Fast Ethernet
The number of standard RJ-45 network connectors in the Fast Ethernet format provided in the design of the switch.
Fast Ethernet is the most modest of the wired connection formats over a twisted-pair network cable nowadays — it provides data transfer rates up to 100 Mbps. However, even this speed is often enough for relatively simple tasks that are not associated with large amounts of data. Therefore, this interface is still widely used in modern switches.
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 Fast 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.
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”.
Operating temperature
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.
