What is SASE? A Beginner’s Guide to Secure Access Service Edge

SASE (Secure Access Service Edge) combines SD-WAN and cloud-delivered security services to provide more flexible, secure, and efficient connectivity. In this article, Viettel IDC explains what SASE is, how it works, its core architecture, and the key benefits organizations can gain from implementing this modern networking and security model.

What is SASE? How Does the Architecture Work?

SASE stands for Secure Access Service Edge, a cloud-native security architecture that integrates SD-WAN networking with cloud-based security services such as Zero Trust Network Access (ZTNA), Cloud Access Security Broker (CASB), Secure Web Gateway (SWG), and Firewall as a Service (FWaaS).

Traditionally, network traffic is routed through centralized data centers or private networks for inspection and security enforcement. SASE shifts security controls to the cloud, enabling users, devices, and remote systems to securely access applications and resources anytime, anywhere.

Key Characteristics of SASE Architecture

SASE architecture is built around four core principles:

Identity-Based Security

Access permissions are determined based on user identity, device posture, and contextual information rather than network location. This aligns with modern Zero Trust security principles.

Cloud-Native Design

Both networking and security services are delivered from the cloud, making them easier to scale, continuously update, and manage while reducing operational complexity.

Protection Across All Access Edges

Whether users are working from branch offices, remote locations, mobile devices, or cloud applications, they receive the same level of security and policy enforcement.

Global Distribution

SASE providers deploy Points of Presence (PoPs) and security gateways worldwide, ensuring optimized performance and secure connectivity regardless of user location.

Core Components of SASE

SASE combines multiple networking and security technologies into a unified cloud platform. The primary components of Secure Access Service Edge include:

SD-WAN (Software-Defined Wide Area Network)

SD-WAN is a software-defined networking technology that creates virtual connections between multiple locations. It automatically selects the most suitable internet path for different types of traffic, ensuring optimal performance and reliability without relying solely on traditional private WAN circuits.

FWaaS (Firewall as a Service)

FWaaS delivers enterprise-grade firewall capabilities directly from the cloud. It provides centralized policy enforcement, threat protection, traffic inspection, and access control without requiring on-premises firewall appliances.

SWG (Secure Web Gateway)

A Secure Web Gateway protects users when accessing the internet by blocking malicious websites, malware, and unsafe content. It works by analyzing URLs, files, and browsing activities to prevent threats from reaching corporate systems.

ZTNA (Zero Trust Network Access)

ZTNA follows the Zero Trust security model, granting access only after verifying user identity, device status, and contextual factors.

Unlike traditional VPNs that typically grant broad network access after a single authentication event, ZTNA continuously validates every access request throughout the session.

CASB (Cloud Access Security Broker)

CASB serves as a security layer between users and cloud applications. It monitors cloud activity, protects sensitive data, prevents data leakage, and identifies policy violations across SaaS environments.

Unified Management Platform

A SASE platform centralizes all networking and security functions into a single management console. IT teams can deploy policies, monitor activity, and scale infrastructure efficiently without configuring each technology separately.

Benefits of Secure Access Service Edge (SASE)

Beyond understanding what SASE is, many organizations want to know why it has become a leading cybersecurity and networking strategy.

According to Gartner, by 2024, at least 40% of organizations had established a clear SASE adoption strategy, a significant increase from just 1% in 2018. This rapid growth highlights the increasing importance of SASE in modern enterprise environments.

Simplified Infrastructure and Lower IT Costs

One of the most significant advantages of SASE is the consolidation of networking and security functions into a single cloud-delivered service.

This reduces the number of hardware appliances, software tools, and vendors organizations must manage.

A Forrester Total Economic Impact study found that organizations implementing SASE saved approximately $846,000 in infrastructure costs by eliminating redundant security tools, contributing to a 107% return on investment (ROI) over three years.

The study also reported that IT and security teams reduced the time spent managing policies and resolving incidents by approximately 75%.

Faster Deployment and Easier Scalability

With a cloud-native architecture, SASE allows businesses to scale quickly and deploy security services remotely without complex infrastructure upgrades.

For example, when a technology company opens a new office, the IT team can simply configure remote connectivity and apply security policies through the SASE platform. Employees gain secure access to corporate resources from their first day without waiting weeks for traditional security infrastructure deployment.

Optimized for Hybrid and Remote Work

Hybrid work has become the standard operating model for many organizations.

SASE enables employees to securely access corporate applications and resources from any location—including offices, homes, co-working spaces, and public networks—while maintaining productivity and security.

Enhanced User Experience and Network Performance

SASE improves application performance by intelligently routing traffic and applying security inspection closer to the user.

Features such as optimized traffic routing and single-pass encryption help reduce latency and accelerate cloud access while maintaining strong security controls.

As a result, users enjoy a smoother and faster experience when accessing business resources.

Stronger Security Posture

By integrating multiple security services into a unified platform, SASE eliminates security gaps that often arise from managing separate tools.

When all traffic is inspected through a centralized framework, organizations gain better visibility and more consistent policy enforcement.

According to IDC, 61% of organizations reported improved security outcomes after adopting SASE. Forrester research also found that implementing Zero Trust principles within SASE can reduce data breach incidents by approximately 50% while shortening incident investigation and remediation times by around 40%.

Common SASE Use Cases

SASE is particularly well suited for organizations seeking flexible operations, secure connectivity, and optimized application performance.

Common use cases include:

Hybrid and Remote Workforces

Enable secure access for employees regardless of location or device.

Branch Office and Retail Network Connectivity

Maintain secure and consistent connectivity across branch offices, retail locations, and distributed business operations.

Cloud Adoption and Digital Transformation

Simplify the integration of cloud services and SaaS applications into enterprise network environments.

Global Enterprise Connectivity

Optimize performance and security for multinational organizations with geographically dispersed teams.

MPLS-to-SD-WAN Migration

Reduce networking costs and increase flexibility by transitioning from traditional MPLS networks to software-defined WAN connectivity.

FAQs

How Is SASE Different from Traditional Security?

Traditional security architectures rely heavily on on-premises appliances and centralized data centers.

SASE moves networking and security services to the cloud, enabling security inspection closer to users and applications. This approach reduces latency, improves support for remote work, and simplifies management compared to traditional security models.

What Is the Difference Between SSE and SASE?

SASE combines both networking and security services, including SD-WAN and Security Service Edge (SSE).

SSE focuses exclusively on cloud-based security services such as:

- Secure Web Gateway (SWG)

- Cloud Access Security Broker (CASB)

- Zero Trust Network Access (ZTNA)

In simple terms, SSE represents the security component of the broader SASE architecture.

Should Businesses Choose SASE or SD-WAN?

SD-WAN primarily focuses on connecting branch offices, data centers, and cloud environments.

SASE extends SD-WAN by incorporating cloud-native security services, creating a comprehensive solution for protecting users and applications regardless of location.

Organizations pursuing digital transformation initiatives or supporting remote and hybrid work environments will generally benefit more from adopting SASE.

How to Get Started with SASE

Organizations do not need to implement the entire SASE architecture at once. A phased approach often delivers better results while minimizing disruption.

1. Assess Security and Access Requirements

Identify key access points, remote users, devices, security risks, and existing technologies such as VPNs, firewalls, and proxy services.

2. Develop a Migration Roadmap

Plan the adoption of SASE components—including SD-WAN, ZTNA, SWG, and CASB—based on business priorities and operational objectives.

3. Select the Right SASE Platform

Choose a cloud-native solution with global coverage, centralized management capabilities, and seamless integration with existing infrastructure.

4. Start with a Pilot Deployment

Deploy SASE within a branch office or a selected group of remote employees to validate performance, security effectiveness, and compatibility.

5. Scale and Optimize

After a successful pilot, expand deployment across the organization and continuously evaluate performance, security policies, and operational efficiency.

Build an Effective SASE Architecture with the Right Cloud Infrastructure

Successful SASE implementation requires a cloud platform that is secure, scalable, and highly reliable.

Viettel Cloud Server provides enterprise-grade cloud infrastructure that supports modern networking and security architectures. Available with flexible hourly and monthly pricing models, it helps organizations accelerate digital transformation while maintaining cost efficiency and operational agility.