Allied Telesis Automatic MDIX Detection, Straight-through or Crossover Cabling

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 N o Yes Yes N o Yes No N o
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 Ye s Yes Yes Ye s Yes Yes Ye s
Standard TIA/EIA 568-
B-compliant Category 6
or 6a shielded cabling.
Yes Yes Ye s Yes Yes Ye s Yes Yes Ye s