Door phones and paging integration notes

Overview

Door intercoms and overhead paging often hang off analog gateways or multicast systems bridged into Teams. Fragile, site-specific.

Discovery

Identify manufacturer, SIP vs analog FXS/FXO, multicast zone layout, panic/lockdown integrations with access control.

Network

Multicast requires IGMP querier, no Wi‑Fi without mDNS-like hacks—prefer wired speakers. VLAN span mistakes = page storms across campuses.

Security

Isolate doorphone VLAN; PIN protect door relay triggers; log forced entry alerts to SOC if client tier warrants.

Firmware

Treat door stations like IoT: quarterly patch, unique passwords, no port-forward from internet without VPN.

Documentation

Line diagram: which gateway port maps to which door; photo of punch-down; test procedure after power fail.