Today you look at the Global/Multi-site Enterprise Security Architecture of an organization and see a myriad of concerns. Increased levels of complexity, difficulties managing multiple third parties, difficulties implementing consistent levels of security, and so on. This makes it imperative for organizations to identify opportunities to simplify, streamline, and generally improve their infrastructure wherever possible.

Managing the level of complexity is becoming increasingly difficult. Security may be partially implemented, which is an ongoing challenging issue.


  • AWS Region – a physical location around the world where we cluster data centers.
  • AWS Availability Zone (AZ) – is one or more discrete data centers with redundant power, networking, and connectivity in an AWS Region.
  • AWS Services – AWS offers a broad set of global cloud-based products, including compute, storage, database, analytics, networking, machine learning and AI, mobile, developer tools, IoT, security, enterprise applications, and more.
  • AWS Transit Gateway (TGW) – A transit gateway is a network transit hub that you can use to interconnect your virtual private clouds (VPCs) and on-premises networks. As your cloud infrastructure expands globally, inter-Region peering connects transit gateways together using the AWS Global Infrastructure.

Global/Multi-Site Enterprise Architecture

Many organizations are using Global/Multi-site with dated technology spread throughout data centers and networks mixed in with some newer technologies. This can include uncounted third parties as well. These sites often include multiple environments (like Dev, QA, Pre-Prod, and Prod) supported by numerous technologies spread across both physical and virtual servers, including databases, web, and application servers, and more.

Modifications can be challenging when integrating legacy with new technologies. Sometimes can require a static approach when completely redesigning existing infrastructure. Understandably, most organizations tend to shy away from exploring anything that seems like a significant upgrade or change. Thankfully there are some solutions available that can substantially improve operations and infrastructure without the typical complexities and implementation challenges.

One such example is outlined below.

TGW diagram

Example AWS Transit Gateway (TGW) Global Diagram

AWS Transit Gateway diagram

AWS Transit Gateway is a cloud-based tool that permits a simplified, secure networking approach for companies requiring a hybrid solution that can scale according to their global/multi-site enterprise business needs. The AWS Transit Gateway integrates with Palo Alto Security Devices, which helps to reduce the organization’s risk footprint.

AWS Transit Gateway architecture is used to consolidate site-to-site VPN connections from your on-premises network to your AWS environment and support connectivity between your team development and workload hosting VPCs and your infrastructure shared services VPC. This information will help you make a more informed decision as you consider the recommended approach of using AWS Transit Gateway.

AWS Transit Gateway connects your Amazon Virtual Private Clouds (VPCs) and on-premises networks through a central hub. This simplifies your network and puts an end to complex peering relationships. It acts as a cloud router – each new connection is only made once.

As you expand globally, inter-region peering connects AWS Transit Gateways together using the AWS global network. Your data is secured automatically and encrypted; it never travels over the public internet, only on the AWS Global Network. Because of its central position, AWS Transit Gateway Network Manager has a unique view over your entire network, even connecting to Software-Defined Wide Area Network (SD-WAN) devices.

General tips

Data transfer charges apply based on the source, destination, and amount of traffic. Here are some general tips for when you start planning your architecture:

  • Avoid routing traffic over the internet when connecting to AWS services from within AWS by using VPC endpoints:
  • VPC gateway endpoints allow communication to Amazon S3 and Amazon DynamoDB without incurring data transfer charges within the same Region.
  • VPC interface endpoints are available for some AWS services. This type of endpoint incurs hourly service charges and data transfer charges.
  • Use Direct Connect instead of the Internet for sending data to on-premises networks.
  • Traffic that crosses an Availability Zone boundary typically incurs a data transfer charge. Use resources from the local Availability Zone whenever possible.
  • Traffic that crosses a regional boundary will typically incur a data transfer charge. Avoid cross-Region data transfer unless your business case requires it.
  • Use the AWS Free Tier. Under certain circumstances, you may be able to test your workload free of charge.
  • Use the AWS Pricing Calculator to help estimate the data transfer costs for your solution.

Use a dashboard to visualize better data transfer charges – this workshop will show how.


A Cybersecurity approach includes how to address a global enterprise architecture.

A collaborative approach permits meetings to review the global enterprise architecture/workflow.

Hold an introductory overview session to gather the preliminary information for each of the sections listed above and in relation to a phased/planned approach for introducing the AWS Transit Gateway. The phases can include compliance with standards such as NIST.

This extensive security approach would cover all the items listed in the prior sections and the required daily business workflows from end to end.

Global/multi-site security certificates, data at rest, data in transit, networks, firewalls/security devices, circuits, and communications. Topics include Strategies, Securing the Edge, Risk-based Cyber assessment, MTDR (Managed Threat Detection and Response), and Endpoint/Network Security

In the future, we will review other Cybersecurity offerings with AWS Services and the reasons why a company would want to invest in AWS Transit Gateway.


AWS provides the ability to deploy across multiple Availability Zones and Regions. This allows organizations to reduce the complexity of their architecture, improve overall performance, and increase dynamic scalability. By streamlining networks and removing unnecessary middlemen, organizations can also improve overall security by reducing risks associated with having multiple vendors while also increasing operational oversight across their infrastructure.

This blog post provided information to help you make an informed decision and explore different architectural patterns to save on data transfer costs. AT&T Cybersecurity offers services to assist you in your joouney. You can review the references listed below to gain additional perspective.

    References & Resources

      • AWS Transit Gateway
      • AWS Overview of Data Transfer Costs for Common Architectures
      • AWS Solutions Library
      • Cisco CSR1000V-Transit VPC with Transit Gateway
      • AWS Pricing Calculator
      • Cost and Usage Analysis Well-Architected Lab
      • Data Transfer Cost Analysis Well-Architected Lab
      • AWS Cost Optimization
    • Clearscale Blog