IEEE 802.3 40GBase-T

The IEEE working group802.3bq deals with the topic of 40 Gigabit Ethernet and 25 Gigabit Ethernet over a four-pair TP cable ofcategory 8. 10GBase-T forms the basis of 40GBase-T.

The 40GBase-T interface has a spectral bandwidth of 1,600 MHz and uses four twisted-pair cables. These Category 8 and Link Class"G" TP cables have both shielding for each individual pair of wires and overall shielding and are known as Screened Shielded Twisted Pair (S/ STP) or Screened Foiled Twisted Pair (S/ FTP). The two cables are terminated with two RJ45 connectors.

40GBase-T can only bridge a range of 30 m due to the high demands on the attenuation budget. There are four channelsin each direction. Point-to-point connections can be established via structured cabling. Because of the short distances, 40GBase-T is mainly suitable for use in data centers and server rooms, including for cabling between the servers and the ToR or EoR switches.