What is SD-Branch and How Does It Compare to SASE?
Software-defined branch (SD-Branch) is an extension of SD-WAN with appliances deployed at each remote site. While it centralizes management in the cloud, the need for on-site hardware adds cost, complexity, and management overhead.
Secure Access Service Edge (SASE) is a cloud-native alternative to SD-Branch, implementing security and network management capabilities in a network of cloud-based PoPs. Its lack of hardware makes it highly scalable and reduces management overhead, leading many organizations to adopt it as a replacement for SD-Branch.
Understanding SD-Branch
SD-Branch extends the corporate SD-WAN deployment to remote sites via LAN/WLAN management hardware installed on-site. Originally, this was appealing because it centralized LAN/WLAN management, unlike legacy routers. However, this approach also introduces appliance sprawl, additional management overhead, and has limited scalability.
How SD-Branch Works
With SD-Branch, each branch location on the corporate network has its own appliances for SD-WAN, firewall, LAN, and WiFi. Corporate policies are centrally managed, but enforcement is local to individual branches. As a result, each branch office needs to maintain its own hardware, increasing management complexity.
Strengths and Limitations
SD-Branch was popular in the past because it consolidated many key functions in a single appliance and supported LAN/WLAN. Centralized management can also decrease overhead and works well for limited sites.
However, SD-Branch deployments’ reliance on hardware means that they have limited scalability and require periodic hardware refreshes. Additionally, the reliance on discrete appliances can introduce security gaps and means that the IT infrastructure is not optimized for cloud-forward organizations.
What Is SASE?
SASE converges networking and the security capabilities of Security Service Edge (SSE) in a cloud-native architecture. A global network of distributed PoPs implements these capabilities at the network edge without the need for branch hardware, and centralized policy management reduces management overhead.
Main Components of SASE
SASE is defined by converging several network and security functions into one integrated solution. Key components include:
- Software-Defined WAN (SD-WAN): Offers intelligent, optimized traffic routing between SD-WAN PoPs across the corporate WAN.
- Secure Web Gateway (SWG): Monitors and secures web traffic against web-based threats, malicious content, and policy violations.
- Cloud Access Security Broker (CASB): Acts as an intermediary between cloud services and users for policy enforcement, visibility, and threat prevention.
- Firewall as a Service (FWaaS): Delivers next-generation firewall (NGFW) abilities through a cloud-based service.
- Zero Trust Network Access (ZTNA): Enforces zero trust access controls and continuous verification for access to corporate applications and resources.
- Data Loss Prevention (DLP): Identifies and prevents the dissemination of sensitive data outside of an organization’s network.
Cloud-Native Architecture and Scalability
SASE PoPs move traffic routing and security enforcement to the network edge. Users’ traffic is sent to the most convenient PoP, which inspects it and sends it on to its destination.
This design makes SASE much more scalable than SD-Branch, since new cloud-native PoPs can be added instantly, while new SD-Branch sites require appliance installation and configuration. Additionally, the distributed cloud edge offers greater resiliency and lower latency than SD-Branch appliances, which are only deployed at corporate sites.
SD-Branch vs. SASE: Side-by-Side Comparison
SD-Branch is a hardware-centric approach to connecting remote branches, while SASE offers cloud-centric connectivity and security for branches and remote users alike. Many organizations are transitioning from SD-Branch to SASE due to considerations such as scalability, TCO, management overhead, and integrated security capabilities.
Feature Comparison: SD-Branch vs. SASE
How SASE Addresses SD-Branch Limitations
SD-Branch was designed for networks where most users and devices are located on-site at the headquarters or remote site. As a result, it has significant limitations, such as hardware sprawl, limited scalability, and a lack of cloud support.
SASE was created to meet the needs of the modern, cloud-forward business. Its cloud-native PoPs and centralized management eliminate the traditional limitations of SD-WAN.
Eliminating Hardware Dependence
SD-WAN requires all remote sites to deploy appliances to support SD-WAN, firewall, and more. This slows down deployment, increases CapEx, and requires ongoing management.
SASE, on the other hand, is a cloud-native approach, eliminating the need for physical appliances. This enables new PoPs to be deployed instantly and cheaply, allowing branches to be onboarded in minutes rather than weeks.
Unified Networking and Security
Traditionally, SD-Branch focuses on network connectivity and requires standalone firewalls, SWG, CASB, and other security solutions. This contributes to appliance sprawl and introduces visibility and security gaps.
In contrast, SASE integrates SD-WAN, SWG, CASB, FWaaS, and ZTNA into one platform. With a single policy engine and centralized management, SASE improves operational efficiency and decreases management overhead.
Scalability for a Cloud and Hybrid Workforce
SD-Branch is built around physical sites, deploying appliances at each branch location. This makes it ill-suited to supporting remote workforces or cloud-based solutions.
SASE is cloud-native, allowing it to scale or expand its footprint by spinning up additional virtual PoPs. This contributes to workplace flexibility since remote users and branches can be quickly added by connecting to the closest available PoPs.
Cato SASE vs. Traditional SD-Branch
FAQ about SD-Branch
What is SD-Branch?
SD-Branch is an extension of SD-WAN that enables LAN/WLAN management at branch offices. Appliances deployed at remote sites have centralized policy management but require individualized deployment, configuration, and policy enforcement.
Why is SD-Branch less effective today?
SD-Branch was designed before the days of cloud adoption and hybrid work, when deploying appliances at each remote site was enough to serve the organization’s applications and users. Routing traffic through the headquarters network or remote sites introduces network latency, and an appliance-centric approach introduces additional costs and operational overhead.
How does SASE improve on SD-Branch?
SASE provides the functionality of SD-Branch via cloud-native PoPs that are globally distributed and centrally managed. This approach eliminates the overhead associated with appliance management and increases flexibility and scalability as new PoPs can be deployed as needed. Additionally, SASE offers greater security depth than SD-Branch, including inline advanced threat protection, zero trust security enforcement, and integrated advanced threat protection.
Is SD-Branch completely obsolete?
For some organizations, SD-Branch is used as a transitional solution, supporting retail sites and legacy environments. However, industry analysts predict that SASE will eventually replace SD-Branch entirely as companies seek more cost-effective, scalable, and cloud-friendly options.
What’s the difference between SD-WAN, SD-Branch, and SASE?
SD-WAN is a technology focused on WAN optimization. SD-Branch extends SD-WAN into branch-level networking through hardware-based support for LAN/WLAN. SASE is a cloud-native solution that converges SASE with full cloud-delivered security.