Software-Defined Wide Area Networks (SD-WAN): A Comparison with Conventional Networks and the Emergence of Secure Access Service Edge (SASE)

Abstract

The advent of Software-Defined Networking (SDN) has revolutionized the landscape of network management and optimization. Within this paradigm, Software-Defined Wide Area Networks (SD-WAN) have emerged as a pivotal technology, offering substantial improvements over conventional networking approaches. This article delves into the essence of SD-WAN, examining its evolution, key players, and comparing its functionalities and benefits with traditional network architectures. Furthermore, the article explores the Secure Access Service Edge (SASE) framework, highlighting its advantages over traditional SD-WAN.

Introduction

The increasing complexity and demands of modern enterprise networks necessitate innovative solutions to ensure efficiency, security, and scalability. Conventional WAN architectures, often reliant on MPLS circuits, have struggled to keep pace with the dynamic requirements of cloud-centric applications and mobile workforces. SD-WAN, leveraging the principles of SDN, offers a transformative approach to WAN management, enabling optimized, secure, and cost-effective connectivity.

Evolution and Key Players in SD-WAN

SD-WAN technology emerged in response to the limitations of traditional WANs, particularly around the rigidity, high costs, and complexity of MPLS-based networks. The foundational idea was to decouple the control plane from the data plane, allowing centralized management and dynamic routing of traffic based on policies and real-time analytics.

Key players in the SD-WAN market include Cisco, Viptela (acquired by Cisco), VMWare (Velocloud), and Meraki. Each of these entities has significantly contributed to the development and proliferation of SD-WAN technologies:

1. Cisco: Known for its comprehensive networking solutions, Cisco's acquisition of Viptela in 2017 bolstered its SD-WAN portfolio. Cisco's SD-WAN solutions focus on delivering robust security, advanced analytics, and seamless cloud integration (Cisco, 2023).
2. Viptela: Before its acquisition by Cisco, Viptela was a pioneer in the SD-WAN space, recognized for its innovative approaches to network virtualization and overlay technologies. Its solutions emphasized simplicity, scalability, and ease of deployment (Viptela, 2016).
3. VMWare (Velocloud): VMWare's acquisition of Velocloud in 2017 positioned it as a strong contender in the SD-WAN market. Velocloud's cloud-delivered SD-WAN architecture is noted for its simplicity, flexibility, and ability to provide optimized application performance over any transport medium (VMWare, 2023). In November 2023, Broadcom completed its $69bn acquisition of VMware, in a move to build out what the company sees as a multi-cloud strategy. VMware has had a number of owners. It was previously owned by Dell, which took over the virtualization company following its $67bn purchase of EMC in 2016.
4. Meraki: Cisco Meraki offers a cloud-managed IT solution that integrates SD-WAN capabilities with its broader networking portfolio. Meraki's SD-WAN is praised for its ease of use, centralized management, and robust security features (Cisco Meraki, 2023).

SD-WAN vs. Conventional Networks

Traditional WAN architectures typically rely on MPLS circuits to connect branch offices to data centers. While MPLS offers reliable performance and QoS, it is expensive and lacks flexibility. In contrast, SD-WAN provides several advantages:

1. Cost Efficiency: SD-WAN reduces reliance on costly MPLS circuits by leveraging cheaper broadband and LTE connections.
2. Flexibility and Scalability: SD-WAN allows for easy addition of new sites and bandwidth without significant infrastructure changes.
3. Enhanced Performance: By using dynamic path selection, SD-WAN can route traffic based on real-time conditions, ensuring optimal performance.
4. Centralized Management: SD-WAN offers centralized control through software, simplifying network management and provisioning.
5. Security: Integrated security features, such as encryption and secure tunneling, are intrinsic to SD-WAN architectures.

Emergence of Secure Access Service Edge (SASE)

Gartner coined the term Secure Access Service Edge (SASE) in 2019, representing a convergence of WAN and network security services into a single, cloud-delivered service model. SASE aims to address the shortcomings of traditional SD-WAN by integrating comprehensive security functions such as SWG, CASB, ZTNA, and FWaaS.

Benefits of SASE Over SD-WAN

1. Unified Security Framework: SASE integrates various security services, providing a holistic approach to secure network access.
2. Cloud-Native Architecture: Designed for the cloud era, SASE ensures seamless and secure connectivity to cloud applications and services.
3. Zero Trust Network Access (ZTNA): SASE implements zero trust principles, ensuring strict verification and minimal implicit trust.
4. Scalability and Agility: As a cloud-delivered model, SASE offers enhanced scalability and agility, adapting to the dynamic needs of modern enterprises.
5. Simplified Management: By converging networking and security functions, SASE reduces complexity and simplifies management.

Conclusion

SD-WAN represents a significant advancement over traditional WAN architectures, offering improved performance, flexibility, and cost efficiency. Key industry players like Cisco, Viptela, VMWare, and Meraki have driven its development and adoption. However, as the networking landscape continues to evolve, SASE emerges as a superior solution, addressing the integrated security and connectivity needs of contemporary enterprises. The convergence of networking and security in a single framework positions SASE as a critical technology for the future of enterprise networking.

References

Cisco. (2023). Cisco SD-WAN: Transforming Your Network Edge. Cisco.

Cisco Meraki. (2023). Meraki SD-WAN. Cisco Meraki.

Viptela. (2016). Viptela: Innovating SD-WAN. Viptela.

VMWare. (2023). VMWare Velocloud: Cloud-Delivered SD-WAN. VMWare.

Gartner. (2019). The Future of Network Security Is in the Cloud. Gartner.