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Introduction to IP Video Intercom Systems

Learn how IP video intercom systems work, including outdoor and indoor stations, PoE networking, electric strikes, call routing, installation layout, and troubleshooting.

An IP video intercom is a network-connected door-entry and access-control system. It combines visitor communication, live video, and—when compatible door hardware is installed—remote door release.

These systems are also called video door entry systems, video doorbells, or outdoor station systems. Their main purpose is to let an occupant identify and communicate with a visitor before deciding whether to grant entry.

IP Video Intercoms Compared with Analog Audio Intercoms

A traditional analog voice intercom provides two-way audio between the entrance and an indoor handset or station. An IP video intercom adds a camera and uses a TCP/IP network—the protocol environment used by network devices to exchange data.

Video provides an additional identity check. An occupant can observe the visitor, surroundings, and entry area instead of relying only on the caller's voice. Network connectivity also enables functions such as multiple indoor endpoints, mobile call handling, live viewing outside an active call, recording, and integration with cameras or alarm devices.

Capability	Analog audio intercom	IP video intercom
Visitor communication	Two-way audio	Two-way audio with network-based call handling
Visual verification	Usually unavailable	Live video from the entrance camera
Network connectivity	Usually dedicated analog wiring	Ethernet or supported Wi-Fi connection to a LAN
Multiple indoor endpoints	Depends on dedicated system wiring	Can support configured one-to-one or one-to-many routing
Mobile-call support	Usually unavailable	May forward calls to a supported mobile application
Video recording	Unavailable	May be available through an indoor station or SD card
Remote live view	Usually unavailable	May be available on demand
Access-control integration	Basic release functions may be available	Can integrate with electric locks, cameras, and alarm I/O

Core Benefits

Live video viewing: See the visitor through the entrance camera.
Two-way audio: Speak with the visitor before opening the door.
Remote door release: Activate an electric locking device from an authorized indoor station or supported remote endpoint.
Network reuse: Use a suitable existing Ethernet and IP network.
Simultaneous ringing: Make several indoor stations receive the same call.
Mobile answering: Forward or answer calls through a supported mobile application.
On-demand viewing: Open the entrance camera's live feed even when no call is active.
Local recording: Store compatible call recordings on an indoor station's SD card.
System integration: Add supported surveillance cameras and alarm-related input/output devices.

Main Components

Outdoor Station

The outdoor station is the entrance-mounted unit. It normally contains the camera, microphone, speaker, and visitor calling interface. A small property may use physical call buttons for individual rooms or residents. A larger building may use a numeric keypad or directory interface for multiple users.

The outdoor station connects to the network and receives power through either a compatible PoE connection or a separate low-voltage supply. It may also connect to the door-release circuit. Select and mount outdoor hardware for the entrance environment, considering exposure, mounting position, weather protection, visibility, and tamper resistance.

Indoor Station

The indoor station is the occupant-side endpoint. It receives calls, displays the visitor's live video, provides two-way communication, and offers an unlock control when a compatible release circuit is connected.

Depending on the model, an indoor station may connect through a wired LAN or supported Wi-Fi. It may use 12 V DC power, Power over Ethernet, or both as supported by the manufacturer. Optional functions include viewing IP cameras, recording calls, saving recordings to an SD card, and connecting external devices through alarm I/O terminals.

Electric Strike and Door Release

An electric strike is a door-frame locking component that releases the door latch when electrically activated. An authorized user presses unlock on an indoor station or supported remote endpoint. The station or its control output then activates the release circuit for the configured duration.

The strike, power supply, relay or control output, and door hardware must be compatible. Verify voltage, current, wiring, release behavior, and fail-safe or fail-secure requirements before installation. Lock power requirements must be checked separately from the PoE requirements of the intercom devices.

PoE Switch

PoE means Power over Ethernet. A compatible PoE switch can carry network data and electrical power over the same Ethernet cable to compatible outdoor and indoor stations. This can reduce the need for separate 12 V DC adapters at those endpoints.

PoE does not automatically power every part of the installation. The electric strike may require a separate supply or a separately rated control circuit. Confirm the switch's PoE standard, port capabilities, total power budget, cable condition, and endpoint demand.

Mobile Application

A supported mobile application can receive a forwarded visitor call, show the entrance camera, provide two-way audio, and possibly provide remote unlock. Remote release should be enabled only when the system is properly secured and users understand when they are authorizing entry.

Component	Location	Primary function	Connectivity and power	Optional features
Outdoor station	Entrance	Captures video, communicates with visitors, and starts calls	Ethernet or supported IP connection; PoE or separate low-voltage power	Keypad, directory, extra inputs, lock-control output
Indoor station	Inside the home, office, or room	Receives calls, displays video, provides audio and unlock control	LAN or supported Wi-Fi; 12 V DC or PoE, depending on model	IP-camera viewing, recording, SD card, alarm I/O
Electric strike	Door frame	Releases the latch when activated	Separate compatible lock power and control wiring	Configured release duration and access behavior
PoE switch	Network cabinet or equipment area	Connects IP devices and may power them	Ethernet ports with sufficient PoE capacity	Centralized power and network monitoring
Mobile application	User's mobile device	Receives forwarded calls and may provide remote viewing or release	Requires supported service and network connectivity	Remote visitor handling

Basic Operating Sequence

The visitor presses a call button or selects a directory entry at the entrance.
The outdoor station initiates a call to one configured indoor station or a group of indoor stations.
The indoor station alerts the occupant and presents the outdoor station's live video feed, meaning the real-time camera stream.
The occupant assesses the visitor and may speak with them using two-way audio.
If entry is appropriate, the occupant selects unlock.
The unlock command activates the electric strike for its configured release period, allowing the latch to move.

Multi-Station Call Routing

A one-to-one arrangement sends an entrance call to one indoor station. A one-to-many arrangement sends the call to several stations. In simultaneous ringing, all members of the configured station group alert at the same time.

For example, a building can have one entrance station and three indoor stations: one in an office, one in a reception area, and one in a residence. When the entrance button is pressed, all three stations can ring. The first authorized occupant to answer can view the visitor, communicate, and release the door.

Call destinations must be configured. A physical button, keypad entry, or directory entry must map to the intended indoor station or station group. A station that is powered but not registered, online, or included in the group will not reliably receive the call.

Basic Network and Power Architecture

IP intercom devices communicate over a LAN using TCP/IP. A typical installation places the outdoor station and indoor stations on the same intended local network, either directly through Ethernet or through a suitable network infrastructure.

Outdoor station ── Ethernet/PoE ──┐
Indoor station 1 ─ Ethernet/PoE ──┤
Indoor station 2 ─ Ethernet/PoE ──┤── PoE switch ── LAN
Indoor station 3 ─ Ethernet/PoE ──┘

Outdoor station ── compatible lock-control circuit ── electric strike

With PoE, the switch supplies both data connectivity and power to compatible endpoints. With separate power, each device may use an appropriate 12 V DC supply while Ethernet carries network data. Do not assume that the intercom's device power output is suitable for the electric strike. Verify the strike's power source and the release circuit independently.

Device	Quantity	Network connection	Power method	Role in the call and access sequence
Outdoor station	1	Ethernet to the PoE switch or LAN	PoE or separate low-voltage supply	Starts the visitor call, supplies video and audio, and sends the unlock control
Indoor stations	3	Ethernet or supported Wi-Fi	PoE or 12 V DC, according to the model	Ring simultaneously, show video, provide audio, and allow an authorized user to unlock
PoE switch	1 or more	Uplink to the LAN and ports for endpoints	AC input with a rated PoE budget	Provides network connectivity and may power the intercom endpoints
Electric strike	1 per controlled door	Not normally an IP endpoint	Compatible separate lock supply or rated release circuit	Releases the door latch after an authorized unlock command

Basic Configuration Checklist

Assign and Verify Network Connectivity

Connect each endpoint to the intended LAN through Ethernet or, where supported, Wi-Fi.
Confirm that the outdoor and indoor stations can reach one another on the intended network.
Check addressing, link status, and device registration according to the equipment documentation.

Configure Call Destinations

Map each outdoor call button or directory entry to the intended indoor station or station group.
Enable simultaneous ringing when multiple occupants should receive the same call.
Test both answering and missed-call behavior where supported.

Configure Access Release

Connect the outdoor station's rated relay or control output to the compatible door-release circuit.
Set the unlock behavior and release duration to match the lock hardware.
Test the door mechanically and electrically, including normal operation after the release period ends.

Configure PoE and Optional Features

Use a PoE-capable switch with compatible endpoints.
Calculate whether the switch has enough available power for every connected intercom device.
Enable mobile forwarding, SD-card recording, supported camera views, or alarm I/O only when those features are required and properly configured.

Practical Installation Examples

Single-Entrance, Multi-Room Installation

Install one outdoor station at the main entrance and three indoor stations in different rooms. Configure the entrance call button to ring all three stations simultaneously. Connect the outdoor station's compatible control output to the electric strike. Any authorized indoor-station user can view the visitor, talk with them, and admit them.

PoE-Based Deployment

Connect compatible outdoor and indoor stations to a PoE switch. Ethernet runs carry both data and endpoint power, reducing the need for local 12 V DC adapters. Confirm the switch's total power budget and verify the electric strike's separate power and control requirements.

Remote Visitor Handling

Forward a visitor call to a supported mobile application. The user can view the entrance camera and speak with the visitor remotely. Remote unlocking should be intentionally enabled, protected with appropriate account controls, and used only when the user has made a deliberate access decision.

Troubleshooting

Indoor Station Does Not Ring

Confirm that the outdoor station has network connectivity and power.
Verify the call-button destination and station-group configuration.
Confirm that the target indoor station is online and connected to the correct LAN.

Video Is Unavailable or Unreliable

Check network connectivity between the outdoor and indoor endpoints.
Verify that the outdoor station is receiving adequate power.
Confirm that the indoor station and network connection support the required video function.

Door Does Not Unlock

Verify electric-strike wiring and compatibility with the control relay.
Check that the electric strike has its required power source.
Review unlock-output settings and release duration.

PoE Devices Fail to Start or Restart

Confirm that the switch provides compatible PoE.
Compare total endpoint demand with the switch's available PoE power budget.
Inspect Ethernet cables, connectors, and port status.

Only One Indoor Station Receives the Call

Review simultaneous-ring group membership.
Verify that every intended station is registered, online, and assigned to the same call destination.

Key Terms

IP video intercom: A network-based system combining door communication, video verification, and access release.
Video door entry system: Another name for a video intercom used to manage visitors at a building entrance.
Video doorbell: A door-entry device with a camera and calling function, often connected to an indoor monitor or mobile application.
Outdoor station: The entrance-side unit containing the camera, call interface, and often the lock-release output.
Indoor station: The occupant-side monitor or touch panel used to receive calls, view video, talk, and unlock the door.
Electric strike: An electrically controlled strike plate that releases a door latch when activated.
LAN: A local area network connecting devices within a home, office, or building.
Wi-Fi: Wireless LAN connectivity supported by some indoor stations.
Alarm I/O: Input and output terminals for external alarm sensors or signaling and control devices.
SD card: Removable storage media used by compatible stations for local call recordings.
Live video feed: The real-time camera stream from the entrance unit.

For a concise review of the subject, see the IP video intercom introduction.