IP intercom and video door phones: what to specify.

Intercom is simple in concept and easy to specify badly.

Analogue vs IP

Analogue systems need dedicated cabling and are limited in features. IP systems use network cabling, support many stations and integrate with phones, apps, access control and CCTV.

SIP

Many IP intercoms speak SIP, the same protocol as IP telephony. That allows calls to desk phones, softphones and mobile apps, and integration with a PBX.

What to specify

• Door stations: weatherproofing, vandal resistance, camera quality, night view and speaker clarity.
• Indoor units: touch monitors, mobile apps or both.
• Call routing: to a flat, then to a mobile, then to security if unanswered.
• Door release: relay outputs, and integration with access control.
• Resilience: power over Ethernet, UPS and behaviour if the network drops.
• Recording: snapshots or video of every call for later review.

Large developments

Plan the network carefully: distribution per tower, PoE capacity and a central server or cloud service. Test the call path end to end before handover.

Make it usable

Residents and staff should answer calls reliably from the app or monitor, with clear audio. A system people avoid is a system that is not working.