Auto Mdi/Mdi-X; Port Pinouts - Allied Telesis AT-CM20x Series Reference Manual

Chapter 1: Converteon™ Fast Ethernet and Gigabit Ethernet Line Cards
Auto MDI/
MDI-X

Port Pinouts

The 10/100Base-TX twisted pair ports are auto-MDI/MDI-X. They
automatically configure themselves as either MDI or MDI-X, depending on
the configuration of the port on the end node. This feature allows you to
use either straight-through or crossover twisted pair cables to connect
devices to the ports.
Note
The auto-MDI/MDI-X feature on a port is available only when the
port is set to Auto-Negotiation. If you disable Auto-Negotiation and
set a port's speed and duplex mode manually, the port defaults to
MDI-X. For instructions on configuring a port, refer to the AT-S70
Management Software User's Guide.
For port pinouts when the port is operating at 10 or 100 Mbps in the MDI
configuration, refer to Table 20 on page 89.
For port pinouts when the port is operating at 10 or 100 Mbps in the MDI-X
configuration, refer to Table 21 on page 89.
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