Why Redundancy Matters
A single internet circuit, regardless of SLA, represents a single point of failure. Carrier outages, fiber cuts, and equipment failures can take down business operations for hours. Network redundancy uses multiple circuits from different carriers entering the building through different physical paths to ensure connectivity survives any single failure.
Types of Redundancy
Carrier diversity means sourcing circuits from two or more providers (e.g., AT&T + Spectrum). Path diversity ensures those circuits enter the building through different conduits or entrance facilities. Technology diversity mixes fiber, fixed wireless, and cellular backup so that a single technology failure does not cause a complete outage.
SD-WAN and Redundancy
SD-WAN controllers automate failover between primary and backup circuits in milliseconds, without manual intervention. They also enable active-active configurations where both circuits carry traffic simultaneously, with real-time path selection steering sessions to the healthiest link. This eliminates wasted backup bandwidth that sits idle in traditional active-passive designs.
Common Pitfalls
The most common redundancy mistake is purchasing two circuits from different ISPs that share the same last-mile fiber or building entrance. A backhoe strike or conduit failure takes both down simultaneously. Always verify physical path diversity by requesting entrance facility documentation from each carrier.