Comparison MikroTik CRS328-4C-20S-4S+RM vs MikroTik CRS326-24G-2S+RM

The maximum number of MAC addresses that can be stored in the Switch's memory at the same time. Specified in thousands, for example, 8K — 8K.

Recall that the MAC address is the unique address of each individual network device used in physical routing (at layer 2 of the OSI network model). Switches of all types work with such addresses. And it is worth choosing a switch according to the size of the table, taking into account the maximum number of devices that are supposed to be used with it (including based on the possible expansion of the network). If the table is not enough, the switch will overwrite new addresses over the old ones, which can noticeably slow down the work.

The number of standard Gigabit Ethernet RJ-45 network connectors provided in the design of the switch.

As the name suggests, these connectors provide data transfer rates up to 1 Gbps. Initially, Gigabit Ethernet was considered a professional standard, and even now the real needs for such speeds arise mainly when performing special tasks. Nevertheless, even relatively inexpensive computers are now equipped with gigabit network adapters, not to mention more advanced technology.

As for the number of connectors, it corresponds to the number of network devices that can be connected to the "switch" directly, without the use of additional equipment. In the case of Gigabit Ethernet, the number of connectors up to 10 inclusive is considered relatively small, from 10 to 25 — average, and the presence of more than 25 ports of this type is typical for professional-level models. At the same time, it is worth noting that in some "switches" individual connectors of this type are combined with optical SFP or SFP + (see below). Such connectors are marked "combo" and are taken into account both in the RJ-45 count and in the SFP/SFP+ count.

The number of optical network ports of the SFP standard provided in the design of the switch. 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 used in switches works with a cable length of up to 550 m, and by the standards of 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. So, solutions for 2 or 4 SFP connectors are most widely used, although there are more - 6, 8, or even 10 or more. It is also worth considering that the so-called combo connectors can be used in switches, combining 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.

To clarify, Uplink inputs also often use this type of connector; however, their...number is specified separately (see below).

The number of Uplink connectors provided in the design of the switch.

“Uplink” in this case is not a type, but a connector specialization: this is the name of the network interface through which the switch (and network devices connected to it) communicate with external networks (including the Internet) or network segments. In other words, this is a kind of "gate" through which all traffic from the network segment served by the switch is transmitted further. Uplink, in particular, can be used to connect to a similar "switch" (for horizontal network expansion) or to a higher level device (like a core switch).

Accordingly, the number of Uplink connectors is the maximum number of external connections that the switch can provide without using additional equipment. The specific type of such a connector may be different, but this is usually one of the varieties of LAN or SFP; see "Uplink type" for details.

The type of connector(s) used as the Uplink interface on the switch.

For more information about such an interface, see above; Here we note that the same network ports are usually used as Uplink as for connecting individual devices to the switch. Here are the main options for such connectors:

— Fast Ethernet — LAN network connector (for twisted pair cables) supporting speeds up to 100 Mbit/s. This speed is considered low by modern standards, while the Uplink port places increased demands on throughput - after all, traffic from all devices served by the switch passes through it. Therefore, in this role, Fast Ethernet ports are used mainly in inexpensive and outdated models.

— Gigabit Ethernet — LAN connector supporting speeds up to 1 Gbit/s. This speed is often sufficient even for a fairly extensive network, while the connectors themselves are relatively inexpensive.

— 2.5 Gigabit Ethernet — LAN connector supporting speeds up to 2.5 Gbit/s.

— 10Gigabit Ethernet — LAN connector supporting speeds up to 10 Gbit/s. Such features allow you to work comfortably even with very large volumes of traffic, but they significantly affect the price of the switch. Therefore, this option is rare, mainly in high-end models.

— SFP. A connector for a fiber optic cable that supports speeds of about 1 Gbit/s. At the same time, over Gigabit Ethernet, which has a similar throughput, this connector has one noticeable advantage - a...longer connection range (usually up to 550 m).

- SFP+. Development of the SFP standard described above. Switches usually provide a connection speed of 10 Gbit/s; like the original standard, it noticeably exceeds the effective range of an Ethernet connection. On the other hand, the real need for such speeds does not arise so often, and SFP+ is quite expensive. Therefore, the presence of such Uplink connectors is typical mainly for high-end models with a large number of ports.

- SFP28. Another development of SFP with increased throughput up to 25 Gbit/s.

- QSFP / QSFP+. The fastest SFPs up to 40 Gbit/s.

Note also that the connectors described above (except perhaps Fast Ethernet) are rarely used as the only type of Uplink input. Combinations of electrical and fiber optic ports—SFP/Gigabit Ethernet and SFP+/10Gigabit Ethernet—have become noticeably more widespread. This provides versatility in connection, allowing you to use the most convenient type of cable in a given situation; and if necessary, of course, you can use all Uplink inputs at once. However, it is worth considering that in some models, Ethernet and SFP interfaces can be combined in one physical connector. So before purchasing, it doesn’t hurt to clarify this nuance separately.

There are also switches that use a combination of two types of SFP - SFP/SFP+; however, there are few such models and they are mainly of the professional level.

— Built-in. The built-in power supply does not take up space on the outside, but can significantly increase the size and weight of the entire switch. Because of this, this option is quite rare — mainly among rack-mount models (see "Form factor"), where an external unit can create significant inconvenience, as well as among the most powerful desktop switches, for which restrictions on dimensions and weight is not critical.

— External. Theoretically , an external power supply requires additional space, and therefore is not as convenient as an internal one. In fact, most blocks of this type are quite compact in size and are equipped with “plugs” for sockets right on the case — in other words, the block is installed on a socket, and from there the wire stretches to the switch. And the absence of power circuits and transformers inside the case has a positive effect on compactness. Thanks to all this, this option is very popular among desktop models (see "Form factor"), primarily entry-level and mid-level.

— No BP. The absence of a power supply both in the design and in the delivery set is a rather rare case found in three types of switches. The first variety is models that use PoE power (see above) and do not require separate power sources. PoE power is relatively small, so relatively simple devices with a small number of ports fall into this category. The second variety is professional switc...hes, the power supplies for which are sold as separately installed internal modules; such equipment may even provide the possibility of using two PSUs simultaneously (main and backup) and hot-swapping them. The third type — switches with installation on a DIN rail (see "Form factor") and having terminals for connecting a specialized external power source.

The amount of voltage required by the switch for uninterrupted operation. The power supply voltage of network equipment can vary from 5 V to 230 V, which allows you to power compatible devices from either a low-voltage USB socket on your computer or a standard household outlet. Values in the middle assume that the switch is powered by the appropriate power supply.

The range of operating temperatures allowed for the switch, in other words, the air temperature at which the device is guaranteed to remain operational.

All modern switches are able to normally endure conditions that are comfortable for a person. Therefore, you should pay attention to this indicator, first of all, in cases where the conditions at the installation site of the switch will differ markedly from home / office; a typical example is the placement of ISP equipment in the attic of a multi-storey building. At the same time, special attention should be paid to the lower limit of the temperature range — not every device is able to operate at sub-zero temperatures. If we talk about specific numbers, then for an unheated room frost resistance is desirable at least at the level of -5 °C, and ideally — — 20 °C(although, of course, this also depends on the climate).

Also note that, in addition to temperature, most switches have restrictions on the relative humidity of the air; these restrictions are usually specified in the documentation.