IP Intercoms: A Complete Guide

What Is an Intercom?

What Every IP Intercom System Does

Despite the variety of technologies available, every IP intercom system performs three core functions:

• Enables visitor identification - through audio or video verification by occupants or security personnel, or through credentials such as RFID, mobile access, face recognition, or fingerprints.
• Communicates - enabling two-way audio, or audio and video, between visitor and occupant
• Controls access - granting or denying entry via a door release, gate controller, or electronic lock

The term intercom is also used to describe internal room-to-room communication systems within a building, connecting floors, offices, or departments. In this guide, we focus specifically on the access-control use case: managing visitor entry at building access points.

How IP Intercom Systems Work

Traditional intercom systems used dedicated analog wiring to carry audio signals between an outdoor door station and an indoor handset. IP intercom systems — also referred to as network intercoms, SIP intercoms, or IP door intercoms — replace that proprietary infrastructure with standard IP network technology: Ethernet, Wi-Fi, or 5G/LTE.

This shift has two significant consequences. First, IP intercoms can be installed, configured, and managed over the same network infrastructure already present in most buildings — no specialist cabling required beyond a standard network connection. Second, they become part of a connected ecosystem, able to communicate with access control platforms, mobile apps, building management software, and cloud services, rather than operating as isolated standalone devices.

Here's how a typical IP intercom call works end to end:

1. Visitor arrives and presses the call button on the outdoor intercom
2. A call is placed over the IP network using SIP (Session Initiation Protocol) to the configured destination — an indoor unit, home intercom, SIP desk phone, or mobile app
3. A two-way audio and video call is established between the visitor and the occupant
4. The occupant verifies the visitor visually via the live camera feed on their indoor station or mobile device, or by voice through two-way communication
5. The door or gate release is triggered remotely - from the indoor station or the mobile app

Wired vs. Wireless Intercom Systems

Both wired and wireless intercom systems can run on IP. The choice between them comes down to infrastructure, installation context, and reliability requirements:

For permanent installations - particularly in commercial or multi-residential buildings - a wired IP connection is generally preferred for its reliability and security. For gate installations or locations where cable routing is impractical, wireless gate intercom solutions running on 5G/LTE offer a strong alternative without sacrificing core IP functionality.

Indoor and Outdoor Units

A complete IP intercom system involves two categories of hardware. The outdoor intercom is mounted at the entry point and houses the camera, microphone, speaker, call button, and credential reader. Outdoor intercom systems must carry appropriate weatherproofing IP ratings and, in high-traffic or public-facing locations, vandal-resistant housing. The indoor station receives the call — this can be a wall-mounted display, a phone intercom handset, a SIP desk phone, or a mobile app on a smartphone or tablet. In multi-tenant buildings, each flat has its own indoor unit or app registration. In commercial installations, calls can be routed to a reception desk or distributed across multiple devices simultaneously.

IP Intercoms and Access Control

A key advantage of IP intercoms is the ability to integrate intercom access control into a unified platform. An IP intercom door station can communicate directly with an access control system - sharing user credentials, logging access events, and triggering automated responses based on configured rules. A smart intercom can automatically route calls to the correct tenant or department, allow a delivery driver through a gate without a resident present, and log every entry attempt in real time with a full audit trail.

Types & Categories

Understanding the main types of intercom systems helps you match the right technology to your building type, use case, and security requirements.

Audio Intercom Systems

The most basic form of visitor communication — a visitor presses a button; the call rings to an indoor speaker; the occupant responds and releases the door. There is no visual verification of the visitor. These systems are still common in older apartment buildings and small offices where simplicity is a priority.

Video Intercom Systems

A camera is added to the door station, giving occupants a live view of the visitor before releasing the door. Video intercoms are now the standard for most new residential and commercial installations - visual verification significantly reduces the risk of tailgating and social engineering at entry points.

Wireless Intercom Systems

Wireless intercoms connect via Wi-Fi or 4G/LTE rather than fixed cabling - well suited to retrofit projects where running new cable is impractical or disruptive.

→ Full guide: Intercom Retrofit & Replacement

Apartment Intercom Systems

Apartment intercom systems serve multi-tenant buildings with one call button per flat or unit. Each resident receives calls on a dedicated indoor unit or mobile app. Advanced systems support tenant self-management portals, visitor access codes, and integration with building management software.

Home Intercom Systems

A home intercom system provides door-to-room or room-to-room communication within a residential property. Modern smart home intercoms integrate with mobile devices and home automation platforms, replacing wired handsets with app-based indoor units.

Buyer's Checklist: Choosing the Right Intercom for Your Use Case

Before selecting an intercom system, work through these key considerations:

• Building type and size — Is it a single-family home, small office, multi-tenant residential site, or large commercial building? Each has different demands for capacity, tenant management, and integration depth.
• Number of access points — How many doors, gates, or entry points need an intercom station? Multi-point systems need a platform that scales without requiring core hardware replacement.
• Wired or wireless? Is new cabling feasible, or does the project require a wireless intercom system to minimize disruption? For retrofits, this decision shapes the entire hardware shortlist.
• Audio only or video? — For any security-critical environment, a video intercom with a high-resolution camera is strongly recommended. Visual verification reduces tailgating and social engineering risks.
• Integration requirements — Does the intercom need to connect to an access control system, VMS, tenant apps , or a building management system? Confirm compatibility before committing to a platform.
• User management — Who adds and removes users? For apartment buildings, look for tenant-facing self-management portals. For commercial sites, integration with LDAP or Active Directory is often essential.
• Remote management — Can building managers view call logs, release doors, and manage access rules without being on site?
• Power supply — Does the existing infrastructure support Power over Ethernet (PoE), or are separate power runs required for each door station?
• Environmental requirements — Outdoor door stations need appropriate IP ratings for weather resistance; high-traffic locations require vandal-resistant housings.
• Scalability — Can the system grow by adding new entry points, users, or integrations without replacing core hardware?
• Advanced features – Do you need to set personalized advanced features (like ringing the intercom without touching the button or sending pictures to email once motion is detected) or is simply making calls from the intercom and opening the door enough for you?
• Credential types – What types of credentials does your intercom need? Is RFID or PIN enough for you, or do you need additional options, such as fingerprint access or mobile credentials?
• Cybersecurity – How crucial is cybersecurity for your project?

Intercom Security: What to Look For

Intercom security is a system-level concern, not just a product feature. A poorly configured intercom can introduce vulnerabilities rather than eliminate them. Key points to evaluate:

• Encrypted communication - HTTPS for the admin interface, TLS/SRTP for the audio and video call stream
• Credential management - Default passwords changed at commissioning; enterprise systems support LDAP/Active Directory integration
• Firmware update policy - Regular updates from the manufacturer patch known vulnerabilities and maintain network security compatibility
• Access event logging - Every call, door release, and failed access attempt should be logged with a timestamp and auditable on demand
• Network segmentation - Placing IP intercom devices on a dedicated VLAN isolates them from general network traffic in higher-security installations
• Vulnerability management – Implemented proven processes and procedures for transparently managing and responding to security vulnerabilities

How 2N Delivers IP Intercom Systems

2N designs IP intercom door stations for a broad range of building types and installation scenarios, from single-family homes to large multi-tenant residential and commercial access points.

Key models include the 2N IP Style, a 10’’ touch display intercom with powerful camera, 2N IP Verso 2.0, a modular door station that adapts to different credential types and installation environments. The 2N IP Force 2.0, built for demanding outdoor and high-traffic locations; or the 2N IP One, a compact option for simpler single-button installations. All 2N IP intercoms are built on open SIP standards, enabling straightforward integration with third-party access control systems, VoIP platforms, and building management infrastructure.

Next Steps

The best IP intercom is one that fits your building today and can grow with your needs tomorrow. By considering your infrastructure, security requirements, and integration needs, you'll be in a much better position to choose a system that delivers long-term value.