Comparison MikroTik RB2011UiAS-IN vs MikroTik RB2011IL-IN

How the router connects to the Internet or other external network.

Almost all modern routers have ethernet network connectors for this purpose, however, in addition to them, other connection options can be provided — both wired ( ADSL, SFP / SFP + optics) and wireless (mobile access via 3G / 4G modem or SIM card). Here are the features of each option:

— Ethernet. A standard LAN network cable connector (“twisted pair”) is the most popular modern wired connection format in computer networks. Widely used both in "local" and to provide access to the Internet. This standard is somewhat inferior to SFP / SFP + (see below) in terms of speed and noise immunity, but it is much cheaper. The speed of work in modern versions of Ethernet can reach 10 Gbps (see "Connection speed of WAN ports"), theoretically, a further increase in throughput is possible.

— SFP / SFP + (optics). A connector for transmitting network traffic over a fiber optic cable. The main advantage of such a cable is complete insensitivity to electromagnetic interference. And data transfer rates can reach 2.7 Gbps in the original SFP and 16 Gbps in SFP+. At the same time, maintaining this standard is not cheap, and the benefits mentioned are not often needed in fact. Therefore, SFP / SFP + is found mainly...in mid-range and top-level routers.

— ADSL. Connecting to the Internet through a fixed telephone network using ADSL technology. The key advantage of this connection is the ability to use existing networks without laying additional wires; at the same time, Internet access is completely separated from telephone communication and traffic does not interfere with voice calls. On the other hand, the bandwidth of ADSL is very low by modern standards (less than 24 Mbps), moreover, the data transmission speed is noticeably lower than the reception speed. This can create problems for video communication and some other specific tasks. So nowadays ADSL is used less and less.

— 3G/4G modem (USB). Internet connection via mobile network using a separate 3G or 4G modem connected to the USB port. This feature can be useful where there is no full-fledged wired connection (for example, in rural areas), and also as a fallback option in case the main communication channel fails. And the type of network supported depends mainly on the modem used (the compatibility of the router with different models needs to be specified separately, but most often there are no problems with this). As for specific types of networks, most 3G modems work in UMTS networks (the same ones that are massively used by mobile phones); the data transfer rate in such networks can reach 75 Mbit / s (however, usually it is much lower). Less common are 3G modems for EV-DO networks based on CDMA — this standard has lower speeds (up to 14.7 Mbps) and not as extensive coverage as UMTS, however, both the equipment and the connection itself can be cheaper. And the designation "4G" means only one type of networks — LTE; it provides speeds up to 173 Mbps, but is not as widespread as 3G.

— SIM card. Another option for connecting to the Internet via mobile networks is its own SIM card slot provided in the design of the router. This option is convenient because you do not need to buy an additional device (modem) for mobile Internet — you just need to purchase an operator's SIM card. On the other hand, due to the built-in mobile communication modules, such routers themselves are more expensive than analogues for USB modems. In addition, the connectivity options in them are limited by the characteristics of the module: for example, a router for 3G networks will not be able to fully use 4G networks (whereas a USB modem can usually be changed to a more advanced one). As a result, this option is relatively rare in modern equipment.

The number of optical network ports of the SFP standard provided in the design of the device. We emphasize that we are talking about "ordinary" SFPs; SFP+ data is usually listed separately.

Specifically, in switches, the marking “SFP” usually means a connector for fiber with a connection speed of 1 Gbps. Technically, this is not much compared to RJ-45 speeds; however, this connection format has a number of advantages. One of the main ones is a greater effective range: the mentioned gigabit standard works with a cable length of up to 550 m, and by the standards of optical fiber, this is still very little. True, the cable itself is sensitive to kinks and requires quite delicate handling; on the other hand, it is completely immune to electromagnetic interference. On the other hand, in general, the SFP format is noticeably less popular in network equipment than RJ-45; therefore, there are few ports of this type even in advanced devices ( 1 port or 2 ports, less often more). It is also worth considering that there may be so-called combo connectors that combine SFP and RJ-45; the presence of such ports is specified in the notes, they are taken into account both in the calculation of RJ-45 and in the calculation of SFP.

The presence of a console port in the router. This connector is used to control the device settings from a separate computer, which plays the role of a control panel — a console. The advantage of this format of operation is that access to the functions of the router does not depend on the state of the network; in addition, special utilities can be used on the console that provide more extensive capabilities than a regular web interface or network protocols (see "Management"). An RS-232 connector is often used as a console port, but in modern routers this role can also be played by a separate Ethernet input (not used for any other purpose).

The model of the processor installed in the device. The processor is responsible for processing network traffic and running software. Knowing its name, you can get more detailed data on the speed capabilities of the equipment and understand how much such a powerful or, on the contrary, mediocre element is needed on board. In new models of Wi-Fi equipment, coprocessors or so-called NPU modules are often installed, which relieve the load from the main processor.

The number of cores in the processor installed in the device. The core in this case refers to the part of the processor that executes one thread of instructions. Accordingly, the presence of multiple cores allows you to work with multiple threads simultaneously, which has a positive effect on performance.

The number of cycles per second that the processor produces in its normal operating mode. A clock is a single electrical impulse used to process data and synchronize the processor with the rest of the computer system. Different operations may require fractions of a clock or several clocks, but anyway, the clock frequency is one of the main parameters characterizing the performance and speed of the processor — all other things being equal, a processor with a higher clock frequency will work faster and better cope with significant loads.

The amount of random access memory (RAM) provided in the device. The amount of "RAM" is one of the indicators of the power of the device: the larger it is, the higher the speed and the better the device will cope with "heavy" tasks.

The amount of memory allocated for the operation of the operating system on board the device. It stores the OS and the control programme. Note that Flash memory is not available for use by the end user.

The standard for the PoE input provided in the device.

By itself, PoE (Power over Ethernet) technology makes it possible to transfer not only data over an Ethernet network cable, but also energy to power network devices. And the presence of a PoE input allows the router itself to receive power in a similar way. Note that there are special devices - the so-called PoE injectors - that allow you to add power to a regular network signal (that is, add PoE support to equipment that does not initially have such a function).

As for the PoE standards, they determine both the power supply and the main possibilities for coordinating the power source with the consumer - both must support the same standard, otherwise normal operation will be impossible. At the same time, formats that are marked like “802.3*” are called active; their common feature is that when a load is connected, the power source first “interrogates” it, checking whether the powered device complies with the requirements of the corresponding standard, and if so, what kind of power should be supplied to it. There is no such feature in the passive standard. And here is a more detailed description of specific options:

— 802.3at. A standard originally released back in 2009 and known as PoE +, or PoE type 2. The standard power received at this input is 25.5 W, with a voltage of 42.5 to 57 V and a pair power of up to 600 mA.

— 802.3af/at. This...marking means that the PoE input supports both the 802.3at standard described above and the earlier 802.3af (PoE type 1). The second format is noticeably more modest in terms of capabilities: it provides power at the power input up to 13 W, input voltage 37 - 57 V and power in a pair of power wires up to 350 mA. Despite their "venerable age", many devices with 802.3af outputs are still in use today; so for the power input of the router, compatibility with this standard may not be superfluous. We only note that 802.3af covers as many as four so-called power classes (from 0 to 3), which differ in the specific number of watts at the output and input. So when connecting power from a device with this PoE standard, it does not hurt to further clarify compatibility by power class.

— Passive. The most simple and inexpensive standard, designed to be used mainly in entry-level equipment (since the implementation of active PoE standards is generally expensive). As mentioned above, the key difference from the formats described above is that the power supply supplies energy "as is" - with a strictly fixed voltage and power, without checking the characteristics of the load and without adjusting to it. This is what ensures low price and availability. On the other hand, when using a passive PoE input, care must be taken to ensure that the voltage and power of the power supply match the characteristics of the router; and such coordination can be quite difficult in light of the fact that the passive standard does not have strictly defined standards even for voltage, not to mention power. At the same time, the inconsistency leads to the fact that in the best case (if the output voltage / power is lower than tech required for the load), 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 - moreover such troubles may not occur immediately, but after a fairly considerable time. So you should pay attention to this option first of all in cases where simplicity and accessibility are more important than advanced power supply standards. At the same time, we note that some switches, which, in addition to the passive input, also have a passive PoE output, allow “cascade” connection - in the form of a serial chain of several devices powered by one external source (the main thing is that this source has enough power).

Separately, we emphasize that you should not try to connect an active power source to a passive input, and even more so vice versa. In the first case, the device simply will not pass the test that is carried out before power is applied, and the power will not turn on. And in the second case, serious failures and even accidents are possible: a passive power source supplies energy immediately, without checking the characteristics of the powered device, which creates the risk of overloads if the operating parameters do not match.