Comparison Ezviz DP2 vs Dahua DHI-VTH2421F-P

— Internal Panel (Intercom). A device installed inside the premises for communication with visitors through the intercom system. Designed to ensure security, allowing communication with guests and controlling access to the building or apartment without the need to open the door.

— Call Panel. An outdoor device of the intercom system installed at the entrance to the building or apartment. The call panel is intended for visitors to call the hosts or owners of the premises and, if equipped with a camera, provide an exterior image, enhancing the level of security and access control.

— Kit (Panel + Intercom). Having both devices in the kit provides a complete communication and access control system right out of the box. This solution can be advantageous at the initial installation stage because the devices are maximally compatible with each other. However, when upgrading or due to personal preferences in certain functions, it may be easier to choose a call panel separately from the intercom.

Ways to connect devices.

— Wired. Connecting intercom system components through cables ensures stable and reliable signal transmission. In such a connection, a regular wire is used to connect the outdoor call panel with the indoor panel located inside the building. Wired connections provide high-quality sound and image, minimizing interference, and are ideal for stable system operation over long distances. This also enhances security, as wired connections are less susceptible to external influences compared to wireless solutions.

— LAN (RJ-45). Connection via RJ-45 port using an Ethernet-type network cable ("twisted pair"). This option is convenient as devices can be connected to a local computer network, providing several advantages. First, access can be configured on any computer or gadget within the network. Second, many such models can operate without intercoms and other specialized equipment — through an application on a computer/gadget. Third, laying the network cable from the panel to the router/switch is often easier than organizing an analog connection. Fourth, the number of panels and other specialized equipment within the "local network" can be almost unlimited — for example, all the call panels of an apartment building or a large office center can be connected into one network. Additionally, access to the call panel can even be set up via the Internet if desired, providing...

— Wi-Fi. Connection via the wireless Wi-Fi standard. Thi...s option provides nearly all the capabilities of the aforementioned LAN (RJ-45), but has certain differences. The most noticeable is the lack of cables, significantly simplifying installation and connection. Even relatively modest Wi-Fi devices are powerful enough to operate confidently over distances of a couple dozen meters or through 1-2 medium-thickness walls. The most functional and thus the most popular type of analog wired connection. Suitable even for high-end video panels, though it actually appears in all categories of devices — from budget to top-tier.

— RJ-45. Connection via RJ-45 port using an Ethernet-type network cable ("twisted pair"). This option is convenient as the call panel can be connected to a local computer network, providing several advantages. First, access to the panel can be configured on any computer or gadget within the network. Second, many similar models can operate without intercoms and other special equipment — through an application on a computer/gadget. Third, laying the network cable from the panel to the router/switch is often easier than organizing an analog connection (e.g., using 4 wires — see above). Fourth, the number of panels and other special equipment within the "local network" can be almost unlimited — for example, all call panels of an apartment building or large office center can be connected into one network. Furthermore, access to the call panel can even be configured via the Internet, allowing you to communicate with visitors and manage access to the premises even when you're not present.

— Wi-Fi. Connection via the wireless Wi-Fi standard. This option provides nearly all the capabilities of the above-mentioned RJ-45 but with certain differences. The most noticeable is the absence of wires, which significantly simplifies installation and connection. Moreover, even relatively modest Wi-Fi devices are powerful enough to operate confidently over distances of a couple dozen meters or through 1-2 medium-thickness walls. The second nuance is the possibility of direct connection with smartphones, tablets, etc., without using computer networks; this possibility should be confirmed separately, but it is in this format, for example, that video calls operate (see "Type").

— RJ-45 / Wi-Fi. Supports both of the above-described connection methods. Such panels are maximally versatile; however, in practice, the ability to freely choose between LAN and Wi-Fi is rarely required, yet it significantly affects the cost. Therefore, this option has not gained much popularity.

Support for the SIP protocol enables the integration of devices into VoIP (Voice over IP) systems, allowing the use of internet connections for transmitting voice and video calls. SIP (Session Initiation Protocol) is a standard protocol for establishing, managing, and terminating communication sessions over the internet. In intercoms and door panels, SIP support enables video calls and communication with visitors through smartphones, tablets, or other SIP-compatible devices without the need for traditional phone lines. This also opens up opportunities for integrating the intercom system with other smart devices and security systems within a wider network, enhancing the device's flexibility and functionality.

Diagonal size of the intercom's own display.

In modern intercoms, there are displays ranging in size from 2 "to 10" — smaller screens are non-functional, larger ones are unreasonably bulky and expensive. At the same time, you can normally view the image on almost any display from this range — if you lean close enough to it.

With all this in mind, it makes sense to specifically look for a large screen (10 ") if you need to see it normally from a long distance (a metre or more), or if you do not want to strain your eyes once again, peering into a small image. Golden the middle is the 7" display.

Resolution of the display installed in the intercom.

All other things being equal, a higher resolution provides a smoother and more detailed image, but it does affect the cost of the screen. In addition, all the benefits of high resolution are lost if the camera you are using does not support it. In general, this parameter is secondary: it is selected by the manufacturer based on the screen diagonal and the general functionality of the device, and for many screens it is not indicated at all - it is believed (and quite reasonably) that the resolution is in any case sufficient for its intended use. Therefore, there is no point in chasing a Full HD screen ; an HD display, or even an SD one, will be enough.

The number of outdoor panels that can be connected to the intercom at the same time.

The call panel is an external panel through which the guest sends a call to the owner of the intercom and communicates with him. Such a panel should be at each door "covered" by the intercom. This means that the number of supported outdoor panels corresponds to the maximum number of doors with which this model can be used. The simplest option is 1 calling panel, but in fact this is often not enough. Therefore, models that can block 2 doors at once are more popular — for example, the main and service entrances to the office. And in the most advanced intercoms, it may be possible to connect 4 calling panels at once, or even more.

The number of alarm inputs provided in the design of the intercom.

Such inputs allow the intercom to receive service signals from other elements of the security system — various sensors (motion, opening, temperature), cameras and video surveillance recorders, etc. This provides additional features for setting up the security system for certain events: for example, you can provide automatic activation of the video intercom camera when an opening sensor on an external wicket or gate is triggered. The specific functionality of alarm inputs for each model should be specified separately; however, anyway, such connectors allow you to increase automation and reduce dependence on the human factor. And the number of such inputs corresponds to the number of control components of the security system, which can be simultaneously connected to the intercom directly, without the use of additional equipment. Most often, it ranges from 3 to 8, and in some models it reaches one and a half dozen.

The number of alarm outputs provided for in the design of the intercom.

Alarm connectors are used to exchange service signals between individual components of the security system, most often to automatically turn on a particular function. The presence of alarm outputs in the intercom allows you to transmit control signals from it to other security devices — locks, spotlights, surveillance cameras, a siren, etc. For example, you can configure the system so that when you press the call button, not only the video intercom camera, but also external surveillance cameras.

The specific functionality of alarm outputs for each model should be specified separately; however, anyway, such connectors allow you to increase automation and reduce dependence on the human factor. And the number of such outputs corresponds to the number of controlled components of the security system, which can be simultaneously connected to the intercom directly, without the use of additional equipment. However, for a number of reasons, this number rarely exceeds 1.

Support for POE (Power Over Ethernet) is found only in models with a LAN connection. As the name suggests, it allows power to be supplied through the same network cable that connects the device to an intercom or other device. This is much more convenient than laying a separate wire for power or fiddling with autonomous power sources.