User guide

14 User Guide
Link Loss Indications
The following examples show the status of the LK LED under various link
conditions and describe when unframed all ones (AIS for E3 only) are gener-
ated. (Loopback is disabled in these examples.)
Normal
The diagram below shows a typical configuration with good link status.
Remote
Device
Local
Device
Local T3/E3
Line Card
Remote T3/E3
Line Card
green LED
unlit LED
Coax CoaxFiber
LK
LK
LK
LK
Input Coaxial Link Loss
Loss of the copper input disables the BNC port’s LK LED. It also forces the T3/
E3 card to generate unframed all ones (AIS for E3 only), which are transmitted
out its fiber port. For example, if the local card’s inbound coaxial cable breaks, it
will transmit all ones to the remote T3/E3 card via the fiber cable. The remote
card then carries the pattern forward via its coaxial cable to the remote device.
Remote
Device
Local
Device
Local T3/E3
Line Card
Remote T3/E3
Line Card
green LED
unlit LED
Coax CoaxFiber
LK
LK
LK
LK
All Ones
All Ones
All Ones carried forward
Input Fiber Link Loss
Loss of the fiber input is indicated by the fiber port’s unlit LK LED. When the
fiber input is lost, an all-ones pattern is transmitted from the coaxial port, as
shown in the illustration below.
Remote
Device
Local
Device
Local T3/E3
Line Card
Remote T3/E3
Line Card
green LED
unlit LED
Coax CoaxFiber
LK
LK
LK
LK
All Ones