Multi-ISP Strategies for Enterprises

The Historical Preference for Single-ISP Models

For many years, enterprises relied on single telecom providers to manage their global connectivity needs. Two primary drivers fuelled this choice:

MPLS as the Standard Solution: Enterprises often required MPLS (Multi-Protocol Label Switching) to ensure predictable performance and QoS across global locations. Single ISPs offered global MPLS solutions by subcontracting regional ISPs to handle segments of the path, presenting it as a seamless end-to-end service. However, these arrangements came at a significant markup, inflating costs.

Simplified Billing and Management: Managing global network costs through a single ISP allowed enterprises to consolidate expenses into one entity, simplifying billing and reducing administrative overhead. This was especially attractive to organizations with complex, multi-regional operations.

The Shift Toward Multi-ISP and Internet-First Models

While the single-ISP model worked well under older paradigms, modern business and technology demands have exposed its limitations. Key factors driving the shift to multi-ISP strategies include:

Evolving Technology Needs

• Cloud-Based Collaboration Tools: Applications like Microsoft Teams and Zoom don’t require the strict QoS guarantees of MPLS, as traffic now travels directly over the internet to cloud servers. This eliminates the need for a centralized WAN backbone, reducing reliance on MPLS.
• Direct Internet Breakout: With SD-WAN, traffic for cloud and SaaS applications can exit the network locally, bypassing the traditional MPLS path altogether.

Cost Optimization

• Single-ISP Costs: Global ISPs often subcontract regional providers for MPLS or internet services, adding significant markups. Enterprises pay more for what is, in reality, a multi-ISP solution disguised as single-ISP.
• Multi-ISP Efficiency: Directly engaging local ISPs reduces these unnecessary markups. SD-WAN enables enterprises to replace MPLS with cost-effective broadband and fiber for most traffic, while retaining MPLS only for niche use cases.

Resilience and Performance

• Single Point of Failure: A single ISP introduces a single point of failure. If the ISP has an outage, the entire enterprise network is affected.
• Multi-ISP Redundancy: Engaging multiple ISPs at each location ensures failover capabilities. SD-WAN dynamically routes traffic to healthy links, maintaining uptime.
• Real-World Performance: While MPLS provides predictable paths, internet routes can sometimes offer lower latency and faster speeds, particularly with SD-WAN’s ability to optimize traffic in real time.

Scalability and Flexibility

• Expanding into new regions is slow and costly under a single-ISP model, as businesses depend on the ISP’s ability to provision infrastructure.
• Multi-ISP strategies allow organizations to onboard regional providers almost immediately, leveraging SD-WAN to integrate them seamlessly into the global network.

The Bottom Line: Single-ISP vs. Multi-ISP

Why Single-ISP Worked:

• Guaranteed QoS with MPLS for legacy applications.
• Simplified billing and contract management.

Why Multi-ISP Is Better Today:

• Cost Savings: Enterprises avoid global markups by directly engaging local providers.
• Resilience: Multiple ISPs ensure failover and redundancy, reducing downtime risks.
• Performance: SD-WAN dynamically optimizes traffic paths for modern, cloud-based applications.
• Scalability: Regional ISPs can be provisioned faster and more flexibly than relying on a single global provider.

Real-World Example: Transition from Single-ISP to Multi-ISP

A multinational enterprise relying on a single ISP for global MPLS faced:

• High Costs: Substantial markups due to subcontracted ISPs.
• Limited Performance: MPLS latency in Asia degraded collaboration tools.
• Lack of Redundancy: Outages affected all regional offices.

The Solution:

• Dual-ISP Setup: Each location adopted two regional ISPs for redundancy and performance optimization.
• Direct Internet Access: Cloud-based traffic (e.g., Microsoft Teams, Office 365) using local internet breakout.
• Hybrid Approach: MPLS was retained only for inter-data-center (inter-DC) connectivity across continents, where predictable QoS and reliability were crucial. For inter-DC connections within the same region, wavelength solutions were implemented to provide high-capacity, low-latency links.

Outcome:

Costs dropped by 40%, application performance improved due to optimized ISP routing, and redundancy across ISPs significantly reduced downtime. Critical inter-DC workloads maintained reliability and performance via MPLS (long-distance) and wavelength (regional).

Conclusion

The main drivers for single-ISP solutions—MPLS and simplified billing—are no longer as compelling in today’s cloud-driven world. Multi-ISP strategies offer enterprises the flexibility, cost savings, and resilience they need to adapt to modern demands. While MPLS still has niche use cases for specific private applications, these are becoming exceptions rather than the norm. Paired with SD-WAN, multi-ISP strategies provide a more practical and high-performing solution for global enterprises.