363-206-285
Maintenance Description
Issue 3 June 2001
9-21
Figure 9-10 and Figure 9-11 are examples of the maintenance signals used by the
DDM-2000 OC-3 Multiplexer in STS and STS unequipped, respectively, path
switched ring applications.
Figure 9-10. Maintenance Signaling — STS Ring Application
DDM-2000
STS-Path AIS
Ring 2
Ring 1
LOS
LOF
Line AIS
DDM-2000
STS-Path AIS
Ring 2
Ring 1
STS-LOP
STS Path AIS
STS Sig Fail
DDM-2000
Ring 2
Ring 1
FERF
M
A
I
N
1
M
A
I
N
2
M
A
I
N
1
M
A
I
N
2
M
A
I
N
1
M
A
I
N
2
STS-Path Yellow
STS-Path Yellow*
STS-Path Yellow*
STS-Path Yellow
DDM-2000
STS-Path AIS
Ring 2
Ring 1
LOS
LOF
Line AIS
DDM-2000
STS-Path AIS
Ring 2
Ring 1
STS-LOP
STS Path AIS
DDM-2000
Ring 2
Ring 1
FERF
M
A
I
N
1
M
A
I
N
2
M
A
I
N
1
M
A
I
N
2
M
A
I
N
1
M
A
I
N
2
STS-Path Yellow
DS3
DS3
DS3
DS3 AIS*
DS3 AIS*
STS-Path AIS*
STS-Path AIS*
STS-Path Yellow
§
EC-1
STS-Path Yellow
DS3
§
on whether the STS-1 path is a drop or pass-through connection.
selected from the failed ring (Ring 1).
STS-Path Yellow, STS-Path AIS and DS3 AIS are only sent on STS-1 paths
STS-Path Yellow*
FERF
STS-Path Yellow*
FERF
§
STS-Path AIS is sent on pass-through or continue paths only.
STS-Path Yellow appears on pass-through or continue paths only.
For drop and continue applications, the STS-Path Yellow is passed
to both the EC-1/OC-3 (drop) and the OC-3 (ring) interfaces.
*
STS Unequipped
STS-Path AIS not sent for STS Unequipped.
STS-Path Yellow is passed to the EC-1/OC-3 or OC-3 interface depending
STS Unequipped
** N is 1 or 3
OC-N** OC-N** OC-N** OC-N**
OC-N** OC-N** OC-N** OC-N**
OC-N**OC-N**OC-N**OC-N**
EC-1/OC-N**
EC-1/OC-N**
EC-1/OC-N**