Net Optics GigaBit Media Converters User Manual

Page 11

GigaBit Media Converter

Configuration Guidelines for Link Fault Signaling (LFS)

Operation

Link Fault Signaling (LFS) circuitry provides visual indication of link

condition on both segments, as well as alerting each end host device when a

remote link (segment) is down. If either segment experiences a link failure,

the good segment port LED will remain lit. BUT, the Link idle signal going

to the next, remaining device on the GOOD segment, is instantly disabled,

turning off its Link LED. The converter detects the loss of link on one

segment and turns off the link signal to the next segment, even though the

second segment is intact .

The missing link signal alerts the end device(s) that a fault has occurred.

Either end can then establish an alternate connection path, using Spanning

Tree protocol. Once the original fault is corrected, all segment links are re-

established and the Link LEDs function in the normal manner.

All connections between the converter and end devices must be made before a

good end-to-end link can be established. A normal good link on both segments

will be indicated by both link LEDs lit.

At least one end device must provide a link signal to initiate a link across

all segments. If one link segment is broken, the associated link LED will no

longer be lit. The good (unbroken) segment’s link LED will remain lit and the

Link Idle signal to the next segment will turn off.

When the converter loses a link signal from either of the two devices

attached to it, the converter turns off (ceases to forward) the port link signal

to the NEXT segment (device). When the fault is corrected, all links will be

automatically re-established.