Network Architecture Diagram Builder

Stemma is a free, browser-based tool for drawing network architecture diagrams — also called network diagrams, network topology diagrams, or data-flow diagrams — for security reviews and compliance audits.

What is a network architecture diagram?

A network architecture diagram is a visual map of the systems, services, zones, and connections that make up an environment. It shows how traffic flows between components, where trust boundaries sit, and which segments hold sensitive data. Auditors, security teams, and engineers use it to understand scope, evaluate risk, and prove that controls are in place.

Compliance frameworks that require or rely on a network diagram

A current network architecture diagram is required evidence — or strongly recommended supporting evidence — for most major security and privacy frameworks:

  • SOC 2
    Evidence of system boundaries and data flows for the Security and Confidentiality TSCs.
  • PCI DSS
    Requirement 1.2.4 mandates an up-to-date diagram of all CDE connections and data flows.
  • HIPAA
    Supports the Security Rule risk analysis by mapping ePHI movement across systems.
  • FedRAMP
    Required as part of the System Security Plan (SSP) authorization boundary.
  • NIST SP 800-53
    Supports CA-3, PL-8, and SC-7 boundary protection and architecture controls.
  • NIST CSF
    Maps to ID.AM-3 (data flows) and PR.AC-5 (network integrity).
  • CIS Controls
    Control 12 (Network Infrastructure Management) expects documented network architecture.
  • GDPR
    Used as supporting evidence for Article 30 records of processing and data-transfer mapping.
  • Cyber Essentials Plus
    Required to scope boundary firewalls and internet gateways during assessment.
  • NIS2
    Supports network and information system risk-management measures under Article 21.
  • TISAX
    Required for information-security assessments of automotive supplier networks.
  • SOC 1
    Documents the IT environment supporting financially relevant controls.
  • ISO 27017
    Maps cloud service architecture and tenant isolation boundaries.
  • ISO 27018
    Documents how PII flows through cloud network segments.
  • ISO 22301
    Supports business-continuity impact analysis by showing critical dependencies.
  • HITRUST CSF
    Required network diagram for control 09.m (Network Controls) and scoping.
  • FISMA
    Required for the System Security Plan and authorization boundary definition.
  • GLBA Safeguards Rule
    Supports written information security program scoping for customer data.
  • SOX (IT controls)
    Documents systems in scope for financial reporting IT general controls.
  • CMMC
    Required for AC.L2-3.1.3 and SC.L2-3.13.1 boundary and flow-control evidence.
  • Essential Eight
    Supports network segmentation and macro-level maturity assessments.

What you can do in Stemma

  • Import a network architecture from Markdown and let Stemma lay it out.
  • Model zones, clusters, services, and the connections between them.
  • Apply classification labels (Public, Internal, Confidential, Restricted).
  • Export to PNG for audit packs, runbooks, and security reviews.
  • Runs entirely in your browser — no install, no account required.

Frequently asked questions

What is a network architecture diagram?

A network architecture diagram is a visual map of the systems, services, zones, and connections that make up an environment. It shows how traffic flows between components, where trust boundaries sit, and which segments hold sensitive data.

What is the difference between a network diagram and a network topology diagram?

A network topology diagram focuses on the physical or logical shape of the network (stars, meshes, subnets). A network architecture diagram is broader: it includes services, data flows, security zones, and the relationships auditors care about.

Which compliance frameworks require a network architecture diagram?

PCI DSS, FedRAMP, HITRUST, CMMC, and FISMA explicitly require one. SOC 2, ISO 27001/27017/27018, NIST CSF, NIS2, TISAX, Cyber Essentials Plus, GDPR, GLBA, SOX IT controls, and the Essential Eight rely on it as supporting evidence.

How do I create a network architecture diagram in Stemma?

Click Build Diagram, then add zones, clusters, and services on the canvas — or paste a Markdown description and Stemma will lay it out for you. Export to PNG for audit packs.

Is Stemma free to use?

Yes. You can build, edit, and export network architecture diagrams in your browser for free.

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