Comparison D-Link DIR-879 vs D-Link DIR-890L

Methods for connecting to the Internet (or other external network, such as in bridge mode) supported by the device.

The classic, most common version of such a connection nowadays is LAN (Ethernet), but this is not limited to this. A wired connection can also be made via ADSL or SFP fiber, and wirelessly via mobile networks (using a SIM card, SIM card 5G or an external modem for 3G or 4G), as well as via Wi-Fi. Here is a more detailed description of each option:

— Ethernet (RJ45). Classic wired connection via a network cable via an RJ-45 connector. Also known as "LAN", although this designation is not entirely correct. Nowadays, it is one of the most common methods of wired Internet connection, and is also widely used in local networks. This is due to the fact that the speed of Ethernet is actually limited only by the capabilities of network controllers; at the same time, even the simplest modules support up to 100 Mbps, and in advanced equipment this value can reach 10 Gbps.

— ADSL. A technology primarily used for wired Internet connections over existing landline telephone lines. This is its main advantage — you can use ready-made lines without fiddling with laying numerous addi...tional wires; at the same time, ADSL works independently of telephone calls and does not interfere with them. At the same time, the speed of such a connection is noticeably lower than via Ethernet — even in advanced equipment it does not exceed 24 Mbps. In addition, ADSL traffic is distributed asymmetrically: full speed is achieved only when working for reception, data transmission speed is much lower, which creates problems for video communication and some other tasks. So nowadays, ADSL is gradually being replaced by more advanced standards, although the complete disappearance of this technology is still far away.

— Wi-Fi. Connect to an external data source via Wi-Fi. By definition, this format of operation is used by Wi-Fi adapters (see "Device type"), as well as by most MESH equipment. (However, if the MESH system package includes both nodes and the main control device for them, then the WAN input can be specified for the control device, and often this is not Wi-Fi). Also, this type of data input can be provided in other types of equipment — in particular, routers and access points (for example, to work in bridge or repeater mode).

— 3G modem (USB). Internet connection via 3G mobile network using a separate external modem connected to the USB port. Most often, we are talking about UMTS networks (the development of GSM mobile communications), the most common in Europe and the post-Soviet space; however, it may also be possible to use modems for CDMA networks (EV-DO technology). These nuances, as well as compatibility with specific modem models, need to be clarified separately. However, anyway, 3G may be a good option for situations where a wired Internet connection is difficult or impossible, such as in the private sector. In addition, some Wi-Fi devices with this feature are equipped with autonomous power supplies and can even be used on the go. The data transfer speed of 3G is close to broadband wired connection (from 2 to 70 Mbps with a normal signal, depending on the specific technology); however, it is less than in 4G networks (see below), but 3G coverage is more extensive, and equipment for this standard is cheaper.

— 4G (LTE) modem (USB). Internet connection via 4G mobile network (LTE) using a separate external modem connected to the USB port. The main features are similar to the 3G connection described above, adjusted for the fact that in this case more advanced fourth-generation networks are used. The data transfer rate in such networks reaches about 150 Mbps; they are not as widespread as 3G-connection, but soon we can expect a change in the situation. In addition, it should be noted that in Europe and the post-Soviet space, LTE networks are usually deployed on the basis of 3G UMTS and GSM networks; so in the absence of full-fledged 4G coverage, modems for such networks can work according to the 3G and even GSM standard.

— SIM card. Connecting to the Internet via a mobile network using a mobile operator's SIM card installed directly in the device. The specific type of supported networks depends both on the capabilities of the router and on the conditions of a particular mobile operator; however, all such equipment is compatible with at least 3G networks, and often 4G as well. The features of these networks are described in detail above (you can also read about the advantages of a mobile Internet connection there). This option is convenient because it allows you to do without a separate USB modem — you just need to purchase a SIM card, the cost of which is negligible. In addition, the use of "sim cards" has a positive effect on compactness and ease of carrying. On the other hand, the built-in mobile communication module significantly affects the overall cost — and you will have to pay for it anyway (whereas a model with support for external modems does not have to be bought immediately with a modem, such devices usually allow wired connection). Therefore, you should pay attention to this option if you initially plan to connect to the Internet through mobile networks.

- SIM card (5G). The ability to operate Wi-Fi equipment in high-speed 5G mobile networks with a peak bandwidth of up to 20 Gbps for reception and up to 10 Gbps for data transmission. Implemented via a SIM card with appropriate 5G support. This standard reduces power consumption compared to previous versions, and it also uses a number of complex solutions aimed at improving the reliability and overall quality of communication - in particular, multi-element antenna arrays (Massive MIMO) and beamforming technologies (Beamforming).

— SFP (optics). Connection via fiber optic cable of the SFP standard. Such a connection can be carried out at high speeds (measured in gigabytes per second), and the fiber, unlike the Ethernet cable, is practically insensitive to external interference. On the other hand, the support of this standard is not cheap, and its capabilities are unnecessary for domestic use. Therefore, SFP is found mainly in professional-level Wi-Fi devices.

The number of wireless bands and channels supported by the router. Specified only for models that work with more than one range.

— Dual-band (2.4 GHz and 5 GHz). Devices that simultaneously support two popular communication bands — 2.4 GHz and 5 GHz — in the "one communication channel per band" format. This ensures compatibility with most Wi-Fi standards (see above), and in some cases also has a positive effect on the quality of communication. For example, a Wi-Fi adapter (see "Device Type") with this feature may provide the ability to evaluate the load on both bands and automatically select the less loaded one.

— Three-channel (2.4 GHz and 5 GHz in 2 channels). An improved version of the dual-band operation format: in the 5 GHz band, communication is carried out on two channels. This allows, for example, to “raise” three wireless connection channels on one router at once (three visible networks in the list of wireless networks) and achieve even higher throughput. The advantages of this format are especially noticeable when the router works simultaneously with several wireless devices.

— Tri-band (2.4 GHz, 5 GHz, 60 GHz). The most "omnivorous" type of modern Wi-Fi equipment, compatible with all popular standards — from the outdated 802.11 b / g to the relatively new 802.11 ad. Also, the abundance of ranges contributes to an increase in spee...d, especially when working with multi-range devices.

The number of USB 2.0 ports provided in the design of the device.

USB in this case plays the role of a universal interface for connecting peripheral devices to the router. The specific USB devices supported and how they are used may vary. Examples include working with a flash drive that plays the role of a drive for working in FTP or file server mode (see "Functions / Capabilities"), connecting to a printer in print server mode(see ibid), connecting a 3G modem (See "Data input (WAN-port)"), etc.

Specifically, USB 2.0 allows you to transfer data at speeds up to 480 Mbps. This is noticeably less than that of more advanced standards (starting with USB 3.2 gen1 described below), and the power supply of such connectors is low. However, even such characteristics are often quite enough, taking into account the specifics of the use of Wi-Fi devices. In addition, peripherals for newer versions can also be connected to the USB 2.0 port — the main thing is that the power supply is enough. Therefore, although this standard is considered obsolete, it is still widely used in modern wireless equipment. There are even models that provide 2 or even more USB 2.0 ports; this allows you to simultaneously use several external devices at once — for example, a 3G modem and a USB flash drive.

The number of USB 3.2 gen1 ports provided in the design of the device.

USB in this case plays the role of a universal interface for connecting peripheral devices to the router. The specific USB devices supported and how they are used may vary. Examples include working with a flash drive that plays the role of a drive for working in FTP or file server mode (see "Functions / Capabilities"), connecting to a printer in print server mode (see ibid), connecting a 3G modem (See "Data input (WAN-port)"), etc.

Specifically, the version of USB 3.2 gen1 (formerly known as USB 3.0 and USB 3.1 gen1) is the direct successor to USB 2.0, which, in particular, has increased by 10 times (up to 4.8 Gbps) the maximum data transfer rate and increased power supply. However despite the general popularity, this standard is still relatively rare in Wi-Fi devices — USB 2.0 is enough for many tasks. However, the situation is gradually changing; and among advanced hardware such as gaming routers, you can find solutions with 2 or more USB 3.2 gen1 ports.

The total number of antennas (of all types — see below) provided in the design of the device.

In modern Wi-Fi equipment, this indicator can be different: in addition to the simplest devices with 1 antenna, there are models where this number is 2, 3, 4 and even more. The point of using multiple antennas is twofold. Firstly, if there are several external devices per antenna, they have to share the bandwidth among themselves, and the actual communication speed for each subscriber drops accordingly. Secondly, such a design may also be required when communicating with one external device — to work with MU-MIMO technology (see below), which allows you to fully realize the capabilities of modern Wi-Fi standards.

Anyway, more antennas, usually, means a more advanced and functional device. On the other hand, this parameter significantly affects the cost; so specifically looking for equipment with numerous antennas makes sense mainly when the speed and stability of communication are critical.

Note that antennas intended for mobile communications may also be considered in this clause. So when choosing a model with support for mobile networks, it's ok to clarify this point.

The total number of antennas in the router that are responsible for communication in the 2.4 GHz band. For details about the number of antennas, see "Total antennas", about the range — "Frequency range".

The total number of antennas in the router that are responsible for communication in the 5 GHz band. For details about the number of antennas, see "Total antennas", about the range — "Frequency range".

The total number of antennas in the router that can operate on both 5 GHz and 2.4 GHz frequencies. For details about the number of antennas, see "Total antennas", about the range — "Frequency range".

Rated power of the Wi-Fi transmitter used in the device. If multiple bands are supported (see “Ranges of operation”) the power for different frequencies may be different, for such cases the maximum value is indicated here.

The total transmitting power provided by the device directly depends on this parameter. This power can be calculated by adding the transmitter power and the antenna gain (see above): for example, a 20 dBm transmitter coupled with a 5 dBi antenna results in a total power of 25 dBm (in the main antenna coverage area). For simple domestic use (for example, buying a router in a small apartment), such details are not required, but in the professional field it often becomes necessary to use wireless devices of a strictly defined power. Detailed recommendations on this matter for different situations can be found in special sources, but here we note that the total value of 26 dBm or more allows the device to be classified as equipment with a powerful transmitter. At the same time, such capabilities are not always required in fact: excessive power can create a lot of interference both for surrounding devices and for the transmitter itself (especially in urban and other similar conditions), as well as degrade the quality of the connection with low-power electronics. And for effective communication over a long distance, both the equipment itself and external devices must have the appropriate power (which is far from alway...s achievable). So, when choosing, you should not chase the maximum number of decibels, but take into account the recommendations for a particular case; in addition, a Wi-Fi amplifier or MESH system often turns out to be a good alternative to a powerful transmitter.