Overview of Automatic Power Control
On a fiber, the power level may vary between channels. Over long distances and multiple amplifications, these differences in power levels can result in deterioration of the quality of some channels. Automatic Power Control (APC) corrects the power level differences and ensures that power for different channels is according to the target power profile for the spectrum. APC compensates for the degradation of the network over time. APC is enabled if automatic link bring up is enabled.
APC is a network-level feature that is distributed among different nodes. An APC domain is a set of nodes that is controlled by the same instance of APC at the network level. An APC domain identifies a portion of the network that can be independently regulated. The source OLT node acts as the APC Manager or Domain Manager for all the nodes in the path. The subsequent nodes in the path act as APC agent nodes. The manager node enables APC on agent nodes, monitors DISCREPANCY and initiates regulation if correction is required. To avoid large power fluctuations, APC adjusts power levels incrementally. APC performs power correction in steps of +/-0.8dB. This is applied to each iteration until the optimal power level is reached.
APC is direction-specific. You can enable APC for each direction at the transmitting OLT node. The source node enables and controls different parameters in all ILA nodes on the path and the far-end OLT ingress EDFA.
The following table lists the parameters that APC configures and controls in different nodes.
| Node | Parameters |
|---|---|
|
Transmitting OLT |
EDFA Gain EDFA Tilt VOA Attenuation WSS Attenuation |
| ILA |
EDFA Gain EDFA Tilt VOA Attenuation DGE Attenuation |
| Receiving OLT |
EDFA Gain EDFA Tilt WSS Attenuation |
When you enable APC, APC controls these parameters. APC overrides any manual configuration. When you disable APC, user configuration is applied.
APC divides the C band spectrum into 32 equal parts. APC uses 33 frequencies across the C band to divide the band. We call these 33 frequencies, setpoints. Each setpoint is 150 GHz apart from the adjacent setpoints. You can configure a power profile across the spectrum using these setpoints. You can configure the target PSD for each OLT and ILA node on a link.
APC applies amplification and attenuation as required at channel level and composite signal level to ensure that the channels are at the target power level. You can configure the target power spectral densities for 33 points across the band. If you enable link tuner, link tuner sets the target PSDs for APC on all nodes in the path.
APC performs the following functions:
-
APC monitors the current PSD against the target PSD for each channel (ASE and user channel) and changes the amplifier parameters including VOA, WSS, and DGE to achieve the target PSD.
-
APC detects optical network changes on the path and alters the amplifier parameters on the nearest nodes to compensate for the changes. APC performs these alterations in multiple steps.
-
APC collects measurements from other link nodes at the transmitting OLT to precisely locate optical network changes.
From Cisco IOS XR Release 7.9.1, NCS 1010 supports C+L band networks. Before Cisco IOS XR Release 7.9.1, APC did not start regulating the power levels in a link until the full topology was discovered by OSPF. From Cisco IOS XR Release 7.9.1, APC regulation begins as soon as it discovers any part of the topology. At a transmitting OLT, it starts power correction at the OLT and subsequent ILA nodes even if the complete OLT-OLT link has not been discovered. When APC detects a partial topology, the NCS 1010 raises the PARTIAL-TOPOLOGY alarm, and after the regulation is complete APC moves to BLOCKED state.
 Note |
|
View APC Status and Information
Use the show olc apc command to view APC status.
The following sample is an output of show olc apc.
RP/0/RP0/CPU0:OLT1#show olc apc
Controller : Ots0/0/0/0
APC Status : WORKING
Node RID : 10.1.1.1
Internal State : IDLE
Node RID : 10.99.1.2
Internal State : IDLE
Node RID : 10.99.2.2
Internal State : IDLE
Node RID : 10.99.4.1
Internal State : IDLE
Node RID : 10.1.1.5
Internal State : DISCREPANCY
APC Status is the status of APC in the complete path. The following table lists and describes the APC Statuses.
| APC Status | Description |
| BLOCKED |
APC moves to BLOCKED state if:
|
| PAUSED |
APC is paused using the apc-pause command. |
| IDLE | APC regulation has been completed successfully. All the channels in the network have achieved the target PSD provided by Link-tuner or configured by user |
| WORKING | APC detected a DISCREPANCY between current and target PSD. APC regulation is in progress to converge the power to target PSD. |
| DISABLED | APC is disabled. |
|
PARTIAL-TOPOLOGY NODE-BLOCKED |
APC has limited visibility. APC manager does not have visibility to the full OLT-OLT topology. APC manager tries to correct the power levels on the agent nodes that are reachable and after the regulation is complete, APC moves to BLOCKED state. |
Internal State is the state of APC on each individual node. The following table lists and describes the internal states.
| APC Internal State | Description |
| DISCREPANCY | The APC manager flags an agent node which needs correction when there is a discrepancy between target PSD and current PSD. This state is temporary and lasts until APC starts power correction and goes into CORRECTING state. |
| CORRECTING | APC correction is in progress on the node |
| OOR | APC-OUT-OF-RANGE condition is raised on an agent node when APC fails to regulate and achieve the target PSD power level because
the requested gain or attenuation setpoint cannot be set due to one of the following conditions:
|
| IDLE | APC regulation has been completed successfully. All the channels in the network have achieved the target PSD provided by Link-tuner or configured by user |
|
BLOCKED |
APC is unable to perform for the following reasons:
|
The following sample is an output of show olc apc command when OSRI has shut down an amplifier in the link.
RP/0/RP0/CPU0:ios#sh olc apc
Thu Jul 7 13:21:05.807 UTC
Controller : Ots0/0/0/0
APC Status : BLOCKED
Node RID : 10.1.1.1
Internal State : IDLE
Node RID : 10.1.1.2
Internal State : BLOCKED
Blocked Reason : [ AMPLI-SHUT ]
Node RID : 10.1.1.3
Internal State : DISCREPANCY
Node RID : 10.1.1.4
Internal State : DISCREPANCY
Node RID : 10.1.1.5
Internal State : DISCREPANCYThe following sample is an output of show olc apc command when APC is disabled locally on a node.
RP/0/RP0/CPU0:ios#sh olc apc
Thu Jul 7 13:22:44.145 UTC
Controller : Ots0/0/0/0
APC Status : BLOCKED
Node RID : 10.1.1.1
Internal State : IDLE
Node RID : 10.1.1.2
Internal State : BLOCKED
Blocked Reason : [ USER-DISABLED ]
Node RID : 10.1.1.3
Internal State : DISCREPANCY
Node RID : 10.1.1.4
Internal State : DISCREPANCY
Node RID : 10.1.1.5
Internal State : DISCREPANCYThe following sample is an output of show olc apc command when Gain Estimation is in progress on a node.
RP/0/RP0/CPU0:ios#sh olc apc
Tue Jun 7 11:43:10.801 UTC
Controller : Ots0/0/0/0
APC Status : BLOCKED
Node RID : 10.1.1.1
Internal State : DISCREPANCY
Node RID : 10.1.1.2
Internal State : DISCREPANCY
Node RID : 10.1.1.3
Internal State : BLOCKED
Blocked Reason : [ GAIN-ESTIMATION-IN-PROGRESS ]The following sample is an output of show olc apc command when amplifier auto power reduction is enabled on a node.
RP/0/RP0/CPU0:ios#sh olc apc
Thu Jul 7 13:21:49.530 UTC
Controller : Ots0/0/0/0
APC Status : BLOCKED
Node RID : 10.1.1.1
Internal State : IDLE
Node RID : 10.1.1.2
Internal State : BLOCKED
Blocked Reason : [ AMPLI-APR-ENABLED ]
Node RID : 10.1.1.3
Internal State : DISCREPANCY
Node RID : 10.1.1.4
Internal State : DISCREPANCY
Node RID : 10.1.1.5
Internal State : DISCREPANCY
The following sample is an output of show olc apc command when band failure has occurred and the APC manager has visibility only to a partial topology.
RP/0/RP0/CPU0:ios#show olc apc
Wed Jan 18 12:21:28.195 UTC
Controller : Ots0/0/0/0
APC Status : BLOCKED
Blocked Reason : [ PARTIAL-TOPOLOGY NODE-BLOCKED ]
Node RID : 10.1.1.1
Internal State : IDLE
Node RID : 10.1.1.2
Internal State : BLOCKED
Blocked Reason : [ BAND-FAILURE ]
You can view the local status of APC on each node using the show olc apc-local command. This command shows if APC is enabled or disabled on the node.
The following sample is an output of show olc apc-local command.
RP/0/RP0/CPU0:ios#show olc apc-local
Mon Apr 11 06:59:14.679 UTC
Controller : Ots0/0/0/0
TX Status : ENABLED
RX Status : ENABLED
You can view the target PSDs configured for all setpoints using the show olc apc-local target-psd-profile command. The output shows the source of the PSD configuration also. The target PSD source can be Link Tuner or Configuration.
The following sample is an output of show olc apc-local target-psd-profile command on a C band node..
RP/0/RP0/CPU0:ios#show olc apc-local target-psd-profile
Tue Apr 26 10:19:24.910 UTC
Controller : Ots0/0/0/0
Target PSD source : Configuration
-------------------------------------------------------------------------------
Setpoint Frequency Target PSD
(THz) (dBm/12.5 GHz)
-------------------------------------------------------------------------------
01 191.337494 15.0
02 191.488678 15.0
03 191.639847 -4.1
04 191.791016 -4.1
05 191.942184 -4.1
06 192.093353 -4.1
07 192.244537 -4.1
08 192.395706 -4.1
09 192.546875 -4.1
10 192.698044 -4.1
11 192.849213 -4.1
12 193.000397 -4.1
13 193.151566 -4.1
14 193.302734 -4.1
15 193.453903 -4.1
16 193.605072 -4.1
17 193.756256 -4.1
18 193.907425 -4.1
19 194.058594 -4.1
20 194.209763 -4.1
21 194.360931 -4.1
22 194.512115 -4.1
23 194.663284 -4.1
24 194.814453 -4.1
25 194.965622 -4.1
26 195.116791 -4.1
27 195.267975 -4.1
28 195.419144 -4.1
29 195.570312 -4.1
30 195.721481 -4.1
31 195.872650 -4.1
32 196.023834 -4.1
33 196.175003 -4.1
The following sample is an output of show olc apc-local target-psd-profile command on an L band node.
RP/0/RP0/CPU0:ios#sh olc apc-local target-psd-profile
Wed Jan 18 12:12:02.236 UTC
Controller : Ots0/0/0/0
Target PSD source : Configuration
-------------------------------------------------------------------------------
Setpoint Frequency Target PSD
(THz) (dBm/12.5 GHz)
-------------------------------------------------------------------------------
01 186.050000 -6.4
02 186.201000 -6.3
03 186.352000 -6.2
04 186.503000 -6.2
05 186.654000 -6.1
06 186.805000 -6.1
07 186.956000 -6.0
08 187.107000 -6.0
09 187.258000 -5.9
10 187.409000 -5.9
11 187.560000 -5.9
12 187.711000 -5.8
13 187.862000 -5.7
14 188.013000 -5.7
15 188.164000 -5.6
16 188.315000 -5.5
17 188.466000 -5.5
18 188.617000 -5.4
19 188.768000 -5.4
20 188.919000 -5.3
21 189.070000 -5.2
22 189.221000 -5.2
23 189.372000 -5.1
24 189.523000 -5.1
25 189.674000 -5.0
26 189.825000 -5.0
27 189.976000 -4.9
28 190.127000 -4.9
29 190.278000 -4.8
30 190.429000 -4.7
31 190.580000 -4.7
32 190.731000 -4.6
33 190.882000 -4.6
You can view the detailed information about APC on each node using the show olc apc-local regulation-info command. This command provides the following information:
-
Controller
-
APC Domain Manager
-
Internal Status
-
Minimum PSD
-
Last correction timestamp
-
Gain range
-
Amplifier and attenuation parameters: Configured and current values and available ranges
-
Detailed information on the channels
The following details are available:
-
Center frequency of each channel
-
Channel width
-
Channel ID
-
Channel Source (ASE or user channel)
-
Slice number of the center frequency of the channel in the WSS
-
PSD of the channel at the input of the amplifier
-
Target PSD for the channel
-
Current PSD of the channel
-
Discrepancy between current and target PSD
-
The configured attenuation on the WSS (OLT) or DGE (ILA) for the channel
-
You can view the APC information for only the Tx or Rx direction using the tx|rx keyword with the show olc apc-local regulation-info controller ots R/S/I/P command.
The following sample is an output of show olc apc-local regulation-info command.
RP/0/RP0/CPU0:ios#show olc apc-local regulation-info controller ots 0/0/0/0 tx
Wed Jul 6 05:01:45.177 UTC
Controller : Ots0/0/0/0
Domain Manager : 10.1.1.1
Internal Status : OOR
Direction : TX
PSD Minumum : -24.0 (dBm/12.5 GHz)
Gain Range : Normal
Last Correction : 2022-07-06 05:01:28
Device Parameters Min Max Configuration Operational
===========================================================================
Egress Ampli Gain (dB) :15.4 29.4 19.5 19.5
Egress Ampli Tilt (dB) :-5.0 3.1 -2.2 -2.2
TX Ampli Power (dBm) : - 22.4 - 21.4
TX VOA Attenuation (dB) :0.0 20.0 0.0 0.0
Egress WSS/DGE Attenuation (dB) :0.0 25.0 - -
Channel Center Channel Channel Channel Spectrum Ampli-Input Target Current Discrepancy Channel Slice
Frequency Width ID Source Slice Num PSD PSD PSD Attn Config
(THz) (GHz) (dBm/12.5 GHz)(dBm/12.5 GHz)(dBm/12.5 GHz) (dB) (dB)
====================================================================================================================
191.375000 75.00 1 OCh 13 -23.2 -4.6 -4.9 0.2 7.1
191.449997 75.00 - ASE 37 -23.0 -4.6 -4.7 0.1 9.2
191.524994 75.00 - ASE 61 -23.1 -4.6 -4.7 0.1 9.3
191.600006 75.00 4 OCh 85 -23.1 -4.5 -4.7 0.1 8.0
191.675003 75.00 - ASE 109 -23.0 -4.5 -4.5 0.0 9.1
191.750000 75.00 6 OCh 133 -23.0 -4.4 -4.6 0.1 8.0
191.824997 75.00 - ASE 157 -23.1 -4.4 -4.6 0.1 9.3
191.899994 75.00 8 OCh 181 -23.0 -4.4 -4.4 0.0 8.0
191.975006 75.00 - ASE 205 -23.0 -4.3 -4.5 0.1 9.1
192.050003 75.00 10 OCh 229 -23.0 -4.3 -4.5 0.1 8.2
192.125000 75.00 - ASE 253 -22.9 -4.3 -4.3 0.0 9.0
192.199997 75.00 12 OCh 277 -22.8 -4.2 -4.3 0.0 8.3
192.274994 75.00 - ASE 301 -22.9 -4.2 -4.4 0.1 9.0
192.350006 75.00 14 OCh 325 -22.6 -4.2 -4.2 0.0 8.3
192.425003 75.00 - ASE 349 -22.8 -4.2 -4.3 0.1 8.7
192.500000 75.00 16 OCh 373 -22.4 -4.1 -3.9 -0.2 8.1
192.574997 75.00 - ASE 397 -22.7 -4.1 -4.2 0.1 8.6
192.649994 75.00 18 OCh 421 -22.6 -4.1 -4.2 0.1 8.1
192.725006 75.00 - ASE 445 -22.7 -4.0 -4.2 0.1 8.6
192.800003 75.00 20 OCh 469 -22.7 -4.0 -4.1 0.1 7.9
192.875000 75.00 - ASE 493 -22.6 -4.0 -4.0 0.0 8.4
192.949997 75.00 22 OCh 517 -22.6 -3.9 -4.1 0.1 7.6
193.024994 75.00 - ASE 541 -22.5 -3.9 -4.0 0.1 8.2
193.100006 75.00 24 OCh 565 -22.7 -3.8 -4.0 0.1 7.5
193.175003 75.00 - ASE 589 -22.7 -3.8 -4.0 0.1 8.2
193.250000 75.00 26 OCh 613 -22.5 -3.8 -3.9 0.1 7.2
193.324997 75.00 - ASE 637 -22.6 -3.8 -4.0 0.2 8.1
193.399994 75.00 28 OCh 661 -22.7 -3.7 -3.9 0.1 7.2
193.475006 75.00 - ASE 685 -22.5 -3.7 -3.8 0.1 8.0
193.550003 75.00 30 OCh 709 -22.7 -3.7 -3.8 0.1 7.0
193.625000 75.00 - ASE 733 -22.7 -3.6 -3.8 0.1 8.1
193.699997 75.00 32 OCh 757 -22.7 -3.6 -3.7 0.1 6.7
193.774994 75.00 - ASE 781 -22.7 -3.5 -3.7 0.1 8.2
193.850006 75.00 34 OCh 805 -22.7 -3.5 -3.7 0.1 6.6
193.925003 75.00 - ASE 829 -22.7 -3.5 -3.6 0.1 8.1
194.000000 75.00 36 OCh 853 -22.8 -3.5 -3.7 0.2 6.6
194.074997 75.00 - ASE 877 -22.8 -3.4 -3.6 0.1 8.3
194.149994 75.00 38 OCh 901 -22.7 -3.4 -3.5 0.1 10.9
194.225006 75.00 - ASE 925 -22.8 -3.3 -3.5 0.1 8.2
194.300003 75.00 40 OCh 949 -22.9 -3.3 -3.5 0.1 7.1
194.375000 75.00 - ASE 973 -22.8 -3.3 -3.4 0.1 8.4
194.449997 75.00 42 OCh 997 -22.9 -3.2 -3.5 0.2 7.3
194.524994 75.00 - ASE 1021 -22.9 -3.2 -3.4 0.1 8.4
194.600006 75.00 44 OCh 1045 -22.8 -3.2 -3.3 0.1 7.2
194.675003 75.00 - ASE 1069 -22.8 -3.2 -3.3 0.1 8.4
194.750000 75.00 46 OCh 1093 -22.9 -3.1 -3.4 0.2 7.3
194.824997 75.00 - ASE 1117 -22.8 -3.1 -3.2 0.1 8.2
194.899994 75.00 48 OCh 1141 -22.8 -3.0 -3.3 0.2 6.9
194.975006 75.00 - ASE 1165 -22.9 -3.0 -3.2 0.1 8.3
195.050003 75.00 50 OCh 1189 -22.8 -3.0 -3.1 0.1 6.6
195.125000 75.00 - ASE 1213 -22.9 -3.0 -3.1 0.1 8.3
195.199997 75.00 52 OCh 1237 -22.9 -2.9 -3.1 0.1 6.3
195.274994 75.00 - ASE 1261 -23.0 -2.9 -3.0 0.1 8.1
195.350006 75.00 54 OCh 1285 -23.1 -2.8 -3.0 0.1 6.4
195.425003 75.00 - ASE 1309 -23.2 -2.8 -3.0 0.1 8.3
195.500000 75.00 56 OCh 1333 -23.1 -2.8 -2.9 0.1 6.2
195.574997 75.00 - ASE 1357 -23.4 -2.8 -3.0 0.2 8.2
195.649994 75.00 58 OCh 1381 -23.4 -2.7 -2.9 0.1 6.4
195.725006 75.00 - ASE 1405 -23.4 -2.7 -2.8 0.1 8.5
195.800003 75.00 60 OCh 1429 -23.6 -2.7 -2.8 0.1 6.6
195.875000 75.00 - ASE 1453 -23.7 -2.6 -2.9 0.2 8.7
195.949997 75.00 62 OCh 1477 -23.7 -2.6 -2.8 0.2 6.9
196.024994 75.00 - ASE 1501 -23.6 -2.5 -2.7 0.1 9.0
196.100006 75.00 64 OCh 1525 -23.7 -2.5 -2.7 0.1 7.1
ASE - Noise Loaded Channel
OCh - Optical Channel
Note |
|
Configure APC
If you enable link tuner, the link tuner sets the target PSDs for APC on all nodes in the path.
You can configure the target power spectral densities for 33 points across the band. The 33 PSD values divide the entire spectrum into 150-GHz steps. APC uses the corresponding PSD value if the channel frequency corresponds to a configured point. If the central frequency is not on a configured position, APC computes the target PSD for a channel by extrapolating from the two adjacent steps.
Use the following commands to set the target PSDs for single-band for each node on a C-band network.
configure
optical-line-control
controller ots Rack/Slot/Instance/Port
psd <1-33> value
commit
end
The following is a sample configuration that sets the psd to 15 dBm/12.5 GHz for the setpoints 1 and 2.
RP/0/RP0/CPU0:ios#configure
RP/0/RP0/CPU0:ios(config)#optical-line-control
RP/0/RP0/CPU0:ios(config-olc)#controller ots 0/0/0/0
RP/0/RP0/CPU0:ios(config-olc-ots)#psd 1 150
RP/0/RP0/CPU0:ios(config-olc-ots)#psd 2 150
RP/0/RP0/CPU0:ios(config-olc-ots)#commit
RP/0/RP0/CPU0:ios(config-olc-ots)#end
Use the following commands to set the target PSDs for dual-band for each node on a C+L band network.
configure
optical-line-control
controller ots Rack/Slot/Instance/Port
dual-band-psd <1-33> value
commit
end
Example
The following is a sample configuration that sets the dual-band psd values to -50 and -49 on setpoints 1 and 2 respectively, on the 0/0/0/0 controller .
RP/0/RP0/CPU0:ios#configure
RP/0/RP0/CPU0:ios(config)#optical-line-control
RP/0/RP0/CPU0:ios(config-olc)#controller ots 0/0/0/0
RP/0/RP0/CPU0:ios(config-olc-ots)#dual-band-psd 1 -50
RP/0/RP0/CPU0:ios(config-olc-ots)#dual-band-psd 2 -49
RP/0/RP0/CPU0:ios(config-olc-ots)#commit
RP/0/RP0/CPU0:ios(config-olc-ots)#endDisable APC
To disable APC for a link, execute the following commands on the transmitting OLT node.
configure
optical-line-control
controller ots Rack/Slot/Instance/Port
apc disable
commit
end
The following is a sample configuration that disables APC.
RP/0/RP0/CPU0:ios#configure
RP/0/RP0/CPU0:ios(config)#optical-line-control
RP/0/RP0/CPU0:ios(config-olc)#controller ots 0/0/0/0
RP/0/RP0/CPU0:ios(config-olc-ots)#apc disable
RP/0/RP0/CPU0:ios(config-olc-ots)#commit
RP/0/RP0/CPU0:ios(config-olc-ots)#endImportant |
|
Enable APC
To enable APC for a link, execute the following commands on the transmitting OLT node.
configure
optical-line-control
controller ots Rack/Slot/Instance/Port
apc enable
commit
end
The following is a sample configuration that enables APC.
RP/0/RP0/CPU0:ios#configure
RP/0/RP0/CPU0:ios(config)#optical-line-control
RP/0/RP0/CPU0:ios(config-olc)#controller ots 0/0/0/0
RP/0/RP0/CPU0:ios(config-olc-ots)#apc enable
RP/0/RP0/CPU0:ios(config-olc-ots)#commit
RP/0/RP0/CPU0:ios(config-olc-ots)#endPause APC
If you want to modify the network without APC compensating for the changes, you can pause APC. Use the following commands to pause APC.
configure
optical-line-control
controller ots Rack/Slot/Instance/Port
apc-pause
commit
end
The following is a sample configuration that pauses APC.
RP/0/RP0/CPU0:ios#configure
RP/0/RP0/CPU0:ios(config)#optical-line-control
RP/0/RP0/CPU0:ios(config-olc)#controller ots 0/0/0/0
RP/0/RP0/CPU0:ios(config-olc-ots)#apc pause
RP/0/RP0/CPU0:ios(config-olc-ots)#commit
RP/0/RP0/CPU0:ios(config-olc-ots)#endNote |
|
Disable APC on an ILA Node
If you want to manually disable APC on a particular node. For example, consider a scenario where the headend OLT encounters a headless event. For any power correction required at agent nodes, APC manager is unavailable to initiate regulation. Also, you cannot perform any adjustments as APC is enabled and user-configuration of target-psd does not take effect. This command gives you an option to disable APC locally on an agent node to perform the parameter adjustments manually. Use the apc-local disable command to disable APC on an agent node.
Use the following commands to disable APC on an ILA node.
configure
optical-line-control
controller ots Rack/Slot/Instance/Port
apc-local [ RX | TX ] disable
commit
end
The following is a sample configuration that disables APC locally.
RP/0/RP0/CPU0:ios#configure
RP/0/RP0/CPU0:ios(config)#optical-line-control
RP/0/RP0/CPU0:ios(config-olc)#controller ots 0/0/0/0
RP/0/RP0/CPU0:ios(config-olc-ots)#apc-local RX disable
RP/0/RP0/CPU0:ios(config-olc-ots)#commit
RP/0/RP0/CPU0:ios(config-olc-ots)#endConfigure Target Drop PSD
Link Tuner does not set the target PSD for drop ports. The default target PSD for drop ports is -8.0 dBm/12.5 GHz. The NCS 1010 applies drop PSD configuration for channels with cross connect configurations. Use the drop-psd command to set the desired drop-psd.
Use the following commands to set the desired drop-psd.
configure
optical-line-control
controller ots Rack/Slot/Instance/Port
drop-psd value
commit
end
The following is a sample configuration that sets the target PSD at drop ports to –25 dBm/12.5 GHz.
RP/0/RP0/CPU0:ios#configure
RP/0/RP0/CPU0:ios(config)#optical-line-control
RP/0/RP0/CPU0:ios(config-olc)#controller ots 0/0/0/0
RP/0/RP0/CPU0:ios(config-olc-ots)#drop-psd -250
RP/0/RP0/CPU0:ios(config-olc-ots)#commit
Tue Apr 26 09:50:12.055 UTC
RP/0/RP0/CPU0:ios(config-olc-ots)#end
Configure Minimum PSD
If the PSD of a channel with minimum attenuation at the amplifier input on an OLT is less than the minimum PSD, APC marks the channel as failed and replaces the channel using ASE source. The default minimum PSD is –24 dBm/12.5 GHz. Use the psd-min command to set the desired minimum PSD.
Use the following commands to set the desired minimum PSD.
configure
optical-line-control
controller ots Rack/Slot/Instance/Port
psd-min value
commit
end
The following is a sample configuration that sets the minimum PSD to –25 dBm/12.5 GHz.
RP/0/RP0/CPU0:ios#configure
RP/0/RP0/CPU0:ios(config)#optical-line-control
RP/0/RP0/CPU0:ios(config-olc)#controller ots 0/0/0/0
RP/0/RP0/CPU0:ios(config-olc-ots)#psd-min -250
RP/0/RP0/CPU0:ios(config-olc-ots)#commit
Tue Apr 26 09:50:12.055 UTC
RP/0/RP0/CPU0:ios(config-olc-ots)#end
Path Loss
On a C+L band configuration, to launch correct power into the transmission fiber, optical applications need data about loss between the LINE-TX port of the L-band device to the LINE-TX port of the C-band device. This data, also known as path loss, is calculated from the following components:
-
Patch cord loss between the LINE-TX port of the L-band device to the L-Band-RX port of the C-band device.
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Insertion loss between the L-Band-RX port of the C-band device and the LINE-TX port of the C-band device.
-
Insertion loss due to the Raman modules inside the C-band device.
Use the show olc partner-band-loss command to view the Patchcord Loss and Path Loss values. The following output is a sample of the show olc partner-band-loss command executed on a C-band device.
RP/0/RP0/CPU0:P2B_DT_01#show olc partner-band-loss
Wed Feb 1 12:51:59.605 UTC
Controller : Ots0/0/0/0
Partner IP address : 10.1.1.2
Partner Controller : Ots0/0/0/0
L-LINE-TX Path Loss at C-LINE-TX : 2.3 dB
L-LINE-TX Patchcord Loss : 1.0 dB
Loss Measurement Timestamp : 2023-02-01 12:51:54
The following output is a sample of the show olc partner-band-loss command executed on an L-band device.
RP/0/RP0/CPU0:P1BL_DT_10#show olc partner-band-loss
Wed Feb 1 12:51:59.605 UTC
Controller : Ots0/0/0/0
Partner IP address : 10.1.1.3
Partner Controller : ots0/0/0/0
L-LINE-TX Path Loss at C-LINE-TX : 2.3 dB
L-LINE-TX Patchcord Loss : 1.0 dB
Loss Measurement Timestamp : 2023-02-01 12:51:54
You can view the Patchcord Loss and Path Loss values for individual controllers using the show olc partner-band-loss controller ots r/s/i/p command. The following output is a sample of the show olc partner-band-loss controller ots r/s/i/p command executed on a C-band device.
RP/0/RP0/CPU0:P2B_DT_01#show olc partner-band-loss controller Ots 0/0/0/0
Wed Feb 1 12:51:59.605 UTC
Controller : Ots0/0/0/0
Partner IP address : 10.1.1.2
Partner Controller : Ots0/0/0/0
L-LINE-TX Path Loss at C-LINE-TX : 1.9 dB
L-LINE-TX Patchcord Loss : 1.2 dB
Loss Measurement Timestamp : 2023-02-01 12:51:54The following output is a sample of the show olc partner-band-loss controller ots r/s/i/p command executed on an L-band device.
RP/0/RP0/CPU0:P1BL_DT_10#show olc partner-band-loss controller Ots 0/0/0/0
Wed Feb 1 12:51:59.605 UTC
Controller : Ots0/0/0/0
Partner IP address : 10.1.1.3
Partner Controller : Ots0/0/0/0
L-LINE-TX Path Loss at C-LINE-TX : 1.9 dB
L-LINE-TX Patchcord Loss : 1.2 dB
Loss Measurement Timestamp : 2023-02-01 12:51:54
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