# Configuration Tasks

When configuring an unchannelized SONET/SDH interface, you first configure ATM or POS on the interface. For details on configuring POS and ATM, see Configuring ATM and Configuring Packet over SONET in JunosE Link Layer Configuration Guide.

- On an OCx/STMx/DS3-ATM line module with an OC3-4 or OC12 I/O module, you can configure only ATM interfaces.
- On an OCx/STMx POS line module with an OC3-4 or OC12 I/O module, you can configure only POS interfaces.
- On an OC48 line module with an OC48 FRAME I/O module, you can configure only POS interfaces.
- On an OC3/STM1 GE/FE line module with an OC3-2 GE APS I/O module, you can configure only ATM interfaces on ports 0 and 1.
- On an ES2 4G LM with an ES2-S1 OC12-2 STM4 POS IOA or an ES2-S1 OC48 STM16 POS IOA, you can configure only POS interfaces.
- On an ES2 4G LM with an ES2-S1 OC3-8 STM1 ATM IOA or an ES2-S1 OC12-2 STM4 ATM IOA, you can configure only ATM interfaces.

## Configuring the SONET/SDH Layers

When you configure ATM or POS on an interface, you automatically configure default settings at the SONET/SDH layer. To modify the default settings:

1. Select an interface on which you want to configure SONET or SDH.
2. Specify the type of interface: SONET or SDH.
3. Specify a clock source for the interface.
4. (Optional) Assign a text description or an alias to the interface.
5. Disable processing of SNMP link status information for the section and line layers of the interface.
6. Enable processing of SNMP link status information for the path layer of the interface.
7. (Not recommended) Overwrite the automatic setting for the path signal label (C2) byte.
8. Configure the router to use remote defect indications (RDIs) at the path layer to determine the operational status of a path.
9. (MPLS fast reroute over SONET/SDH interfaces) Specify the time that the router waits to set an alarm when the router records a defect at the path layer.
10. (MPLS fast reroute over SONET/SDH interfaces) Specify the time that the router waits to set an alarm when the router records a defect at the line or section layer.
11. Shut down (disable) an interface.

clock source

- Use to configure the transmit clock source for the interface.
- In most cases, accept the default option, line. This setting allows the interface to derive the transmit clock from the received clock. In certain circumstances, it might be appropriate to generate a clock from one of the internal sources (options module or chassis).
- Specify the keyword line to use a transmit clock on the line’s receive data stream.
- Specify the keywords internal module to use the line module’s internal clock.
- Specify the keywords internal chassis to use the router’s clock.
- On a cOC3/STM1 I/O module, you can configure some ports with internal clock sources and others with line clock sources. However, all ports with internal clock sources must use either the router’s clock or the module’s clock. You cannot configure some ports on the I/O module to use the router’s clock and others to use the module’s clock.
- To change the clock source of the ports on a cOC3/STM1 I/O module from the router’s clock to the module’s clock or vice versa, change the clock source of all ports firstly to the line setting, and then to the new internal clock setting.
- Example
  host1(config-controll)#clock source internal module
- Use the no version to revert to the default, line.
- See clock source.

controller sonet

- Use to select an interface on which you want to configure SONET or SDH.
- Use the interface specifier in slot/port:path-channel format (ERX14xx models, ERX7xx models, and the ERX310 Broadband Services Router ) or slot/adapter/port format (E120 and E320 routers). The E120 and E320 routers do not support path channelization, and therefore does not support the path-channel specifier.
- Example 1—Selects a SONET interface on ERX14xx models, ERX7xx models, or the ERX310 router
  host1(config)#controller sonet 4/0
- Example 2—Selects an SONET interface on the E320 router
  host1(config)#controller sonet 3/0/0
- There is no no version.
- See controller sonet.

description

- Use to assign a text description or an alias to an unchannelized SONET interface.
- You can use this command to help you identify the interface and keep track of interface connections.
- The description or alias can be a maximum of 64 characters.
- Use show controllers sonet to display the text description.
- Example
  host1(config-controll)#description boston-sonet-interface
- Use the no version to remove the text description or alias.
- See description.

path description

- Use to assign a text description or an alias to an unchannelized SONET path.
- You can use this command to help you identify the interface and keep track of interface connections.
- The description or alias can be a maximum of 64 characters.
- Example
  host1(config-controll)#path description westford
- Use the no version to remove the description.
- See path description.

path overhead c2

- Use to overwrite the automatic setting for the path signal label (C2) byte.
- By default, the value of the C2 byte for the path is determined by the layers configured above the SONET/SDH interface and set automatically. The E Series router sets this default value in accordance with RFC 2558. (See References.)

  | Caution: Use this command only if you know that the automatic setting does not match the setting on the remote device. Otherwise, the remote device might send an unexpected value, and the router might lose data.

- Do not specify a path identifier for unchannelized SONET/SDH interfaces.
- Example
  host1(config-controll)#path overhead c2 20
- Use the no version to restore the default setting, in which the value of the C2 byte is determined by the layers configured above the SONET/SDH interface.
- See path overhead c2.

path shutdown

- Use to disable a path.
- Paths are enabled by default.
- Example
  host1(config-controll)#path shutdown
- Use the no version to restart a disabled path.
- See path shutdown.

path snmp trap link-status

- Use to enable SNMP link-status processing for the path layer of the interface.
- The default is disabled.
- Do not specify a path identifier for unchannelized SONET/SDH interfaces.
- Example
  host1(config-controll)#path snmp trap link-status
- Use the no version to disable SNMP link status processing.
- See path snmp trap link-status.

path trigger alarm prdi

- Use to configure the router to use remote defect indications (RDIs) at the path layer to determine the operational status of a path.
- Do not specify a path identifier for unchannelized SONET/SDH interfaces.
- Example
  host1(config-controll)#path trigger alarm prdi
- Use the no version to restore the default setting, in which the software uses loss of pointer and AIS defects at the path layer to determine the operational status of a path.
- See path trigger alarm prdi.

path trigger delay

- Use to set the time that the router waits to set an alarm when the router records a defect at the path layer.
- Change this value from the default only when you are using MPLS fast reroute over a SONET/SDH interface.
  - Specify a value of 0 milliseconds if the interface does not use APS/MSP or if you want MPLS to have priority over APS/MSP.
  - Specify a value of at least 100 milliseconds if this interface uses APS/MSP and you want APS/MSP to have priority over MPLS.
- Do not specify a path identifier for unchannelized SONET/SDH interfaces.
- Example
  host1(config-controll)#path trigger delay msec 1000
- Use the no version to restore the default setting, 2500 milliseconds.
- See path trigger delay.

sdh

- Use to specify that the interface supports SDH.
- Example
  host1(config-controller)#sdh
- Use the no version to revert to SONET operation on this interface.
- See sdh.

shutdown

- Use to disable a SONET/SDH interface.
- SONET/SDH interfaces are enabled by default.
- Example
  host1 (config-controll)#shutdown
- Use the no version to restart a disabled interface.
- See shutdown.

snmp trap link-status

- Use to enable SNMP link-status processing for the section and line layers of the interface.
- The default is enabled.
- Example
  host1(config-controll)#no snmp trap link-status
- Use the no version to disable SNMP link status processing.
- See snmp trap link-status.

trigger delay

- Use to set the time that the router waits to set an alarm when the router records a defect at the line or section layer.
- Change this value from the default only when you are using MPLS fast reroute over a SONET/SDH interface.
  - Specify a value of 0 milliseconds if the interface does not use APS/MSP or if you want MPLS to have priority over APS/MSP.
  - Specify a value of at least 100 milliseconds if this interface uses APS/MSP and if you want APS/MSP to have priority over MPLS.
- Example
  host1(config-controll)#trigger delay msec 1000
- Use the no version to restore the default setting, 2500 milliseconds.
- See trigger delay.

## Configuring APS/MSP

For APS/MSP, you must configure a working interface and a corresponding protect interface. You must also assign each pair of working and protect interfaces to a unique group.

| Note: Configuring the working interface before you configure the protect interface is not required. You can configure the working interface before or after you configure the protect interface. The E120 and E320 routers does not support APS/MSP.

### Configuring the Working Interface

To configure the working interface:

1. Select the interface.
   host1(config)#controller sonet 4/0
2. Specify the APS group to which the working and protect interfaces will belong.
   host1(config-controll)#aps group boston
3. Specify the interface as the working interface.
   host1(config-controll)#aps working

aps group

- Use to specify the group to which the working and protect interfaces will belong.
- Specify the name of the APS group.
- Example
  host1(config-controll)#aps group boston
- Use the no version to remove a group of APS interfaces.
- See aps group.

aps working

- Use to specify the working interface.
- Optionally, you can specify 1 as the channel number for the working interface. Because the working interface is always assigned channel number 1, this is the only valid option.
- Examples
  host1(config-controll)#aps working host1(config-controll)#aps working 1
- Use the no version to prevent the interface from acting as a working interface.
- See aps working.

threshold

- Use to set thresholds for the bit error rates associated with APS/MSP alarms.
- This command does not apply to the working interface. You can issue this command only for the protect interface.
- Specify one of the following keywords to indicate the alarm level:
  - sd-ber—Bit error rate that specifies signal degradation
  - sf-ber—Bit error rate that specifies signal failure
- Specify an integer n in one of the following ranges, where n corresponds to a rate of 10-n (10e-n) errors per second.
  - For sd-ber, an integer in the range 5–9; the default value is 5
  - For sf-ber, an integer in the range 3–5; the default value is 3
- Example
  host1(config-controll)#threshold sf-ber 4
- Use the no version to restore the default, 5 (for sd-ber) or 3 (for sf-ber), for the specified alarm.
- See threshold.

### Configuring the Protect Interface

To configure the protect interface:

1. Select the interface.
   host1(config)#controller sonet 4/1
2. Specify the APS group to which the protect and working interfaces will belong.
   host1(config-controll)#aps group boston
3. Specify the protect interface.
   host1(config-controll)#aps protect
4. (Optional) Prevent the protect interface from taking over automatically if the working interface fails.
   host1(config-controll)#aps lockout
5. (Optional) Enable the router to revert to the working interface when it recovers.
   host1(config-controll)#aps revert 7
6. (Optional) Specify that switchover takes place in unidirectional mode.
   host1(config-controller)#aps unidirectional

aps group

- Use to specify the group to which the working and protect interfaces will belong.
- Specify the name of the APS group.
- Example
  host1(config-controll)#aps group boston
- Use the no version to remove a group of APS interfaces.
- See aps group.

aps lockout

- Use to prevent the protect interface from taking over if the working interface fails.
- You can issue this command only for the protect interface, not for the working interface.
- The aps lockout command has a higher priority than the aps force command, aps manual command, a remote reversion request, a signal failure request, or a signal degradation.
- Optionally, you can specify 0 as the channel number for the protect interface. Because the protect interface is always assigned channel number 0, this is the only valid option.
- The resulting configuration is stored in NVS for SRP module or line module reloads and SNMP.
- Examples
  host1(config-controll)#aps lockout host1(config-controll)#aps lockout 0
- Use the no version to restore the default situation, in which the protect interface can take over if the working interface fails.
- See aps lockout.

aps protect

- Use to configure an interface as a protect interface.
- You can issue this command only for the protect interface, not for the working interface.
- Optionally, you can specify 0 as the channel number for the protect interface. Because the protect interface is always assigned channel number 0, this is the only valid option.
- Examples
  host1(config-controll)#aps protect host1(config-controll)#aps protect 0
- Use the no version to remove the protect interface from the APS group.
- See aps protect.

aps revert

- Use to revert to the original working interface when it recovers.
- Specify the number of minutes in the range 5–7, after which the router will switch to the working interface.
- You can issue this command only for the protect interface, not for the working interface.
- Example
  host1(config-controll)#aps revert 7
- Use the no version to restore the default setting, in which the router does not revert to the working interface when it recovers.
- See aps revert.

aps unidirectional

- Use to specify that the router should switch to the protect interface using the unidirectional mode switching mechanism.
- You can issue this command only for the protect interface, not for the working interface.
- Example
  host1(config-controller)#aps unidirectional
- Use the no version to restore the default setting, bidirectional mode.
- See aps unidirectional.

### Configuring SONET/SDH Alarms

To configure the bit error rates that determine signal degradation and signal failure on the working interface:

1. Select the protect interface.
   host1(config)#controller sonet 4/1
2. Specify the bit error rate at which the router should generate an alarm indicating signal degradation.
   host1(config-controller)#threshold sd-ber 6
3. Specify the bit error rate at which the router should generate an alarm indicating signal failure and switch from the working interface to the protect interface.
   host1(config-controller)#threshold sf-ber 5

threshold

- Use to set thresholds for the bit error rates associated with APS/MSP alarms.
- You can issue this command only for the protect interface. It does not apply to the working interface.
- Specify one of the following keywords to indicate the alarm level:
  - sd-ber—Bit error rate that specifies signal degradation
  - sf-ber—Bit error rate that specifies signal failure
- Specify an integer n in one of the following ranges, where n corresponds to a rate of 10-n (10e-n) errors per second.
  - For sd-ber, an integer in the range 5–9; the default value is 5
  - For sf-ber, an integer in the range 3–5; the default value is 3
- Example
  host1(config-controll)#threshold sf-ber 4
- Use the no version to restore the default, 5 (for sd-ber) or 3 (for sf-ber), for the specified alarm.
- See threshold.

### Configuration Example

The following example shows how to configure working and protect interfaces for APS/MSP.

1. Configure the working interface.
   host1(config)#controller sonet 3/0 host1(config-controller)#aps group boston host1(config-controller)#aps working 1
2. Configure the protect interface.
   host1(config-controller)#controller sonet 3/1 host1(config-controller)#aps group boston host1(config-controller)#aps protect 0 host1(config-controller)#aps unidirectional host1(config-controller)#aps revert 30 host1(config-controller)#threshold sf-ber 4

### Configuring APS Event Collection

To configure line modules to deliver APS events to the necessary SNMP traps, issue the aps events command from Global Configuration mode.

aps events

- Use to enable line modules to deliver APS events to the necessary SNMP traps.
- Use the list variable to deliver the following types of APS events:
  - all—Configure notification of all APS events
  - channel-mismatch—Configure notification of APS channel mismatches
  - feplf—Configure notification of APS far-end protection line failures
  - mode-mismatch—Configure notification of APS mode mismatches
  - psbf—Configure notification of APS protection signal byte failures
  - switchover—Configure notification of APS switchovers
- Example
  host1(config)#aps events channel-mismatch
- Use the no version to disable the delivery of APS events from line modules to SNMP traps.
- See aps events.

## Manual Switching to a Redundant Port

To switch from the working interface to the protect interface manually, issue the aps force command or the aps manual command. The aps force command overrides any switchover settings you configured on the protect interface; the aps manual command does not override those settings.

aps force

- Use to switch from the working interface to the assigned protect interface unless a request of equal or higher priority is in effect.
- You can issue this command only for the protect interface, not for the working interface.
- The aps force command has a higher priority than the aps manual command, a remote reversion request, a signal failure request on a working channel, or a signal degradation request on a working channel.
- The resulting configuration is not stored in NVS for SRP module or line module reloads; however, it is stored in NVS for use with SNMP.
- You must specify one of the following channel numbers:
  - 0—Switches from the protect interface back to the working interface
  - 1—Switches from the working interface to the protect interface
- Examples
  host1(config-controll)#aps force 0 host1(config-controll)#aps force 1
- Use the no version to revert to the original working interface.
- See aps force.

aps manual

- Use to switch from the working interface to the protect interface unless a command of equal or higher priority is in effect.
- You can issue this command only for the working interface, not for the protect interface.
- The aps manual command has a higher priority than a remote reversion request.
- The resulting configuration is not stored in NVS for SRP module or line module reloads; however, it is stored in NVS for use with SNMP.
- You must specify one of the following channel numbers:
  - 0—Switches from the protect interface back to the working interface
  - 1—Switches from the working interface to the protect interface
- Examples
  host1(config-controll)#aps manual 0 host1(config-controll)#aps manual 1
- Use the no version to revert to the original working interface.
- See aps manual.