How IP intercom works
An IP intercom endpoint is a network device with a speaker, a microphone and a call button (or a hook-off handset). When activated, it establishes a two-way audio session — usually SIP, the same protocol used by VoIP phone systems — to a target: a desk console, a phone handset, a software client, or a group of them. Because it rides the network, an intercom zone can include any mix of endpoints and can be reconfigured without re-cabling.
The underlying architecture is covered in the IP paging and network PA guide. Endpoints are typically PoE-powered, so the same network readiness considerations apply.
Where intercom earns its place in schools
- Classroom call points. A teacher can summon help or the office without a phone call, and the office can respond hands-free.
- Gate and visitor entry. Intercom at the main gate or reception door, often combined with access control for after-hours entry.
- Staff-only zones. Boiler rooms, halls and workshops with a way to reach the office that does not rely on mobile coverage.
- Checking in during lockdown. Selected endpoints allow rooms to report status to the office — subject to your emergency plan's design.
Emergency design considerations generally are covered in the emergency and lockdown communication guide.
SIP, Teams and VoIP integration
Because most IP intercom speaks SIP, it can integrate with a school or business phone system: a gate call can ring a reception handset, a classroom call can appear on a Teams or VoIP client, and missed intercom calls can follow voicemail paths. When specifying, state clearly which phone environment the intercom must integrate with and who supports that integration — the paging installer, the phone system vendor, or both.
Two-way vs one-way: specifying the mix
Most deployments do not need intercom at every speaker location. A common pattern is one-way speakers everywhere plus two-way endpoints at gates, reception, and selected classrooms or specialist rooms. Intercom endpoints cost more than plain speakers and add call-handling complexity, so the specification should list exactly where two-way is required and why. The specification checklist includes an intercom section for this reason.
Cost impact
Intercom uplift depends on endpoint count and integration work. The ballpark calculator lets you model feature scope against indicative NZ installed cost ranges, and the funding checker indicates whether an intercom component might fit a school property funding route.
Related resources
Continue planning your project
Last reviewed 12 September 2026. General information only — integration feasibility always depends on your specific phone system and network.