Connections
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 a
...nd 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.SFP (optics)
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.
CPU
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.
CPU cores
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.
RAM
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.
Flash memory
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.
