Alcatel-Lucent 9500 MXC, User Manual, Page: 442 / 916

Chapter 7. Node and Terminal Plug-ins
Vol. IV-7-52 Alcatel-Lucent
result or where a fixed setting is preferred:
• Auto negotiation is not 100% reliable, particularly so where the
connected equipment is using an older auto-sensing mechanism.
• Links with a duplex mismatch will operate, but will generate a large
number of errors and will slow throughput.
• Generally, for auto negotiation to work, both interfaces must be set to
auto for speed and duplex.
• Full-duplex can only be achieved if both interfaces are either set for
auto-negotiation or are manually configured to use full duplex.
• Full duplex will not operate via a hub/repeater. These are half duplex
devices.
• If auto-negotiation is enabled on only one side of the link, it will always
default to half-duplex, regardless of what the other side of the link is
forced to.
• If one side of a link is forced to full duplex and the other is set to
auto-negotiation, a duplex mismatch will occur.
• You can force a new auto-negotiation by simply unplugging a host
cable for 10 seconds.
• Most 10 Mb interfaces can run only in 10 Mb half-duplex mode.
• Most 10/100 Mb interfaces support auto-negotiation and most 10/100
Mb interfaces with RJ-45 twisted-pair can run in full-duplex mode.
• Any network connected via an AUI port (Attachment Unit Interface),
such as on an external Ethernet transceiver, can run only in 10Mb
half-duplex mode.
5.4 Mdi/MdiX
: Click to view and select auto-detect or a specified cable type.
The normal setting is Auto, where the auto negotiation protocol senses
and sets the port connection cable type to Mdi or MdiX (straight or
cross-over cable respectively). The fixed options are used where auto
negotiation fails to provide the expected result or where a fixed setting is
preferred.
5.5 Priority
: Sets the port priority. The options are high, medium high,
medium low, and low. To change, select from the priority menu. Each
port can be prioritized in this way.
• This prioritization only has relevance where two or more ports use a
common channel.