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Първоначално написано от СветлинСтаев
(Мнение309375)
10/100 ме устройва, а все пак има ли опция за разделяне на две връзки през 1 UTP кабел и да се прекара гигабит?
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1000BASE-T
An Intel 82574L Gigabit Ethernet NIC, PCI Express x1 card
1000BASE-T (also known as IEEE 802.3ab) is a standard for gigabit Ethernet over copper wiring.
Each 1000BASE-T network segment can be a maximum length of 100 meters (330 feet), and must use Category 5 cable or better (including Cat 5e and Cat 6).
Autonegotiation is a requirement for using 1000BASE-T[9] according to Section 28D.5 Extensions required for Clause40 (1000BASE-T).[10] At least the clock source has to be negotiated, as one endpoint must be master and the other endpoint must be slave.
In a departure from both 10BASE-T and 100BASE-TX, 1000BASE-T uses all four cable pairs for simultaneous transmission in both directions through the use of adaptive equalization and a 5-level pulse amplitude modulation (PAM-5) technique. The symbol rate is identical to that of 100BASE-TX (125 Mbaud) and the noise immunity of the 5-level signaling is also identical to that of the 3-level signaling in 100BASE-TX, since 1000BASE-T uses 4-dimensional trellis coded modulation (TCM) to achieve a 6 dB coding gain across the 4 pairs.
Since negotiation takes place on only two pairs, if two gigabit devices are connected through a cable with only two pairs, the devices will successfully choose 'gigabit' as the highest common denominator (HCD), but the link will never come up. Most gigabit physical devices have a specific register to diagnose this behaviour. Some drivers offer an "Ethernet@Wirespeed" option where this situation leads to a slower yet functional connection.[11]
Или казано с две думи - НЯМА ОПЦИЯ |
