Whether you’re an installer, distributor, or end user, we’ve compiled the most common questions about the NX1 and NX250 IP intercoms to help you get the best out of your system. From installation and connectivity to everyday use and support, this FAQ section covers everything you need to know about the NX series’ features, compatibility, performance, and ongoing service.
GSM/4G vs IP – what’s the difference?
The key difference lies in the method of connectivity:
GSM/4G Intercoms
- Connection: Use mobile networks via a SIM card—no wired internet required.
- Installation: Easier and more flexible, especially in remote or hard-to-cable locations.
- Signal Reliance: Dependent on the strength of the mobile network signal.
- Cost: Requires a mobile data plan, but avoids the need for dedicated handsets.
IP Intercoms
- Connection: Use Ethernet or mobile data (4G) to transmit video and audio over the internet.
- Installation: Slightly more involved but allows for robust, stable connectivity—especially when using Ethernet.
- Signal Reliance: More reliable when hardwired; mobile backup (4G) built into NX1 and NX250.
- Cost: Ethernet avoids SIM charges; remote updates and minimal maintenance reduce overhead. For the NX series, there is an additional cost for the SIP subscription, however this is optional.
NX Advantage:
The NX series combines both technologies. It operates as an IP system with Ethernet as the primary connection, while 4G mobile data provides a seamless backup. Video calls use WebRTC; audio calls use SIP or VoLTE, depending on the connection.
How does the NX1 and NX250 work?
When the call button is pressed, the NX systems initiate a video call via the Commtel NEXUS app. They can operate using Ethernet or 4G, depending on the connection method chosen when the unit is installed. The resident receives the call on their smartphone, sees the visitor, and can grant access remotely.
What network infrastructure is required for the NX IP intercoms to function?
The NX IP intercoms connect via Ethernet, and also have 4G capability built in as standard. If using the 4G function, a 4G data SIM with a stable connection is required.
What makes the NX series different?
- Built-in support for both Ethernet and 4G
- Simple setup using the Commtel CONFIG app
- Remote firmware updates and intelligent APN learning
- Powerful, programmable relay functions
- Public holiday-aware time profiles
- Local fallback for access control in case of network failure
How is the NX series different from Vision?
Unlike Vision, which separates audio and video pathways, the NX series offers unified audio-video over IP. Management is fully integrated through the Commtel NEXUS app, enhancing user experience and admin control.
How does the NX series handle network failures?
In a network failure, the NX IP intercoms retain:
- PIN access
- Time profiles and trade entry
- Local relay control
Only calls and video are impacted. Once connectivity is restored, data re-syncs to the cloud automatically.
Does it have power backup?
No battery backup is included, but installers can fit an external PSU if site resilience is required.
Can I use a SIM as a backup?
Yes, this is recommended. If the Ethernet connection fails, the system can instantly switch to 4G data.
What signal strength and upload speeds are required?
- 4G: Minimum -85 dBm for reliable performance
- Upload speed: At least 1.5 Mbps (4G or Ethernet) to support video calling
What is SIP and why do I need a subscription?
SIP is a technology that lets the NX IP intercoms make and receive calls over the internet.
With a SIP subscription, you can:
- Use your phone to open gates/doors. When your phone number is added to the system’s white list, you can call the intercom, and it will recognise your number to activate the relay and open the gate or door.
- Receive phone calls from the intercom. Instead of video calls, the system can make regular phone calls to your mobile or landline phone when someone presses the intercom’s call button.
While SIP is built into the system as standard, you’ll need a separate SIP subscription to use these features. You can manage this subscription through the Commtel NEXUS app.
SIP subscriptions are £5+VAT/month or £60+VAT/year.
Do I need internet to receive a call?
Yes. Either your phone (for the app) or a SIP line (for standard calls) must be internet-connected.
What is the installation and commissioning process?
Installers can download the NX install guide here. Please note you must be logged into your account to do this.
Do I need to open firewall ports when using Ethernet with the NX IP intercoms?
No, unlike some IP intercoms, the NX1 and NX250 do not require any firewall port configuration when connected via Ethernet, making installation simpler and more secure.
Is installer training required?
No, but we’re here if you need us! If you’re familiar with Commtel products, you’ll feel right at home with the NX IP video intercoms.
What relays are included?
The NX1 and NX250 feature three relays:
- 1x 2A relay – Configurable as normally open (N/O) or normally closed (N/C) by default.
- 2x 200mA relays – Normally open (N/O) by default but fully programmable via the app.
Each relay is customisable, allowing you to latch, unlatch, toggle, or pulse based on your specific needs.
How do Installers reprogram the NX IP video intercoms after handover?
Installers will need permission from the admin (homeowner/site manager) to reprogram the device after 30 days from handover. The admin can grant access via the Commtel NEXUS app, or the installer can request it through the Commtel CONFIG app, ensuring end-user privacy and control.
Can the NX1 IP intercom be used for larger installations, such as commercial or multi-residential developments?
The NX1 is designed for single-point entry (e.g. private homes, offices, barriers). However, we do have the NX250 which is suitable for larger multi-user sites. You can find more information about the NX250, here.
Can the NX1 call multiple users?
Not simultaneously, but it supports:
- Call diverting to backup contacts
- Multiple PIN users and dial-to-open (with SIP)
How user-friendly are the NX IP video intercoms for End Users?
Extremely. The Commtel NEXUS app enables:
- Live video call answering
- PIN and access management
- Temporary and scheduled codes
- Installer access control
- Relay control settings
- User management
How are the NX IP intercoms controlled?
Via the Commtel NEXUS app:
- Receive video calls
- Grant access
- Configure PINs and relays
- Manage user permissions
Are there any recurring costs associated with the NX1 and NX250?
- Ethernet only: No ongoing costs
- Using Commtel 4G SIM: £7.50 + VAT/month
- SIP features: £5 + VAT/month or £60 + VAT/year
- Cloud Recording: £3 + VAT/month
What is the warranty period, and what does it cover?
All Commtel products come with a two-year return-to-manufacturer warranty. This covers internal parts and Commtel labour in the event of a manufacturing fault.
Can you purchase spare parts for the NX IP video intercoms?
Yes, spare parts are available for all current Commtel intercoms, including the NX1 and NX250. These are available for our Installers and Distributors to purchase when logged into our website, or by contacting our sales team directly on 01306 710 120 (option 2) or by emailing sales@commtel.io.
How secure is the NX series?
- Data hosted on secure Google and AWS cloud servers with 99.99% uptime
- End-to-end encryption for app-based calls
- Local data storage to maintain access control during outages
How are firmware updates handled?
Updates are managed remotely and installed automatically, ensuring your system is always up to date with the latest features and fixes.
Want to know more about the NX IP video intercoms?
You can explore the features in more detail in our blog post, or click here for a full overview and a list of our Distribution Partners.
Can’t find what you’re looking for?
If your question isn’t answered here, our team is always happy to help! You can reach us on 01306 710 120 (option 1 for technical support or option 2 for sales) or email sales@commtel.io.