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Copper transceiver modules
Copper transceiver modules transmit signals over Category-5, -5e, -6, and -6a unshielded twisted pair (UTP).
UTP transmission cover shorter distances than fiber transmission and can be used in small-sized networks
only. 10G over twisted pair requires the use of Category 6 and 6a.
Copper transceivers are supported in 1G SFP and 10G SFP+ ports where listed in the compatibility tables.
Transmission distance
Through UTP cables, signals can be transmitted over a distance of 100 m (328.08 ft.) only. This behavior
occurs because signals attenuate during transmission through the UTP cables.
Attenuation refers to the dissipation of the power of a transmitted signal as it travels over a cable.
Attenuation occurs because signal transmission suffers certain resistance from the cable, which weakens
the signals as they travel over the cable. When signals are transmitted over a long distance, signal strength
decreases significantly, causing the signal-to-noise ratio to drop below the accepted level. This decrease
makes it impossible to distinguish between signals and noise, which results in data loss.
Patch panel and punch down blocks also affect attenuation; that is, they can be a source of issues resulting
in shorter distances or data loss.
10GBASE-T connections require Category 6a as a minimum for proper 10G speeds up to the 100m distance
dictated by the IEEE 802.3ae standard for a fixed 10GBASE-T port. The JL563A transceiver has a limit of 30m
max distance due to limited power available to the transceiver (vs a fixed 10GBASE-T port). Anything less
(Cat 6, 5e, 5) will compromise the distance that 10G over copper can achieve.
Shielded Twisted Pair (STP) Cat 6a cable is required for full support when using the 10GBase-T transceiver
(JL563A) supported only on the 8400, 8320, and 8325 switch models. Use of STP prevents EMI events from
affecting data traffic carried on the wire - known as Crosstalk or Alien Crosstalk. Large EMI events from
electronically noisy environments may be coupled onto unshielded cabling and cause temporary packet
errors. Fixed 10G ports have designs to counteract these types of bit error conditions, that the 10GBASE-T
transceiver cannot counteract consistently. Using STP Cat6a cables mitigate the errors significantly. All
packet loss errors observed in extensive testing are considered recoverable by the host system with the
JL563A transceiver.
Connector
Registered Jack-45 (RJ-45) twisted-pair connectors are used as connectors for copper transceiver modules.
Figure 4: RJ-45 connector
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ArubaOS-Switch and ArubaOS-CX Transceiver Guide
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