Eighteen sites on one overlay, where a failed link is an event rather than an outage
SD-WAN overlay / multi-site interconnect
Where they started
Each site had a primary MPLS circuit with a consumer broadband backup that was never used because failover required manual intervention at the branch.
The problem, precisely
The backup link existed on paper only, and the datacentre security stack had to apply consistently to branch traffic without backhauling every packet.
What we did
Built an overlay across all links with policy-based routing, then tested link failure in a live branch before rolling the design out anywhere else.
Delivered
- Overlay across all links per site with BFD-driven sub-second failover
- Breakout policy: cloud traffic local, sensitive traffic backhauled through inspection
- Site configuration generated from templates, so a new site is a data entry, not a build
- Link-failure testing in one live branch before any wider rollout
- Per-site monitoring with link quality history, so degradation is visible before failure
Technologies used
Measured result
Every number below was measured and reported to the customer. Where we do not have a measured figure, the entry is a fact rather than a percentage — we would rather be precise than impressive.
- 4 WAN links per site, all in active use
- < 1s measured link failover with no session loss
- 18 sites on one templated configuration
- 1 new site deployable as a data entry
Test link failure in one live site before designing for eighteen. The failure behaviour of your overlay is the product; the link capacity is just an input.