Cisco NCS 1010 and NCS 1020 Datapath Configuration Guide, IOS XR Releases 25.x.x

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Cisco NCS 1010 and NCS 1020 Datapath Configuration Guide, IOS XR Releases 25.x.x

OSC controllers

Updated: June 17, 2026

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This section explains how OSC controllers provide communication, monitoring, and management functions within optical networks.

The Optical Service Channel (OSC) controller is used to represent the optical capabilities, configuration, and monitoring of the OSC laser. The corresponding Gigabit Ethernet interface is the child interface that represents Ethernet capabilities, configuration, and monitoring.

OSC provides a communication channel for traffic coming from a UDC port. OSC serves as a channel probe to check fiber continuity between two nodes. OSC provides remote node management functionality. OSC is generated and terminated on each line side. OSC-C operates at a frequency of 198.50 THz and OSC-L operates at a frequency of 184.450 THz.

Nodes with NCS1K-OLT-R-C or NCS1K-OLT-C, NCS1K-OLT-L cards have one OSC controller. To view the status of the OSC controller, use this command:

RP/0/RP0/CPU0:ios#show controller description

This output highlights the status of the OSC controller for the NCS1K-OLT-R-C or NCS1K-OLT-C, NCS1K-OLT-L or NCS1K-ILA-L cards.

Tue Apr 12 17:17:51.306 UTC

Interface                   Status          Description
--------------------------------------------------------------------------------
Osc0/0/0/0                  up
Ots0/0/0/0                  up
Ots0/0/0/1                  up
Ots0/0/0/2                  up
 .
 .
 output snipped
 .
 .
Ots0/0/0/31                 up
Ots0/0/0/32                 up
Ots0/0/0/33                 up

Nodes with NCS1K-ILA-2R-C, NCS1K-ILA-R-C, NCS1K-ILA-L or NCS1K-ILA-C card have two OSC controllers. To view the OSC controllers, use this command:

RP/0/RP0/CPU0:ios#show controllers description

This output highlights the status of the OSC controller for the NCS1K-ILA-2R-C, NCS1K-ILA-R-C , NCS1K-ILA-L or NCS1K-ILA-C card.

Tue Apr 12 17:20:20.667 UTC

Interface                   Status          Description
--------------------------------------------------------------------------------
Osc0/0/0/0                  up
Osc0/0/0/2                  up
Ots0/0/0/0                  up
Ots0/0/0/1                  up
Ots0/0/0/2                  up
Ots0/0/0/3                  up

To view the parameters of the LINE 0 OSC controller, use this command:

RP/0/RP0/CPU0:ios#show controllers osc 0/0/0/0

This output shows the parameters of the LINE 0 OSC controller.

Wed Mar 23 06:04:18.565 UTC

 Controller State: Down

 Transport Admin State: In Service

 Laser State: Off

         Alarm Status:
         -------------
         Detected Alarms:
                 RX-LOS-P

         Alarm Statistics:
         -----------------
         RX-LOS-P = 369
         TX-POWER-FAIL-LOW = 0

         Parameter Statistics:
         ---------------------
         Total TX Power = -50.00 dBm
         Total RX Power = -50.00 dBm



         Configured Parameters:
         -------------

Configure OSC Controllers

There are multiple parameters for the OSC controllers. You can configure the parameters that are required for the different configuration for an OSC controller on an ILA or OLT node by using these commands in the configuration mode:

  • transmit-power value

  • sec-admin-state {normal | maintenance}

  • tx-low-threshold

  • shutdown

Examples

In this example, the transmit-power is set to 2 dBm. The OSC Tx power can be changed by configuring the OSC transmit power attribute. This attribute internally regulates the OSC Tx VOA.

Note

The OSC controller commands do not support decimal inputs. The OSC controller commands consider the inputs to one decimal place for the parameter values. In this example, the transmit-power parameter is provided as 20 to configure the transmit-power parameter to 2 dBm.

RP/0/RP0/CPU0:ios(config)#controller osc 0/0/0/0 transmit-power 20
Fri May 13 11:26:53.445 UTC
WARNING! Changing TX power can impact traffic
RP/0/RP0/CPU0:ios(config)#commit
Fri May 13 11:26:55.127 UTC
RP/0/RP0/CPU0:ios(config)#end

To view the parameters of the OSC controller, use this command:

RP/0/RP0/CPU0:ios#show controllers osc 0/0/0/0

This output shows the parameters of the OSC controller.

Fri May 13 11:26:59.542 UTC

Controller State: Up

Transport Admin State: In Service

Laser State: On

Alarm Status:
-------------
Detected Alarms: None


Alarm Statistics:
-----------------
RX-LOS-P = 0
TX-POWER-FAIL-LOW = 0

Parameter Statistics:
---------------------
Total TX Power = 1.89 dBm
Total RX Power = -17.30 dBm



Configured Parameters:
-------------

In this example, the sec-admin-state is set to maintenance.

RP/0/RP0/CPU0:ios#config
RP/0/RP0/CPU0:ios(config)#controller osc 0/0/0/0 sec-admin-state maintenance
RP/0/RP0/CPU0:ios(config)#commit
RP/0/RP0/CPU0:ios(config)#end

To view the parameters of the OSC controller, use this command:

RP/0/RP0/CPU0:ios#show controllers osc 0/0/0/0

This output highlights the Transport Admin State of the OSC controller that is set to Maintenance.

Fri Apr 22 15:55:36.324 UTC

 Controller State: Up

 Transport Admin State: Maintenance

 Laser State: On

         Alarm Status:
         -------------
         Detected Alarms: None


         Alarm Statistics:
         -----------------
         RX-LOS-P = 0
         TX-POWER-FAIL-LOW = 0

         Parameter Statistics:
         ---------------------
         Total TX Power = -10.00 dBm
         Total RX Power = -30.00 dBm



         Configured Parameters:
         -------------

In this example, the OSC controller is shut down.

P/0/RP0/CPU0:ios#config
RP/0/RP0/CPU0:ios(config)#controller osc 0/0/0/0 shutdown
RP/0/RP0/CPU0:ios(config)#commit
RP/0/RP0/CPU0:ios(config)#end

To view the parameters of the OSC controller that is shut down, use this command:

RP/0/RP0/CPU0:ios#show controllers osc 0/0/0/0

This output highlights the Controller State, Transport Admin State, and Laser State of the OSC controller that is shut down.

Tue Apr 12 17:33:12.998 UTC

 Controller State: Administratively Down

 Transport Admin State: Out Of Service

 Laser State: Off

         Alarm Status:
         -------------
         Detected Alarms: None


         Alarm Statistics:
         -----------------
         RX-LOS-P = 0
         TX-POWER-FAIL-LOW = 0

         Parameter Statistics:
         ---------------------
         Total TX Power = -50.00 dBm 
         Total RX Power = -30.00 dBm



         Configured Parameters:
         -------------

View the Gigabit Ethernet interfaces

Display operational and configuration details for a Gigabit Ethernet interface.

A Gigabit Ethernet interface represents the packet layer of an OSC channel and is used for high-speed data transmission between optical nodes.

Table 1. Feature History

Feature Name

Release Information

Feature Description

1G Speed support on OSC Gigabit Ethernet

 Cisco IOS XR Release 25.4.1

The Gigabit Ethernet interface on the OSC now supports data rates up to 1 Gbps, in addition to the existing 100 Mbps.

This enhancement allows you to configure the interface speed to 1 Gbps, enabling the use of UDC ports to extend your Data Communication Network (DCN) for monitoring remote NCS 1010 and NCS 1020 sites.

To enable 1 Gbps throughput for the Gigabit Ethernet interface, use the command interface gigabitEthernet R/S/I/P and set the speed to 1000.

IP based Packet forwarding Throughput on OSC Gigabit is maximum 200Mbps and UDC Traffic Over OSC Gigabit is maximun upto 880Mbps.

For speed configuration options:

  • The 100 Mbps speed can be configured using the command

    speed 100.

  • If the speed configuration is removed using the command no speed, the default speed will revert to 100 Mbps.

  • Configuring a 10 Mbps speed is not supported and will result in failure.

Before you begin

Ensure that the node is operational at the intended speed.

Note

Zero Touch Provisioning (ZTP) is not supported on a 1 GE interface. You must bring up the node at the default 100 Mbps speed, and then change the interface to 1GE.

Follow these steps to view a Gigabit Ethernet interface:

Procedure

1.

Run the show interfaces gigabitEthernet 0/0/0/0 command to view the parameters and status of a Gigabit Ethernet interface.

Example:


RP/0/RP0/CPU0:ios#show run int gigabitEthernet 0/0/0/0 
Fri Nov 21 16:00:55.645 IST
interface GigabitEthernet0/0/0/0
 description noshut-interface
 ipv4 address 7.1.11.1 255.255.255.0
 ipv6 enable
 lldp
  enable
 !
 speed 1000
!

RP/0/RP0/CPU0:ios#show int gigabitEthernet 0/0/0/0 
Fri Nov 21 16:01:03.275 IST
GigabitEthernet0/0/0/0 is up, line protocol is up 
  Interface state transitions: 1
  Hardware is GigabitEthernet, address is 38fd.f866.0693 (bia 38fd.f866.0693)
  Description: noshut-interface
  Internet address is 7.1.11.1/24
  MTU 1514 bytes, BW 1000000 Kbit (Max: 1000000 Kbit)
     reliability 255/255, txload 0/255, rxload 0/255
  Encapsulation ARPA,
  Full-duplex, 1000Mb/s, unknown, link type is force-up
  output flow control is off, input flow control is off
  loopback not set,
  Last link flapped 20:52:33
  ARP type ARPA, ARP timeout 04:00:00
  Last input 00:00:00, output 00:00:00
  Last clearing of "show interface" counters never
  5 minute input rate 403000 bits/sec, 45 packets/sec
  5 minute output rate 402000 bits/sec, 45 packets/sec
     73461739725 packets input, 4998891729534 bytes, Unknown total input drops
     Unknown drops for unrecognized upper-level protocol
     Received 0 broadcast packets, 48192 multicast packets
              0 runts, 0 giants, 0 throttles, 0 parity
     Unknown input errors, 0 CRC, Unknown frame, Unknown overrun, 0 ignored, 0 abort
     73461747443 packets output, 4998883259525 bytes, Unknown total output drops
     Output 2 broadcast packets, 33519 multicast packets
     Unknown output errors, Unknown underruns, 0 applique, Unknown resets
     0 output buffer failures, 0 output buffers swapped out
     0 carrier transitions
2.

Run the show ipv4 interface brief command to view the IPv4 address, status, operational state, and VRF name.

This output highlights the interface, IPv4 address (IP-Address), status, operational status of the routing protocol (Protocol), VPN routing and forwarding (VRF) instance name (Vrf-Name) of the Gigabit Ethernet interface.

Example:


Tue Apr 19 10:58:02.951 UTC
Interface                      IP-Address      Status          Protocol Vrf-Name
Loopback0                      10.3.3.11       Up              Up       default
Loopback3                      10.1.1.1        Up              Up       default
GigabitEthernet0/0/0/0         10.7.1.1        Up              Up       default
MgmtEth0/RP0/CPU0/0            10.33.0.61      Up              Up       default
PTP0/RP0/CPU0/0                unassigned      Shutdown        Down     default
MgmtEth0/RP0/CPU0/1            unassigned      Shutdown        Down     default
PTP0/RP0/CPU0/1                unassigned      Shutdown        Down     default
MgmtEth0/RP0/CPU0/2            unassigned      Shutdown        Down     default

The Gigabit Ethernet interface must be in Up state for the OSC laser to become active. When the node starts, the Gigabit Ethernet interface changes to Down state.

3.

Run the no interface gigabitEthernet command on the Gigabit Ethernet interface to bring it up.

The Gigabit Ethernet interface must be in Up state for the OSC laser to turn up. When the node comes up, the Gigabit Ethernet interface turns to Down state.

Example:


RP/0/RP0/CPU0:ios#config
RP/0/RP0/CPU0:ios(config)#interface gigabitEthernet 0/0/0/0 
RP/0/RP0/CPU0:ios(config)#no shutdown
4.

Run the no speed 1000 command to remove the speed configuration from the interface.

Example:


RP/0/RP0/CPU0:ios(config)#interface gigabitEthernet 0/0/0/0
RP/0/RP0/CPU0:ios(config)#no speed 1000
RP/0/RP0/CPU0:ios(config)#commit

You successfully display operational and configuration details of the Gigabit Ethernet interface, including speed, status, counters, and port parameters.

Best practice for downgrading from OSC 1G

Remove the 1G OSC speed configuration from OLT and ILA nodes before downgrading from Release 25.4.1 or a later version to a software version that does not support the OSC 1G feature.

  • Once you delete the OSC 1G speed configuration, the OSC port operates at 100 Mbps.

  • If you remove the 1G setting before downgrading, you do not need to reload any rack after the downgrade.

Release 25.4.1 and later versions support 1 GE OSC speed.

These tables provide key technical specifications for the OSC link speeds, including file transfer rates, UDC throughput, and management traffic performance.
Note

Speed 1000 Mbps and Speed 100 Mbps are supported. Speed 10 Mbps is not supported.

Table 2. File transfer speed through OSC link

OSC link speed

Transfer rate at first hop

Transfer rate at second hop

100 Mbps (default speed)

87 Mbps

87 Mbps

1 GE (new speed)

232 Mbps

176 Mbps
Table 3. UDC throughput with IPv4 traffic
OSC link speed UDC throughput (64 packets) UDC throughput (256 - 1000 packets) UDC throughput (1514 packets)
100 Mbps (default speed) 68 Mbps 83 Mbps 88 Mbps
1 GE (new speed) 680 Mbps 830 Mbps 880 Mbps
Table 4. Management traffic through OSC link
OSC link speed IMIX Packet size 95 Packet size 500 Packet size 1000 Packet size 1500
1000 Mbps 50 Mbps 14 Mbps 60 Mbps 150 Mbps 200 Mbps
100 Mbps 50 Mbps 14 Mbps 60 Mbps 90 Mbps 90 Mbps