IT Glossary

What is SD-WAN? Software-Defined Wide Area Network Explained

SD-WAN is a technology that uses software to intelligently manage and route network traffic across multiple connection types (broadband, LTE, MPLS) to connect branch offices to data centres and cloud applications.

Software-Defined WAN (SD-WAN) uses software to control and optimise the routing of network traffic across multiple WAN links. Instead of being locked into a single, expensive MPLS circuit, SD-WAN can aggregate a leased line, broadband, and 4G into a single virtual network. The controller intelligently sends sensitive traffic (VoIP, Zoom) over the best available link in real time, automatically failing over to alternate links if one degrades. For Indian businesses with multiple branches, SD-WAN typically reduces WAN costs by 30–50% while improving cloud application performance.

Why it matters for Indian businesses

Indian businesses with multiple offices — manufacturers with plants and HQ, banks with branch networks, retail chains — historically depended on expensive MPLS circuits to connect them. India's MPLS costs are among the highest in Asia-Pacific. SD-WAN allows these businesses to replace or supplement MPLS with cheaper ILL and broadband, reducing costs dramatically. As Indian businesses accelerate cloud adoption (AWS, Azure, Microsoft 365, Zoho), SD-WAN also improves cloud application performance by breaking out local internet traffic directly instead of backhauling it through headquarters.

Key components

Edge Devices (CPE): Physical or virtual appliances installed at each branch that connect to the SD-WAN controller and manage local traffic.
Centralised Controller: Cloud-based management platform that provides visibility, policies, and configuration for all sites from one dashboard.
Application-Aware Routing: The system identifies application types (Zoom, SAP, web browsing) and routes each over the optimal WAN link automatically.
Transport Agnostic: Works over MPLS, broadband, LTE/5G, or satellite connections.
Zero-Touch Provisioning: New branches can be configured remotely — ship a device, plug in power and internet, and it joins your SD-WAN automatically.

Related terms: MPLS, Internet Leased Line, WAN Optimisation, SASE, VPN, Network Function Virtualisation

Frequently Asked Questions

How much does SD-WAN cost in India?

SD-WAN for a 5-branch Indian business typically costs ₹80,000–₹2,00,000/month including edge devices, management, and underlying connectivity (ILL/broadband). This is typically 30–50% less than equivalent MPLS. Large deployments (20+ sites) get better per-site pricing.

Should Indian businesses replace MPLS with SD-WAN completely?

Most Indian enterprises adopt a hybrid approach — keeping MPLS for latency-sensitive applications (voice, trading) and adding broadband or LTE circuits for cloud applications. Full MPLS replacement works for companies where cloud apps are primary. Businesses with legacy TDM voice or very strict deterministic QoS requirements may need to maintain some MPLS.

What SD-WAN providers are available in India?

Major SD-WAN providers in India include Cisco Viptela, VMware VeloCloud, Versa Networks, Fortinet Secure SD-WAN, and Silver Peak. Indian ISPs like TATA Communications and Airtel also offer managed SD-WAN services.

Spending too much on MPLS? Our SD-WAN experts will analyse your network costs and show you how much you could save.