MAC address table size
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.
Uplink
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.
Uplink type
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 Therefore, in this role, Fast Ethernet ports are used mainly in inexpensive and outdated models.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.
PoE outputs
The number of PoE-enabled outputs (see above) provided in the design of the switch. This number corresponds to the maximum number of PoE network devices that can be connected to this model at the same time.
Total PoE power
The total output power provided by the switch when powering devices using the PoE standard (see above).
This indicator usually corresponds to the sum of the powers of all outputs — that is, the power of one PoE port, multiplied by their total number. However, the power limits for one output and for the entire switch are somewhat different: if a load with a power equal to the output power of the power supply on this connector can be connected to a single connector, then the total power consumption of all devices connected via PoE should ideally not exceed 75% of the total power supply — this gives an additional guarantee in case of malfunctions. In fact, this means that all PoE outputs cannot be used “to the fullest” at the same time. For example, if there are two such outputs, and one is loaded at 100%, then the second can be loaded with a maximum of 50% — the total power consumption in this case will be the same 75% of the total output. Therefore,
a large total power is needed when using the device to the maximum.
Power consumption
Power consumed by network equipment during operation. Knowing the indicator of energy consumption, you can, for example, calculate the battery life of equipment from an uninterruptible power supply or choose a suitable “uninterruptible power supply”.
