering connects two TGWs across regions, creating a transitive routing fabric.

Component	Cost
VPC attachment (per hour)	~$0.05/hour per attachment
Peering attachment (per hour)	~$0.05/hour per side
Data processing (VPC → TGW)	$0.02/GB
Data processing (peering → TGW)	Free (no charge on receiving TGW)
Inter-region data transfer	Standard cross-region rates (~$0.02/GB for US-to-US)

Note: Transit Gateway adds both hourly attachment fees AND a $0.02/GB data processing charge on top of standard cross-region transfer rates. This effectively doubles the per-GB cost compared to VPC Peering.

Direct Connect

Direct Connect provides a dedicated physical connection from your network to AWS. For inter-region traffic, a Direct Connect Gateway can access multiple regions over a single connection.

Component	Cost
Port hours (1 Gbps dedicated)	$0.30/hour (~$219/month)
Port hours (10 Gbps dedicated)	$2.25/hour (~$1,643/month)
Data transfer out	$0.02/GB (US regions to US DX location)
Data transfer in	Free
Cross-connect fee	Varies by colocation provider

Note: Direct Connect has significant fixed monthly costs regardless of traffic volume. The per-GB DTO rate ($0.02/GB) matches VPC Peering, but port costs make it uneconomical for purely inter-region AWS traffic. It is primarily a hybrid connectivity solution.

AWS Site-to-Site VPN (Over Internet)

AWS Site-to-Site VPN creates encrypted IPsec tunnels over the public internet between your environments. For inter-region connectivity, VPN tunnels can terminate on Transit Gateways or Virtual Private Gateways in each region. This approach leverages existing internet connectivity without requiring dedicated infrastructure, making it the fastest option to deploy.

Component	Cost
VPN connection (per hour)	~$0.05/hour per connection
Data transfer out (internet egress)	~$0.09/GB (first 10 TB/month, tiered pricing)
Data transfer in	Free
TGW attachment (if used)	~$0.05/hour + $0.02/GB processing

Note: VPN over the internet is generally the most expensive option at scale due to internet egress rates (~$0.09/GB versus ~$0.02/GB for VPC Peering). It is best suited for low-bandwidth, backup, or temporary connectivity where cost is secondary to speed of deployment. Performance is also subject to internet variability — latency and throughput are not guaranteed.

AWS Cloud WAN

AWS Cloud WAN is a fully managed global network service that lets you build, manage, and monitor a unified network connecting your offices, data centers, and VPCs across AWS Regions. It provides a central dashboard with policy-based routing and automated network management, abstracting much of the operational complexity of managing Transit Gateways across multiple regions manually.

Cloud WAN uses a Core Network that spans regions and applies network policies to automatically configure routing, segmentation, and connectivity. You define segments (e.g., production, development, shared services) and attachment policies that determine how VPCs, VPNs, and Direct Connect gateways connect to the network.

Component	Cost
Core Network Edge (per hour, per region)	~$0.05/hour per attachment per region
Data processing (per GB)	~$0.02/GB
Peering (inter-region)	Standard cross-region transfer rates + peering data charges
Network policy changes	No additional charge

Note: Cloud WAN pricing is broadly comparable to Transit Gateway (since it uses TGW under the hood), but the value lies in the managed global control plane, automated policy enforcement, and centralized observability. It is best suited for large enterprises managing connectivity across many regions with complex segmentation requirements. For simpler architectures (single inter-region peering), Transit Gateway or VPC Peering remain more cost-effective.

Architectural Constraints & Advantages

VPC Peering — Constraints

The most significant limitation of VPC Peering is that it is not transitive. If VPC A is peered with VPC B, and VPC B is peered with VPC C, traffic from A cannot reach C through B—each pair requires its own dedicated peering connection. This means connectivity scales quadratically: 5 VPCs require 10 connections, while 10 VPCs require 45. Each VPC manages its own route tables independently with no centralized control plane, and peered VPCs cannot have overlapping CIDR blocks. Additionally, VPC Peering does not support edge-to-edge routing, meaning you cannot route traffic through a peered VPC to reach an on-premises network connected via VPN or Direct Connect.

Transit Gateway — Advantages

• Transit Gateway addresses the scaling limitations of VPC Peering by acting as a centralized hub:

• Transitive routing — Any spoke VPC can reach any other spoke through the hub TGW.

• Centralized management — Single route table per TGW, shared across all attachments.

• Linear scaling — Adding a VPC requires one attachment, not N-1 peering connections.

• Multi-connectivity — VPCs, VPN, Direct Connect, and SD-WAN all connect to the same hub.

• Route segmentation — Multiple route tables for network isolation (prod vs. dev).

Direct Connect — Considerations

Direct Connect requires physical infrastructure—colocation space, cross-connects, and partner coordination—which typically takes weeks to months to provision. A single DX connection represents a single point of failure, so high-availability designs require redundant connections across separate locations. On the positive side, a Direct Connect Gateway enables access to multiple AWS regions from a single physical connection. It is important to note that DX traffic is not encrypted by default; you should use MACsec (available on 100 Gbps+ connections) or a VPN overlay to secure data in transit.

When to consider Cloud WAN over Transit Gateway:

• You operate in 5+ AWS Regions with complex routing policies

• You need automated, policy-driven network segmentation at global scale

• Your team wants a single dashboard for global network health and events

• You are managing 50+ VPC attachments across multiple regions

• You want to reduce operational toil of manually managing TGW peering meshes

Performance Characteristics

Metric	VPC Peering	Transit Gateway	Direct Connect	Site-to-Site VPN
Bandwidth	No hard limit (AWS backbone)	Up to 50 Gbps burst	Port speed (1-400 Gbps)	Up to 1.25 Gbps per tunnel
Latency	Lowest — direct path	Slight additional hop	Consistent, low jitter	Variable (internet-dependent)
Encryption	Automatic (inter-region)	Automatic (inter-region)	MACsec or VPN overlay	IPsec (always encrypted)
Bandwidth guarantee	Best effort (shared)	Best effort	Dedicated (guaranteed)	None (internet best effort)

Note: AWS Cloud WAN performance characteristics match Transit Gateway (it uses TGW under the hood) with the added benefit of automated global policy enforcement and centralized observability across all connected regions.

Head-to-Head Comparison

Feature	VPC Peering	Transit Gateway	Direct Connect	VPN	Cloud WAN
Transitive routing	❌ No	✅ Yes	✅ Via DX Gateway	✅ Via TGW	✅ Yes
Overlapping CIDRs	❌ Not supported	✅ With segmentation	❌ Not supported	❌ No	✅ Segmentation
On-premises connectivity	❌ No	✅ VPN + DX	✅ Primary purpose	✅ Yes	✅ Yes
Cross-account support	✅ Yes	✅ Yes (RAM)	✅ Yes	✅ Yes	✅ Yes
Network segmentation	❌ Manual	✅ Multiple route tables	❌ Limited	❌ Limited	✅ Segments
Setup complexity	Low	Medium	High	Low	Medium-High
Effective per-GB cost	~$0.02/GB	~$0.04/GB	~$0.02/GB + fixed	~$0.09/GB+	~$0.04/GB

Decision Framework

Selecting the right connectivity option comes down to understanding your current architecture, growth trajectory, and operational priorities. The following guidance maps common scenarios to the most appropriate solution.

Choose VPC Peering When:

VPC Peering is the right choice when you have a small number of VPCs (typically 2–4) that need direct, cost-optimized inter-region connectivity with predictable point-to-point traffic patterns. It works best when you do not require centralized routing, network inspection, or transitive connectivity between VPCs, and when there are no overlapping CIDR blocks in your environment. If cost per gigabyte is your primary concern and your architecture is relatively simple, VPC Peering will deliver the best economics.

Choose Transit Gateway When:

Transit Gateway becomes the better choice when your environment has 5 or more VPCs, or when you anticipate growth that will make peering connections unmanageable. It is ideal for organizations that need centralized routing governance, transitive any-to-any connectivity, network segmentation across environments (production, development, staging), or a unified hub that combines VPN, Direct Connect, and VPC attachments. Multi-account environments managed through AWS Organizations particularly benefit from Transit Gateway's shared routing model and integration with AWS Network Firewall for centralized traffic inspection.

Choose Direct Connect When:

Direct Connect is the appropriate solution when your primary requirement is connecting on-premises infrastructure to AWS with dedicated, guaranteed bandwidth. It is essential for workloads with compliance requirements mandating a dedicated physical network path, sustained high-volume data transfer between data centers and AWS, or real-time applications that demand consistent low-jitter latency. Through a Direct Connect Gateway, a single physical connection can provide access to multiple AWS regions, making it particularly efficient for organizations with centralized data center operations serving distributed cloud workloads.

Choose Site-to-Site VPN When:

Site-to-Site VPN is the right choice when you need inter-region or hybrid connectivity deployed quickly without waiting for physical infrastructure. It is well-suited for low-bandwidth use cases, temporary or proof-of-concept connectivity, disaster recovery failover paths, or as a backup link alongside Direct Connect. Because it runs over the public internet, it introduces variable latency and throughput limitations (up to 1.25 Gbps per tunnel), making it less appropriate for sustained high-volume workloads. However, its encryption-by-default (IPsec), minimal setup time (minutes), and lack of physical infrastructure requirements make it ideal when speed of deployment outweighs cost efficiency at scale.

Choose AWS Cloud WAN When:

AWS Cloud WAN is designed for large enterprise environments that have outgrown manual Transit Gateway management. Consider Cloud WAN when you operate across multiple AWS Regions with complex routing policies, manage 50 or more VPC attachments, or need automated policy-driven network segmentation at global scale. It provides a single centralized dashboard for network health and events, eliminating the operational burden of manually configuring and maintaining TGW peering meshes across regions. Cloud WAN is particularly valuable for organizations undergoing cloud transformation at scale, where network teams need to enforce consistent connectivity and segmentation policies across business units, environments, and geographies without managing each TGW individually.

Combined Architecture Patterns

In practice, many enterprise environments do not rely on a single connectivity option. Instead, they combine multiple mechanisms to address different traffic patterns and requirements within the same architecture. The example of most common patterns are:

Pattern	Use Case
DX + Transit Gateway	On-prem connects via DX, then TGW routes to multiple VPCs and regions
VPC Peering + Transit Gateway	Peering for high-volume point-to-point; TGW for hub routing to other VPCs
DX + VPC Peering	DX for on-prem connectivity; peering for region-to-region VPC traffic
TGW + Network Firewall	Centralized inspection of all inter-VPC and inter-region traffic
DX + VPN (Backup)	DX as primary path for bandwidth and consistency; VPN as encrypted failover over internet if DX goes down
VPN + Transit Gateway	VPN tunnels terminate on TGW for centralized routing; useful for branch offices or temporary connectivity
Cloud WAN (replaces TGW mesh)	Replaces manual TGW peering mesh with automated, policy-driven global connectivity across 5+ regions
Cloud WAN + DX + VPN	Full enterprise pattern: Cloud WAN manages global routing; DX for primary on-prem paths; VPN for branch/backup

Conclusion

Choosing the right inter-region connectivity option depends on your architecture complexity, transfer volumes, budget, and operational maturity. VPC Peering offers the lowest per-GB cost for simple point-to-point connections; Transit Gateway trades higher per-GB fees for centralized governance and scalability; Direct Connect provides dedicated bandwidth for hybrid/on-premises architectures; Site-to-Site VPN delivers the fastest deployment for backup or temporary links; and Cloud WAN automates policy-driven global routing at enterprise scale. In practice, most deployments combine two or more options — such as Direct Connect with VPN failover, Transit Gateway or Cloud WAN for central routing, and VPC Peering for high-volume direct flows. Start by assessing your traffic patterns and growth trajectory, then match them against the pricing and architectural constraints in this guide.