Allied Telesis AT-S65 - Manual (Page 79)

AT-S65 Management Software User’s Guide
79
Missing Link
Disabled Modes
To prevent a link from shutting down when a failure occurs somewhere in
the signal path, use one of the missing link disabled modes.
In the first missing link mode (#2) shown in Figure 36, in case C, when
there is no optical signal received on the line side, the port (SFP) side
output is activated and the port (SFP) side input is looped back to the SFP
output. As soon as an optical signal reaches the line side, the line card
reconfigures itself to pass-through operation (case B in Figure 36).
Figure 36. Mode 2: Missing Link Disabled for Port Side and Enabled for
Line Side
CWDM
Transciever
SFP
Line
Side
Port
Side
CWDM
Transciever
SFP
Line
Side
Port
Side
CWDM
Transciever
SFP
Line
Side
Port
Side
CWDM
Transciever
SFP
Line
Side
Port
Side
X X X X
X X
X X
X
X
Legend
No optical signal
Optical signal present
Case B:
Port side: optical
signal received
Line side: optical
signal received Case C:
Port side: optical signal
received
Line side: no optical
signal received Case D:
Port side: no optical
signal received
Line side: no optical
signal received Case A:
Port side: no optical
signal received
Line side: optical signal
received