Allied Telesis AT-MCF2012LC/1 - Manual (Page 58)

Chapter 3: Troubleshooting
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ˆ If one or both of the networking devices are using a
spanning tree protocol, use their management firmware
to determine the status of the port connected to the
media converter channel. The port may have been
placed in the standby mode by the switch if it
represented a redundant path.
Problem 6: Two networking devices are forwarding traffic
through a channel of the media converter module, but
performance is slow.
Solution: Try the following:
ˆ There might be a duplex mode mismatch between the
twisted pair port in the channel and the networking
device connected to the port. As explained in “Twisted
Pair Ports” on page 20, a duplex mode mismatch occurs
when a twisted pair port using Auto-Negotiation is
connected to a device with a fixed duplex mode of full
duplex. If this is the cause of the problem, you must
adjust the duplex mode of the port on the networking
device or the twisted pair port on the media converter so
that both ports are using the same duplex mode.
ˆ The two networking devices are operating in different
duplex modes. As explained in “Guidelines to Using the
Media Converter Module” on page 38, a channel
performs best when its two networking devices and its
two ports all use the same duplex mode.
ˆ There could be an intermittent problem with one of the
networking devices connected to a port of the channel
or with a cable. To determine whether this might be the
problem, set the channel to the Link Test mode and
observe the Link LEDs of the ports. If one of the Link
LEDs periodically blinks, it could mean that the link is
intermittent. See Problem 7 for suggestions on how to
resolve this issue.
Problem 7: A channel is operating in the Link Test mode
and the Link LED of a port is blinking.
Solution: This could indicate that the link between the port
and the networking device is intermittent. There might be a
problem with the cable or the networking device connected
to the port. Try connecting another networking device with a
different cable to the same port on the media converter
module. If the Link LED remains steady on, then the
problem is indeed with the original cable or the networking
device.