When we are going to wire our house, office or business, we have to think about the limitation of length of Ethernet network cables. While optical fiber can have a maximum distance of several kilometers, in Ethernet technology this is much more limited. Depending on the standard we are going to use, such as 1000BASE-T, 2.5GBASE-T, 5GBASE-T or 10GBASE-T, we have requirements for the cable category and the maximum length, so it is necessary that you comply with the maximum distance if you don’t want to have connectivity issues.
Maximum distances according to standards
Depending on the 802.3 standard used and the category of cables used, we have a maximum distance that we must use to comply with the regulations. However, our recommendation is to never reach the limits and put a switch at intermediate distances to regenerate the signal, this way your network will be much more reliable, especially since it is possible that we go very far , because it also enters external interference and the quality of the network cable are at stake.
- 1000BASE-T: the typical standard 1000BASE-T or also called “Gigabit Ethernet” allows us to have a 100 meter maximum distance with Cat5e or better cabling. That’s what the theory says, but once the corresponding cable is installed, it is strongly recommended to test it electrically and check that it works correctly, so as not to have sporadic disconnection problems when using the network. This maximum distance is per segment, i.e. from switch to switch, for example. A very important detail is that we could have a greater distance by connecting several switches in cascade, to cover a greater distance in case it is necessary.
- 2.5GBASE-T: This standard, also known as 2.5G Multigigabit, allows us to have a maximum distance up to 100 meters per segment with Cat5e or better cabling. In this case we would be the same as in the 1000BASE-T standard, also if you want to increase this maximum distance, because you could add several switches to go further without problems.
- 5GBASE-T: This standard is also known as 5G Multigigabit, in this case it allows us to have a maximum distance up to 100 meters per segment with Cat 6 cabling or better. In this case it is mandatory that the network cable be Cat 6 or higher, it does not happen as in the previous ones that it was enough to use Cat 5e. In this case, we could also increase the distance by connecting several switches between the two, or some kind of repeater.
- 10GBASE-T: this standard allows us to have a maximum distance up to 100 meters per segment if we use Cat 6A or higher cabling. When using Cat 6 cabling, we have several limitations regarding the maximum distance. In case of unfavorable crosstalk we will be able to have a maximum distance of 37 meters, in case of favorable crosstalk we can reach up to 55 meters. However, the quality of cable from different manufacturers cannot be guaranteed, so it would be best to electrically test the cable once installed.
As we explained before, it is strongly recommended to electrically test the cables before putting the whole network in production, in order to verify that everything is working correctly. A very important detail is that currently there are PoE switches oriented to video surveillance that allow us to cover a distance of up to 250 meters in length in the same Ethernet segment, yes, at a speed of 10 Mbps using the standard 10BASE-T.
This 10Mbps throughput is sufficient for this type of CCTV use, as long as the camera doesn’t have too much throughput, of course. In addition, we could also install extenders with 100 meters of range for each network segment, this way we can further increase the distance, for example, in the case of the D-Link DSS-100E-9P switch, we can have up to 250 meters of distance, and purchase the D-Link DPE-302GE to extend that distance an additional 100 meters, with a maximum of 650 meters in total.