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Automatic mdix detection, Straight-through or crossover cabling – Allied Telesis SwitchBlade x3112 User Manual

Page 37

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SwitchBlade x3112 Installation Guide

37

Automatic MDIX

Detection

The 10/100/1000 Mbps twisted-pair ports on the AT-SBx31GT24, AT-
SBx31GT40, and AT-SBx31GP24 Line Cards are IEEE 802.3ab compliant
and feature automatic MDIX detection when operating at 10 or 100 Mbps.
(Automatic MDIX detection does not apply to 1000 Mbps.) This feature
automatically configures the ports to MDI or MDI-X depending on the
wiring configurations of the end nodes.

You may not disable automatic MDIX detection on the ports. For automatic
MDIX detection to work properly, it must also be present on the network
devices. Ports connected to network devices that do not support automatic
MDIX detection default to MDIX.

Straight-through

or Crossover

Cabling

Here are the guidelines on whether to use straight-through or crossover
cables to connect network devices to the line cards:

You may use straight-through cables on ports that are connected
to network devices that operate at 1000 Mbps.

Table 2. Twisted Pair Cable for the AT-SBx31GP24 Line Card

Cable Type

10Mbps

100Mbps

1000Mbps

Non-

PoE

PoE

PoE+

Non-

PoE

PoE

PoE+

Non-

PoE

PoE

PoE+

Standard TIA/EIA 568-
B-compliant Category 3
shielded or unshielded
cabling with 100 ohm
impedance and a
frequency of 16 MHz.

Yes

No

No

Yes

No

No

No

No

No

Standard TIA/EIA 568-
A-compliant Category 5
shielded or unshielded
cabling with 100 ohm
impedance and a
frequency of 100 MHz.

Yes

Yes

No

Yes

Yes

No

Yes

No

No

Standard TIA/EIA 568-
B-compliant Enhanced
Category 5 (Cat 5e)
shielded or unshielded
cabling with 100 ohm
impedance and a
frequency of 100 MHz.

Yes

Yes

Yes

Yes

Yes

Yes

Yes

Yes

Yes

Standard TIA/EIA 568-
B-compliant Category 6
or 6a shielded cabling.

Yes

Yes

Yes

Yes

Yes

Yes

Yes

Yes

Yes