Mount
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Desktop. Desktop routers include routers that do not use special rack mounts and are suitable for placement on any suitable surface — a table, shelf, etc. Although there are quite advanced models among desktop devices, however, most of them have relatively simple functionality and are designed for use in small networks where an abundance of equipment is not required.
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Rack mounted. Routers that are standard installed in a telecommunications rack are usually 19 "standard (although technically many of them can also be used as desktop ones, albeit with less convenience). Racks are used in extensive networks that require a large amount of equipment; accordingly, routers of this type in general, more powerful and advanced than the desktop, and are designed primarily for professional use.
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To the mast. Installation on a mast or other vertical structure — a tower, a pole, etc. Quite a rare form factor; It is mainly used in waterproof models designed for the possibility of working outdoors. Mobile network capable devices in this category may have a directional antenna to improve connectivity.
USB ports
The number of
USB ports provided in the design of the router. USB is a universal interface used in computer technology to connect peripheral devices for various purposes. One of its uses is to connect a 3G modem (if provided, see “Data entry (WAN-port)”), but this is not limited to this: in fact, the options for using USB ports directly depend only on the capabilities specified in the router firmware. So, in some models, you can connect a flash drive or an external hard drive to this connector — to update the firmware or even organize an FTP server directly on the router. And for other peripherals — printers, cameras, etc. — USB connection can be used to work as network devices (however, such functions are rare in standard firmware).
Security
The security features provided by the device. Among the most common features of this kind are
MAC address filtering,
web content filtering,
DoS protection,
antivirus,
antispam, and
DMZ. Here is a more detailed description for each item:
— MAC address filtering. The ability to restrict network access for individual devices using data about their MAC addresses. Recall that the MAC address is a unique identifier assigned to each network device. And this function allows, for example, to open Internet access only for certain computers in the office, or to limit the connection to a closed corporate network for devices that are not on the “white list”.
— Protection against DoS attacks. A set of tools (software and sometimes hardware) to protect against DoS attacks. DoS (Denial Of Service — "denial of service") in a simplified form can be described as an attack on a computer system using a huge number of requests that the system cannot handle; as a result, access is difficult or impossible for ordinary users. Protection against such attacks can be carried out, in particular, by filtering suspicious requests or limiting the number of responses to requests per unit of time. However, the specific functionality and features of this protection should be specified s
...eparately.
— Web content filtering. This function allows you to restrict or completely prohibit access of local computers to certain web resources. At the same time, filtering can be configured according to different criteria: by domain names, by categories (“adult” content, high traffic consumption, entertainment topics, etc.), by the type of content on the page (video, large images, certain scripts, etc.). n.) and others. Specific filtering features should be specified separately; however, anyway, this function allows you to set additional access rules. For example, it can be used to block access to non-work-related sites for employees in the office, or enable a parental filter on a home network.
— Antivirus. Antivirus — a tool for detecting and neutralizing malware — installed directly on the router. It is mainly used to analyze and filter network traffic, while many antiviruses are able to work in two directions — both for incoming and outgoing traffic. This allows not only to protect the network from outside attacks, but also to detect already infected local devices and prevent the distribution of confidential information, virus copies and other unwanted data. On the other hand, this feature increases the load on the router and can significantly slow down the connection speed. Therefore, it makes sense to use an antivirus on a router mainly in cases where individual devices on the network are poorly protected (or not protected at all), or if maximum protection is fundamentally important. It is also worth considering that the specific capabilities of the antivirus may be different, for each model they should be specified separately.
— Antispam. A built-in set of tools that allows you to analyze incoming mail traffic for spam and automatically filter these messages at the router level, preventing them from passing any further. This not only reduces the load on mail systems in the local network and facilitates mail filtering, but also has a positive effect on security: messages with malicious content simply do not reach the recipients. Note that when talking about antispam, they usually mean protection for classic email; for other communication methods (Viber, Telegram, etc.), such tools are not used for a number of reasons.
— DMZ. An abbreviation that stands for "demilitarized zone". By itself, this function allows you to create a segment in the local network that is open to external access; such a segment may host, for example, the company's Internet services. In its classic form, the DMZ is separated from the rest of the local network by a firewall, which provides the necessary security. At the same time, in some routers, this term may mean DMZ-host mode — a kind of "simplified version". When operating in this mode, the server open for external access is not separated from the local network, which simplifies setup, but reduces security; therefore, the DMZ host is found mainly among low-cost models designed for home use and small businesses.PoE (output)
The PoE output(s) standard used by the router.
By itself, PoE (Power over Ethernet) technology allows you to transfer not only data over an Ethernet network cable, but also energy to power network devices. And
the presence of a PoE output (outputs) makes it possible to power such devices from the network connectors of the device. This eliminates the need to lay additional wires or use independent power sources, which is especially important for some equipment, such as external IP surveillance cameras. And when using the so-called splitters - devices that divide the PoE cable signal into purely network data and power power - using such outputs, you can also power equipment that does not initially support PoE (the main thing is that their power characteristics correspond to the capabilities of the switch).
As for PoE standards, they determine not just the overall power supply, but also compatibility with specific devices: the consumer must support the same standard as the router, otherwise normal operation will be impossible. Nowadays, including in the connectors of "switches", you can find two types of such standards - active (802.3af, 802.3at, 802.3bt) and passive (one, that's what it's called). The main difference between these varieties is that active PoE provides for matching the power source and load in terms of voltage and power, while passive PoE does not have such functions, and energy is supplied “as is”, witho
...ut adjustments. And here is a more detailed description of specific standards:
— 802.3af. The oldest active PoE power format in use today. It provides power at the power output up to 15 W (at the input of the consumer - up to 13 W), output voltage 44 - 57 V (at the input - 37 - 57 V) and power in a pair of supply wires up to 350 mA. Despite the "venerable age", it still continues to be widely used; so there are still quite a lot of routers that work only with 802.3af on sale (as of the end of 2021). However, it is worth considering that this standard immediately covers 4 so-called power classes (from 0 to 3), which differ in the maximum number of watts at the output and input. So when using 802.3af, it doesn't hurt to make sure that the output power will be sufficient for the selected load.
— 802.3af/at. A combination of two standards at once - the 802.3af described above and the newer 802.3at. The latter allows you to supply power up to 30 W (up to 25.5 W at the input of the powered device), uses a voltage of 50 - 57 V (42.5 - 57 V at the input), while the power in a pair of wires does not exceed 600 mA. Such a combination is relatively inexpensive, while it makes it possible to power a wide variety of external devices; so at the end of 2021, it is this type of PoE outputs that is most popular in routers.
— 802.3af/at, bt. Combination of 802.3af/at above with 802.3bt (PoE++, PoE type 3 or type 4). 802.3bt is the newest PoE power format; unlike earlier ones, it uses not 2, but 4 power wires, which allows you to supply very solid power to external devices - up to 71 V (at 90 W at the power output). Such capabilities are indispensable when supplying power to equipment with increased consumption - for example, external surveillance cameras, supplemented by heating systems. On the other hand, support for the 802.3bt standard significantly affects the cost of the device, and such a connection puts forward special requirements for the quality of cables. In addition, you need to keep in mind that this standard also includes the UPoE format created by Cisco and used in its equipment; and this standard (it is known as PoE type 3) has a more modest power - up to 60 W at the output (up to 51 W at the consumer's input). Yes, and the general standard 802.3bt includes two power classes - class 8, at which maximum performance is achieved, and class 7, where 75 watts are supplied to the output, and about 62 watts reach the consumer. So if you plan to use 802.3bt equipment, when choosing a router from this category, you must make sure that the power supply is enough for the connected devices to work properly.
— Passive. As already mentioned, the key difference between passive PoE and the active standards described above is that in this case the power output produces a strictly fixed power, without any automatic adjustments and adjustments for a specific device. The main advantage of this standard is its low cost: its implementation is much cheaper than active PoE, so such ports can be found even in entry-level routers. On the other hand, the aforementioned lack of auto-tuning makes it much more difficult to coordinate the equipment with each other - especially in light of the fact that different devices can differ markedly in the output / consumption of voltage and power (power). Because of this, when using passive PoE, you need to pay special attention to the compatibility of the source and load in these parameters. If there is no match, then in the best case (if the output voltage / power is lower than required), the power simply will not work, and in the worst case (with excess voltage / power), there is a high probability of overloads, overheating, and even breakdowns with fires - and such troubles may not occur immediately, but after a fairly long time. And it is definitely impossible to connect devices with active inputs to passive PoE outputs - for the same reasons.
In conclusion, it should be said that if the router has both an input with PoE support and several outputs with this function, then all the possibilities of such outputs, as a rule, can only be realized when the switch itself is powered from the outlet, and not from the PoE input. See "PoE Outputs" for details.
