How ADT Protects Life-Critical Systems with Microsegmentation When Every Second Matters
For 150 years, ADT has built trust by being there in the moments that matter. Today it protects more than 6.4 million homes and small businesses across North America. Its life-safety environment ingests millions of signals every year: fire alarms, carbon monoxide warnings, burglar alarms, low-battery alerts. Each one has to reach the right destination — an agent, an application, a fire department, a police department — in seconds.
“Any interruption could mean an alarm never reaches an agent or emergency responders,” says Joshua Mumme, IT engineer of Life Safety at ADT. “In some scenarios, that can be the difference between life and death.”
That’s the bar security has to clear at ADT. Keep the signal moving, every time.
The problem with perimeter defense
ADT, like most enterprises, had spent years hardening the perimeter. But attackers don’t stop at the firewall. Once inside, they move laterally, quietly hopping between systems and escalating privileges. Perimeter defenses see the front door. They don’t see the hallways inside.
Every enterprise faces this risk. But at ADT, the consequences are immediate and visible — an alarm that doesn’t reach a responder, a signal that drops at the wrong moment.
“We needed protection directly on our servers, not just perimeter firewalls,” Mumme says. “Microsegmentation gave us granular visibility and control beyond what subnet firewalls allow.”
The team had a second non-negotiable constraint: any new control had to leave performance untouched. In a life-safety environment, latency is risk. A security tool that slowed signal traffic would create the exact failure it was supposed to prevent. In other words, performance is part of safety.
Visibility first, then control
ADT moved to a Zero Trust model and looked for a way to segment workloads without having to rearchitect the network. Illumio Segmentation gave the team that path. Rather than routing traffic through chokepoints or rebuilding architecture, ADT could enforce segmentation directly on each host. Protection now lives inside the environment, not just at the edge.
Before any rule got written, the team got something it didn’t have before: a clear picture of how its systems actually talked to each other.
“Illumio has given us much greater insight into our environment,” Mumme says. “We now see activity that was previously invisible, allowing us to better understand what is normal and what requires investigation.”
That clarity made policy possible. The team could lock down what didn’t need to flow without breaking what did.
Containment without compromise
Today, segmentation policies limit how ADT workloads connect. Critical systems stay isolated. If an attacker lands somewhere they shouldn’t, the attacker can’t move. Operations continue. Signals reach agents. Responders get dispatched. The mission keeps running.
“Protecting internal systems isn’t just about stopping attackers,” Mumme says. “It’s about ensuring critical services keep running.”
