cc/td/doc/product/mels/15530/12_2_sv
hometocprevnextglossaryfeedbacksearchhelp
PDF

Table Of Contents

Configuring APS

About APS

About Splitter Protection

Considerations for Using Splitter Protection

Configuring Splitter Protection

Displaying the Splitter Protection Configuration

About Line Card Protection

About Client Based Line Card Protection

About Y-Cable Line Card Protection

Considerations for Using Y-Cable Based Line Card Protection

Configuring Y-Cable Based Line Card Protection

Displaying the Y-Cable Protection Configuration

About Switch Fabric Based Line Card Protection

Considerations for Using Switch Fabric Based Line Card Protection

Configuring Switch Fabric Based Line Card Protection

About Trunk Fiber Based Protection

Considerations for Using Trunk Fiber Protection

Configuring Trunk Fiber Protection

Displaying Trunk Fiber Protection Configuration

About Redundant Switch Fabric Protection

Configuring APS Group Attributes

Configuring Revertive Switching

About Unidirectional and Bidirectional Path Switching

Configuring Unidirectional and Bidirectional Path Switching

Configuring the Switchover-Enable Timer

About Switchovers and Lockouts

Requesting a Switchover or Lockout

Displaying Switchover and Lockout Request Status

Clearing Switchovers and Lockouts

Displaying Switchover and Lockout Clear Status


Configuring APS

This chapter describes how protection is implemented on the Cisco ONS 15530. It also describes how to configure splitter protection and line card protection with APS (Automatic Protection Switching). This chapter contains the following sections:

• About APS

• About Splitter Protection

• Configuring Splitter Protection

• About Line Card Protection

• About Client Based Line Card Protection

• About Y-Cable Line Card Protection

• Configuring Y-Cable Based Line Card Protection

• About Switch Fabric Based Line Card Protection

• Configuring Switch Fabric Based Line Card Protection

• About Trunk Fiber Based Protection

• Configuring Trunk Fiber Protection

• About Redundant Switch Fabric Protection

• Configuring APS Group Attributes

• About Switchovers and Lockouts

• Requesting a Switchover or Lockout

• Clearing Switchovers and Lockouts

About APS

APS provides protection against signal transmission failure. The Cisco ONS 15530 supports the following APS features:

•1+1 path protection

•Splitter protection

•Line card protection

–Client based

–Y-cable based

–Switch fabric based

•Trunk fiber protection

•Redundant switch fabric protection

•Bidirectional and unidirectional path switching

The 1+1 path protection architecture transmits the client signal on both the working and protection paths.

Note For an animated description of the APS implementation on the Cisco ONS 15530, go to the following URL:

http://www.cisco.com/mm/dyngraph/APS15530.html

About Splitter Protection

Splitter protection on the Cisco ONS 15530 provides protection against facility failure, such as trunk fiber cuts, but not ITU laser failures or client equipment failures. Splitter line cards internally replicate the client optical signal and transmit it to both OADM modules. The Cisco ONS 15530 supports splitter versions of the transponder line card, the 2.5-Gbps ITU trunk card, the 10-Gbps ITU tunable and non-tunable trunk card, and the 8-port multi-service muxponder.

Figure 12-1 shows splitter protection with a transponder line card.

Figure 12-1 Splitter Protection Scheme

On the ITU side, a fiber pair, with one receive fiber and one transmit fiber, connects to the OADM module transmitting in the west direction. Another fiber pair connects to the OADM module transmitting in the east direction. A 2x2 switch module on the line card receives both signals from the trunk fiber pairs and selects one as the active signal. When a signal failure is detected, the line card switches over to receive the standby signal. The standby signal then becomes the active signal.

Figure 12-2 shows splitter protection with a 10-Gbps ITU tunable or non-tunable trunk card.

Figure 12-2 Cisco ONS 15530 10-Gbps Tunable or Non-tunable Trunk Card Splitter Protection

Considerations for Using Splitter Protection

The following considerations apply when considering the use of splitter protection:

•Splitter protection does not protect against failure of the splitter line card. Splitter protection also does not protect against failure of a client line card or of the client equipment.

To protect against laser failure for transponder line cards, 2.5-Gbps ITU trunk card, and 10-Gbps ITU tunable and non-tunable trunk cards, use y-cable protection as described in the "About Line Card Protection" section and the "Configuring Y-Cable Based Line Card Protection" section. To protect against ESCON card failure or the client equipment, implement protection on the client equipment instead.

•A fully provisioned single shelf configuration can support 4 channels in splitter protection mode. A fully provisioned multiple shelf configuration can support up to 32 channels in splitter protection mode.

For more information about multiple shelf nodes, see Chapter 13, "Configuring Multiple Shelf Nodes."

•Splitter protection supports revertive behavior. With revertive APS, the signal automatically switches back to the working path after the receive signal defect has been corrected and the wait to restore timer is expired. The default behavior is nonrevertive. When defects on the working channel are cleared, a wait to restore timer is started. Once this timer expires, the working channel becomes the active channel if no other problems occur on the working path.

•For interfaces configured for splitter APS and either Sysplex ETR or Sysplex CLO protocol encapsulation, configure bidirectional path switching to ensure proper functioning of these protocols.

•For bidirectional path switching to function on the transponder line cards, the OSC is required for exchanging APS channel protocol messages. For bidirectional path switching on the 2.5-Gbps ITU trunk card, 10-Gbps ITU trunk card, or 10-Gbps ITU tunable trunk card, either the in-band message channel or the OSC can be used for the APS channel protocol messages.

For detailed information on shelf configuration rules, refer to the Cisco ONS 15530 Planning Guide.

Configuring Splitter Protection

To configure splitter protection, perform the following steps:

Step 1 Determine the number of channels you will deploy to transport client data.

Step 2 Ensure that the correct line cards are inserted in slots 1 through 4 or 7 through 10.

Step 3 Ensure that the line cards and modules are correctly interconnected with the external optical patch cables. For ring topologies, connect the thru interface on one OADM to the thru interface on the other.

Step 4 Configure the interfaces and the patch connections from the CLI (command-line interface).

Step 5 Configure APS from the CLI.

Caution Do not enable laser safety control with splitter protection. If you configure the system with splitter protection and enable laser safety control, the transmit laser shuts down when an open fiber occurs on one transport fiber and signal transmission to the client is interrupted.

To configure splitter protection, use the following commands, beginning in global configuration mode:

 
Command
Purpose

Step 1 

Switch(config)# redundancy

Switch(config-red)#

Enters redundancy configuration mode.

Step 2 

Switch(config-red)# associate group name

Switch(config-red-aps)#

Specifies an APS group name and enters APS configuration mode.

Note The group name is case sensitive.

Step 3 

Switch(config-red-aps)# aps working wavepatch slot/subcard/port

Configures the working path interface.

Step 4 

Switch(config-red-aps)# aps protection wavepatch slot/subcard/port

Configures the protection path interface.

Step 5 

Switch(config-red-aps)# aps enable

Enables APS activity between the interfaces.

Examples

This example shows how to associate wavepatch interfaces for the transponder line card in slot 3 for splitter protection.

Switch# configure terminal
Switch(config)# redundancy
Switch(config-red)# associate group dallas1
Switch(config-red-aps)# aps working wavepatch 3/0/0
Switch(config-red-aps)# aps protection wavepatch 3/0/1
Switch(config-red-aps)# aps enable

Displaying the Splitter Protection Configuration

To display the splitter protection configuration, use the following EXEC commands:

Command
Purpose

show aps

Displays the APS configuration summary.

show aps {detail | group name | interface wavepatch slot/subcard/port}

Displays detailed APS configuration information for groups and interfaces.

Note Group names are case sensitive.


Example

The following example shows how to display the APS splitter protection configuration:

Switch# show aps

AR : APS Role, Wk: Working, Pr: Protection
AS : APS State, Ac: Active, St: Standby, NA: Not Applicable
IS : Interface State, Up: Up, Dn: Down
MPL: Minimum Protection Level, SD: Signal Degrade, SF: Signal Failure
LOL: Loss of Light, - not currently protected

Interface AR AS IS MPL Redundant Intf Group Name
~~~~~~~~~~~~~~~~~~~~~ ~~ ~~ ~~ ~~~ ~~~~~~~~~~~~~~~~~~~~~ ~~~~~~~~~~~~~~~~~~~~
Wavepatch8/0/0 Wk Ac Up LOL Wavepatch8/0/1 Seattle
Wavepatch8/0/1 Pr St Up - Wavepatch8/0/0 Seattle

Switch# show aps group Seattle

APS Group Seattle :

architecture.: 1+1, remote prov: 1+1
span.........: end-to-end
prot. mode...: network side splitter
direction....: prov: uni, current: uni, remote prov: uni
revertive....: yes, wtr: 60 secs (not running)
aps state....: enabled (associated)
request timer: holddown: 5000 ms, max: 15000 ms, count 2
msg-channel..: auto (up on osc)
created......: 0 minutes
auto-failover: enabled
transmit k1k2: no-request, 0, 0, 1+1, uni
receive k1k2: no-request, 0, 0, 1+1, uni
switched chan: 0
protection(0): Wavepatch8/0/1 (STANDBY - UP)
: channel request: no-request
: switchover count: 0
: last switchover: never
working...(1): Wavepatch8/0/0 (ACTIVE - UP)
: channel request: no-request
: switchover count: 0
: last switchover: never

In show aps command, Signal degrade (SD) and signal failure (SF) indicates the signal quality based on the signal data stream. Signal degrade is reported when the number of errors reported per second is more than the signal degrade threshold. Signal failure is reported when the number of errors per second is more than the signal failure threshold. For more information on configuring SD and SF, refer to "Configuring Alarm Thresholds" section for each card interface.

About Line Card Protection

Line card protection on the Cisco ONS 15530 provides protection against both facility failures and line card failures. With line card protection, a duplicated signal is transmitted over ITU channels generated on separate line cards.

The Cisco ONS 15530 supports three types of line card protection:

•Client based protection

•Y-cable protection

•Switch fabric based protection

About Client Based Line Card Protection

In client protection mode, both signals are transmitted to the client system. The client system decides which signal to use and when to switch over.

Note Client protection does not require APS configuration on the Cisco ONS 15530.

Figure 12-3 shows an example of line card protection using transponder line cards.

Figure 12-3 Client Based Line Card Protection Using Transponder Line Cards

Figure 12-4 shows an example of line card protection using ESCON aggregation cards and 10-Gbps ITU trunk cards.

Figure 12-4 Client Based Line Card Protection Using ESCON Aggregation Cards and 10-Gbps ITU Trunk Cards

About Y-Cable Line Card Protection

With y-cable protection, the client equipment sends only one signal to two transponder line cards, two 4-port 1-Gbps/2-Gbps FC aggregation cards, or two 8-port FC/GE aggregation cards using a y-cable to replicate the signal. The client equipment receives from only one line card. The Cisco ONS 15530 turns on the laser at the active transparent interface, and turns off the laser on the standby transparent interface. At each receiver on the trunk side of the line card, the system monitors the optical signal power level. If the system detects a failure of the active signal when an acceptable signal exists on the standby line card, a switchover to the standby signal occurs by turning off the active transmitter at the client interface and turning on the standby transmitter. (See Figure 12-5.)

Note The ESCON aggregation cards and the 8-port multi-service muxponders do not support y-cable protection.

Figure 12-5 Y-Cable Based Line Card Protection Scheme

Considerations for Using Y-Cable Based Line Card Protection

The following considerations apply when considering the use of line card protection:

•Y-cable line card protection does not protect against failures of the client equipment. To protect against client failures, ensure that protection is implemented on the client equipment itself.

•A fully provisioned single shelf configuration can support up to 4 channels with line card protection using transponder line cards. A fully provisioned multiple shelf configuration can support up to 32 channels in line card protection mode.

For more information about multiple shelf nodes, see Chapter 13, "Configuring Multiple Shelf Nodes."

•Y-cable line card protection supports revertive behavior. With revertive behavior, the signal automatically switches back to the working path after the signal failure has been corrected. The default behavior is nonrevertive.

•You can terminate the client signal on line cards that support the same channel by simplifying system management. In this way the client signal maps to the same WDM wavelength on both the working and protection paths.

Caution Do not configure y-cable protection with Sysplex CLO, Sysplex ETR, or ISC compatibility protocol encapsulation, or with the OFC safety protocol.

Proper physical configuration of the system is critical to the operation of line card protection. For detailed information on shelf configuration rules, refer to the Cisco ONS 15530 Planning Guide.

Configuring Y-Cable Based Line Card Protection

To configure line card protection, perform the following steps:

Step 1 Determine the number of clients you need to support and which channels you need to deploy to transport the client data.

Step 2 Ensure that the OADM modules needed to support the deployed channels are installed in the shelf. (See the "Considerations for Using Y-Cable Based Line Card Protection" section.)

Step 3 Ensure that the OADM modules are correctly interconnected with the external optical patch cables.

Step 4 Ensure that there are separate paths to the OADM modules, by shutting down the unused wavepatch interfaces if you are using splitter line cards.

Step 5 Configure the interfaces and the patch connections from the CLI.

Step 6 Configure y-cable protection from the CLI.

Y-cable protection on the Cisco ONS 15530 requires configuration on the CLI. To configure y-cable protection, use the following commands, beginning in global configuration mode:

 
Command
Purpose

Step 1 

Switch(config)# redundancy

Switch(config-red)#

Enters redundancy configuration mode.

Step 2 

Switch(config-red)# associate group name

Switch(config-red-aps)#

Specifies an APS group name and enters APS configuration mode.

Note The group name is case sensitive.

Step 3 

Switch(config-red-aps)# aps working {transparent | gigabitphy | twogigabitphy} slot/subcard/port

Configures the working path interface.

Step 4 

Switch(config-red-aps)# aps protection {transparent | gigabitphy | twogigabitphy} slot/subcard/port

Configures the protection path interface.

Step 5 

Switch(config-red-aps)# aps y-cable

Enables y-cable protection. The default state is no y-cable protection (disabled).

Step 6 

Switch(config-red-aps)# aps enable

Enables APS activity between the interfaces.

Caution Do not configure y-cable protection with Sysplex CLO, Sysplex ETR, or ISC compatibility protocol encapsulation, or with the OFC safety protocol.

Example

This example shows how to associate two transparent interfaces for y-cable line card protection.

Switch# configure terminal
Switch(config)# redundancy
Switch(config-red)# associate group Yosemite
Switch(config-red-aps)# aps working transparent 3/0/0
Switch(config-red-aps)# aps protection transparent 4/0/0
Switch(config-red-aps)# aps y-cable
Switch(config-red-aps)# aps enable
Switch(config-red-aps)# end
Switch#

Displaying the Y-Cable Protection Configuration

To display the y-cable protection configuration, use the following EXEC command:

Command
Purpose

show aps

Displays the APS configuration summary.

show aps {detail | group name | interface [transparent | gigabitphy | twogigabitphy] slot/subcard/port}

Displays detailed APS configuration information for interfaces and groups.

Note Group names are case sensitive.


Example

The following example shows how to display the y-cable protection for an APS group:

Switch# show aps

AR : APS Role, Wk: Working, Pr: Protection
AS : APS State, Ac: Active, St: Standby, NA: Not Applicable
IS : Interface State, Up: Up, Dn: Down
MPL: Minimum Protection Level, SD: Signal Degrade, SF: Signal Failure
LOL: Loss of Light, - not currently protected

Interface AR AS IS MPL Redundant Intf Group Name
~~~~~~~~~~~~~~~~~~~~~ ~~ ~~ ~~ ~~~ ~~~~~~~~~~~~~~~~~~~~~ ~~~~~~~~~~~~~~~~~~~~
Transparent4/0/0 Wk St Up - Transparent7/0/0 Yosemite
Transparent7/0/0 Pr Ac Up SD Transparent4/0/0 Yosemite

Switch# show aps group Yosemite

APS Group Yosemite :

architecture.: 1+1, remote prov: 1+1
span.........: end-to-end
prot. mode...: client side y-cable
direction....: prov: bi, current: bi, remote prov: bi
revertive....: no
aps state....: enabled (associated)
request timer: holddown: 5000 ms, max: 15000 ms, count 2
msg-channel..: auto (up on osc)
created......: 17 hours, 10 minutes
auto-failover: enabled
transmit k1k2: reverse-request, 1, 1, 1+1, bi
receive k1k2: forced-switch, 1, 1, 1+1, bi
switched chan: 1
protection(0): Transparent7/0/0 (ACTIVE - UP), Wave7/0 (UP)
: channel request: no-request
: switchover count: 2
: last switchover: 15 hours, 14 minutes
working...(1): Transparent4/0/0 (STANDBY - UP), Wave4/0 (UP)
: channel request: no-request
: switchover count: 3
: last switchover: 14 hours, 41 minutes

About Switch Fabric Based Line Card Protection

The Cisco ONS 15530 provides protection for cross connections through the switch fabric. Switch fabric based line card protection is supported on systems with one or two switch fabrics.

The aggregated signals from the aggregation cards cross connect through the switch fabric to a 2.5-Gbps ITU trunk card, 10-Gbps ITU tunable or non-tunable trunk card, or 10-Gbps uplink card. In switch fabric based line card protection, the system sets up a protection cross connection through the switch fabric to a second 2.5-Gbps ITU trunk card, 10-Gbps ITU tunable or non-tunable trunk card, or a 10-Gbps uplink card (see Figure 12-6).

Figure 12-6 Switch Fabric Based Line Card Protection with Redundant Switch Fabrics

Switch fabric based line card protection protects against facility failures and failures in 2.5-Gbps ITU trunk cards, 10-Gbps ITU trunk cards, 10-Gbps ITU tunable trunk cards, and 10-Gbps uplink cards.

Note Splitter protection and Y-cable protection cannot be configured with switch fabric based protection.

Considerations for Using Switch Fabric Based Line Card Protection

The following considerations apply when considering the use of line card protection:

•Switch fabric based line card protection does not protect against failures of the client equipment or the ESCON aggregation card. To protect against such failures, use client based line card protection.

•A fully provisioned single shelf configuration can support up to two channels with switch fabric based line card protection. A fully provisioned multiple shelf configuration can support up to 32 channels in switch fabric based line card protection mode.

For more information about multiple shelf nodes, see Chapter 13, "Configuring Multiple Shelf Nodes."

•Switch fabric based line card protection supports revertive behavior. With revertive behavior, the signal automatically switches back to the working path after the signal failure has been corrected. The default behavior is nonrevertive.

•You can terminate the client signal on line cards of the same channel by simplifying system management. In this way the client signal maps to the same WDM wavelength on both the working and protection paths.

•You can configure unique flow identifiers on the ESCON aggregation card interfaces. Duplicate flow identifiers interfere with switchovers between line cards.

•Be sure that the subinterface on the protection line card does not have a configured cross connection. Such cross connection interfere with switchovers.

Proper physical configuration of the system is critical to the operation of switch fabric based line card protection. For detailed information on shelf configuration rules, refer to the Cisco ONS 15530 Planning Guide.

Configuring Switch Fabric Based Line Card Protection

To configure switch fabric based line card protection, use the following commands:

 
Command
Purpose

Step 1 

Switch# show connect

Displays the cross connect configuration.

Step 2 

Switch# configure terminal

Switch(config)#

Enters global configuration mode.

Step 3 

Switch(config)# connect {waveethernetphy | tengigethernetphy} slot/subcard [subinterface] portgroup slot/subcard/port [override]

Configures cross connections on the line card.

Step 4 

Switch(config)# redundancy

Switch(config-red)#

Enters redundancy configuration mode.

Step 5 

Switch(config-red)# associate group name

Switch(config-red-aps)#

Specifies an APS group name and enters APS configuration mode.

Note The group name is case sensitive.

Step 6 

Switch(config-red-aps)# aps working {waveethernetphy | tengigethernetphy} slot/subcard

Configures the working path interface.

Caution Configuring the working path on the standby cross connection might cause a switchover. Configure the working path on the active cross connection to prevent such switchovers when the APS group is enabled.

Step 7 

Switch(config-red-aps)# aps protection {waveethernetphy | tengigethernetphy} slot/subcard

Configures the protection path interface.

Step 8 

Switch(config-red-aps)# aps enable

Enables APS activity between the interfaces.

Note When configuring the esconphy interfaces, use unique flow identifiers for each esconphy interface on the system. For more information on configuring esconphy interfaces, see the "Configuring ESCON Aggregation Card Interfaces" section on page 4-3.

Note You can configure cross connections on either the working or the protection 2.5-Gbps ITU trunk cards, 10-Gbps ITU trunk cards, 10-Gbps ITU tunable trunk cards, or 10-Gbps uplink cards.

Displaying Switch Fabric Based Protection Configuration

To display the switch fabric based protection configuration, use the following EXEC command:

Command
Purpose

show aps [detail | group name | interface {waveethernetphy | tengigethernetphy} slot/subcard]

Displays the APS configuration.


Example

The following example shows how to display the switch fabric based line card protection:

Switch# show aps detail

APS Group yellow :

  architecture.: 1+1, remote prov: 1+1
span.........: end-to-end
prot. mode...: switch fabric based line card protection
direction....: prov: bi, current: bi, remote prov: bi
revertive....: no
aps state....: enabled (associated)
request timer: holddown: 5000 ms, max: 15000 ms, count 2
msg-channel..: auto-select (up on cdl dcc)
created......: 0 minutes
auto-failover: enabled
transmit k1k2: no-request, 0, 0, 1+1, bi
receive k1k2: no-request, 0, 0, 1+1, bi
switched chan: 0
protection(0): WaveEthernetPhy8/0 (STANDBY - UP), xc DORMANT
: channel request: no-request
: switchover count: 0
: last switchover: never
working...(1): WaveEthernetPhy7/0 (ACTIVE - UP), xc UP
: channel request: no-request
: switchover count: 0
: last switchover: never

About Trunk Fiber Based Protection

The PSM (protection switch module) provides trunk fiber based protection for Cisco ONS 15530 systems configured in point-to-point topologies. This type of protection only provides protection against trunk fiber cuts, not specific channel failure as provided by splitter and line card based schemes. However, this protection scheme allows for much simpler shelf configurations in topologies where per channel protection is not required.

Figure 12-7 shows trunk fiber based protection configured with a transponder line card.

Figure 12-7 Trunk Fiber Based Protection with a Transponder Line Card

Considerations for Using Trunk Fiber Protection

The following considerations apply when using trunk fiber protection:

•Trunk fiber protection does not protect against failures on the shelf itself or the client equipment. To protect against these failures, line card protection should be implemented on the client equipment itself.

•The APS software that supports trunk fiber based protection can be configured as revertive or nonrevertive. After a switchover, the active traffic can be put back on the previously failed working fiber, once the fault has been remedied, either automatically (revertive) or through manual intervention (nonrevertive).

•You can use PSMs only in point-to-point topologies.

•In multiple shelf nodes, the shelf connected to the trunk fiber must use a PSM.

•The point-to-point topology can have no more than two EDFAs. The cumulative noise of three or more EDFAs interferes with detecting the data channel loss on the PSM.

•When EDFAs are present in the topology, the power of the data channels at the PSM receiver must be greater than the cumulative noise of the EDFAs.

•Up to four channels on a single shelf can be protected with trunk fiber based protection.

Configuring Trunk Fiber Protection

To configure trunk fiber protection on the wdmsplit interfaces, perform the following steps, beginning in global configuration mode:

 
Command
Purpose

Step 1 

Switch(config)# redundancy

Switch(config-red)#

Enters redundancy mode.

Step 2 

Switch(config-red)# associate group name

Switch(config-red-aps)#

Specifies an APS group name and enters APS configuration mode.

Note The group name is case sensitive.

Step 3 

Switch(config-red-aps)# aps working wdmsplit slot/subcard

Configures the working path interface.

Step 4 

Switch(config-red-aps)# aps protection wdmsplit slot/subcard

Configures the protection path interface.

Step 5 

Switch(config-red-aps)# aps message-channel {auto-select | inband dcc | ip | osc} far-end name

Configures the name of the corresponding APS group on the other node in the topology.

Step 6 

Switch(config-red-aps)# aps enable

Enables APS activity between the interfaces.

Examples

The following example shows how to configure trunk fiber protection:

Switch(config)# redundancy
Switch(config-red)# associate group psm-group
Switch(config-red-aps)# aps working wdmsplit 0/1/0
Switch(config-red-aps)# aps protection wdmsplit 0/1/1
Switch(config-red-aps)# aps message-channel auto-select far-end group-name psm-group
Switch(config-red-aps)# aps enable

Displaying Trunk Fiber Protection Configuration

To display the trunk fiber configuration, use the following EXEC command:

Command
Purpose

show aps [detail | group name | interface wdmsplit slot/subcard/port]

Displays the APS configuration for interfaces and groups.

Note Group names are case sensitive.


Examples

The following example shows how to display the protocol encapsulation configuration of a wdmsplit interface:

Switch# show aps group psm-group
APS Group psm-group :

architecture.:1+1, remote prov:uni
span.........:end-to-end
prot. mode...:network side wdm splitter
direction....:prov:uni, current:uni, remote prov:uni
revertive....:no
aps state....:enabled (associated)
request timer:holddown:5000 ms, max:15000 ms, count 2
msg-channel..:auto (down), psm-group
created......:2 minutes
auto-failover:disabled
transmit k1k2:sf-lp, 0, 0, 1+1, uni
receive k1k2:no-request, 0, 0, unknown, unknown
switched chan:0
protection(0):WdmSplit0/0/1 (STANDBY - UP)
:channel request:sf-lp
:switchover count:1
:last switchover:0 minutes
working...(1):WdmSplit0/0/0 (ACTIVE - UP)
:channel request:sf-lp
:switchover count:1
:last switchover:0 minutes

About Redundant Switch Fabric Protection

The Cisco ONS 15530 provides protection for the 2.5-Gbps aggregated signals sent through the redundant switch fabrics. The switch fabrics connect signals from client side line cards, such as the ESCON aggregation card, to ITU side line cards, such as the 10-Gbps ITU trunk card (see Figure 12-8). When a shelf is configured for CPU switch module redundancy, the redundant switch fabric increases system availability by protecting against switch fabric failures.

Figure 12-8 Redundant Switch Fabrics

Configuring APS Group Attributes

This section describes APS group attributes and how to configure them.

Configuring Revertive Switching

The Cisco ONS 15530 supports revertive switching for all types of protection. When revertive switching is configured, the system automatically switches back from the protection interface to the working interface. This automatic switchover occurs after the condition that caused the switchover to the protection interface is resolved and the switchover-enable timer has expired.

To configure revertive switching, use the following commands, beginning in global configuration mode:

 
Command
Purpose

Step 1 

Switch(config)# redundancy

Switch(config-red)#

Enters redundancy configuration mode.

Step 2 

Switch(config-red)# associate group name

Switch(config-red-aps)#

Selects the interfaces to associate and enters APS configuration mode.

Note The group name is case sensitive.

Step 3 

Switch(config-red-aps)# aps disable

Disables APS activity between the interfaces.

Step 4 

Switch(config-red-aps)# aps timer wait-to-restore seconds

Modifies the interval for the wait-to-restore timer. If revertive protection is configured and a switchover has occurred, the system will wait this amount of time before switching back to the functioning working path. The default value is 300 seconds. (Optional)

Step 5 

Switch(config-red-aps)# aps revertive

Enables revertive switchover behavior. The default behavior is nonrevertive.

Step 6 

Switch(config-red-aps)# aps enable

Enables APS activity between the interfaces.

Displaying the Revertive Switching Configuration

To display the revertive switching configuration, use the following EXEC command:

Command
Purpose

show aps [detail | group name | interface {transparent slot/subcard/0 | wavepatch slot/subcard/port | waveethernetphy slot/subcard | gigabitphy slot/subcard/port | wdmsplit slot/subcard/port}]

Displays the APS configuration for interfaces and groups.

Note Group names are case sensitive.


Example

The following example shows how to display the path switching configuration for an APS group named blue:

Switch# show aps group blue

APS Group blue:

architecture.: 1+1, remote prov: 1+1
span.........: end-to-end
prot. mode...: client side y-cable
direction....: prov: uni, current: uni, remote prov: uni
   revertive....: yes, wtr: 300 secs (not running)
aps state....: enabled (associated)
request timer: holddown: 5000 ms, max: 15000 ms, count 2
msg-channel..: auto (up on osc)
created......: 4 days, 23 hours, 16 minutes
auto-failover: enabled
transmit k1k2: no-request, 0, 0, 1+1, uni
receive k1k2: no-request, 0, 0, 1+1, uni
switched chan: 0
protection(0): Transparent7/0/0 (STANDBY - UP), Wave7/0 (UP)
: channel request: no-request
: switchover count: 2
: last switchover: 3 days, 23 hours, 16 minutes
working...(1): Transparent4/0/0 (ACTIVE - UP), Wave4/0 (UP)
: channel request: no-request
: switchover count: 1
: last switchover: 4 days, 53 minutes

About Unidirectional and Bidirectional Path Switching

The Cisco ONS 15530 supports per-channel unidirectional and bidirectional 1+1 path switching. When a signal is protected and the signal fails or degrades on the active path, the system automatically switches the APS group from the active network path to the standby network path.

Signal failures can be total LOL (Loss of Light) caused by laser failures, by fiber cuts between the Cisco ONS 15530 and the client equipment, between two Cisco ONS 15530s, or by other equipment failures. LOL failures on the transponder line cards and LOL (Loss of Lock) on the 2.5-Gbps ITU trunk cards, 10-Gbps ITU trunk cards, 10-Gbps ITU tunable trunk cards, and 10-Gbps uplink cards cause switchovers for protected signals.

For y-cable APS, you can also configure alarm thresholds to cause a switchover when the error rate detected on the signal reaches an unacceptable level. For information about configuring alarm thresholds, see the "Configuring Alarm Thresholds" section on page 4-10.

The Cisco ONS 15530 implements path switching using a SONET-compliant APS channel protocol over the in-band message channel or the OSC (optical supervisory channel).

Note Bidirectional path switching operates only on networks that support the OSC or the in-band message channel.

Figure 12-9 shows a simple point-to-point configuration with splitter protection. The configured working path carries the active signal, and the configured protection path carries the standby signal.

Figure 12-9 Active and Standby Path Configuration Example

Figure 12-10 shows the behavior of unidirectional path switching when a loss of signal occurs. In the two node example network, unidirectional path switching operates as follows:

•Node 2 sends the signal over both the active and standby paths.

•Node 1 receives both signals and selects the signal on the active path.

•Node 1 detects a loss of signal light on its active path and switches over to the standby path.

•Node 2 does not switch over and continues to receive its original active path.

Now the nodes are communicating along different paths.

Figure 12-10 Unidirectional Path Switching Example

Figure 12-11 shows the behavior of bidirectional path switching when a loss of signal occurs. In the two node example network, bidirectional path switching operates as follows:

•Node 2 sends the signal over both the active and standby paths.

•Node 1 receives both signals and selects the signal on the active path.

•Node 1 detects a loss of signal light on its active path and switches over to the standby path.

•Node 1 sends an APS message to node 2 on the protection path indicating that it has switched.

•Node 2 processes the APS message and switches from the active path to the standby path.

Both node 1 and node 2 communicate on the same path.

Figure 12-11 Bidirectional Path Switching Overview

About APS Switching for Cisco ONS 15216 OADMs

The Cisco ONS 15530 can be connected to Cisco ONS 15216 OADMs in place of native Cisco ONS 15530 OADMs. However, this configuration does not support the Cisco ONS 15530 OSC channel (33rd channel, 1562.23 nm). For bidirectional path switching to function in this configuration, the APS message channel must operate through IP over the NME (Network Management Ethernet) on the CPU switch card. The Ethernet management ports of all the Cisco ONS 15530 and Cisco ONS 15216 systems at the site must connect to a single Ethernet switch, such as the Catalyst 2950, and must be managed over a single VLAN.

Configuring Unidirectional and Bidirectional Path Switching

To configure unidirectional or bidirectional path switching, use the following commands, beginning in global configuration mode:

 
Command
Purpose

Step 1 

Switch(config)# redundancy

Switch(config-red)#

Enters redundancy configuration mode.

Step 2 

Switch(config-red)# associate group name

Switch(config-red-aps)#

Selects the interfaces to associate and enters APS configuration mode.

Note The group name is case sensitive.

Step 3 

Switch(config-red-aps)# aps disable

Disables APS activity between the interfaces.

Step 4 

Switch(config-red-aps)# aps direction {unidirectional | bidirectional}

Specifies the type of path switching. The default behavior is unidirectional.

Step 5 

Switch(config-red-aps)# aps timer message holddown milliseconds count number

Changes the APS Channel Protocol holddown timer and message count values. The default is 5000 milliseconds and a count of 2. (Optional)

Step 6 

Switch(config-red-aps)# aps timer message max-interval seconds

Changes the APS Channel Protocol maximum interval timer for waiting for a message. The default is 15 seconds. (Optional)

Repeat Step 1 through Step 6 on the corresponding transparent interface on the other node that adds and drops, or terminates, the channel.

Step 7 

Switch(config-red-aps)# aps message-channel {auto-select [far-end group-name name] | inband dcc [far-end group-name name] | ip far-end group-name name ip-address ip-address | osc [far-end group-name name]}

Configures the message channel for the APS channel protocol messages. The default is auto-select without a group name. (Optional)

Note For node configurations using Cisco ONS 15216 OADMs exclusively, use ip for the APS message channel.

Step 8 

Switch(config-red-aps)# aps revertive

Configures revertive path switching. Default is nonrevertive.

Step 9 

Switch(config-red-aps)# aps enable

Enables APS activity between the interfaces.

Note Both nodes in the network that add and drop the channel must have the same APS configuration. Specifically, both must have the same path switching behavior, and working and protection paths.

Note For interfaces with either Sysplex ETR or Sysplex CLO protocol encapsulation, configure bidirectional path switching to ensure proper functioning of the protocol.

Examples

Figure 12-12 shows the active and standby paths between two Cisco ONS 15530 nodes, node 1 and node 2, with splitter protection.

Figure 12-12 Bidirectional Path Switching Example with Splitter Protection

The following example shows how to configure one channel in the example network for bidirectional path switching using the default working and protection path interfaces:

Node1# configure terminal
Node1(config)# redundancy
Node1(config-red)# associate group red
Node1(config-red-aps)# aps working wavepatch 4/0/0
Node1(config-red-aps)# aps protection wavepatch 4/0/1
Node1(config-red-aps)# aps direction bidirectional
Node1(config-red-aps)# aps enable

Node2# configure terminal
Node2(config)# redundancy
Node2(config-red)# associate group red
Node2(config-red-aps)# aps working wavepatch 4/0/0
Node2(config-red-aps)# aps protection wavepatch 4/0/1
Node2(config-red-aps)# aps bidirectional
Node2(config-red-aps)# aps enable

Figure 12-13 shows the active and standby paths between two Cisco ONS 15530 nodes, node 1 and node 2 with y-cable protection.

Figure 12-13 Bidirectional Path Switching Example with Y-Cable Protection

The following example shows how to configure one channel in the example network for bidirectional path switching and configure the working and protection path interfaces:

Node1# configure terminal
Node1(config)# redundancy
Node1(config-red)# associate group alpha
Node1(config-red-aps)# aps working transparent 4/0/0
Node1(config-red-aps)# aps protection transparent 3/0/0
Node1(config-red-aps)# aps direction bidirectional
Node1(config-red-aps)# aps y-cable
Node1(config-red-aps)# aps enable

Node2# configure terminal
Node2(config)# redundancy
Node2(config-red)# associate group alpha
Node2(config-red-aps)# aps working transparent 4/0/0
Node2(config-red-aps)# aps protection transparent 3/0/0
Node2(config-red-aps)# aps direction bidirectional
Node2(config-red-aps)# aps y-cable
Node2(config-red-aps)# aps enable

Figure 12-14 shows the configuration two Cisco ONS 15530 nodes, node 1 and node 2, using Cisco ONS 15216 OADMs and the NME to manage the APS switchovers.

Figure 12-14 Bidirectional Path Switching Example with Cisco ONS 15216 OADMs

The following example shows how to configure one channel in the example network for bidirectional path switching using the NME to manage APS switchovers and configure the working and protection path interfaces:

Node1# configure terminal
Node1(config)# interface fastethernet 0
Node1(config-if)# ip address 172.16.22.125 255.255.255.0
Node1(config-if)# no shutdown
Node1(config-if)# exit
Node1(config)# redundancy
Node1(config-red)# associate group one
Node1(config-red-aps)# aps working transparent 4/0/0
Node1(config-red-aps)# aps protection transparent 3/0/0
Node1(config-red-aps)# aps direction bidirectional
Node1(config-red-aps)# aps revertive
Node1(config-red-aps)# aps message-channel far-end group-name one ip-address 172.16.22.126
Node1(config-red-aps)# aps y-cable
Node1(config-red-aps)# aps enable
Node1(config-red-aps)# exit
Node1#

Cat2950-1# configure terminal
Cat2950-1(config)# interface gigabitethernet 0/1
Cat2950-1(config-if)# channel-group 1 mode on
Cat2950-1(config-if)# exit
Cat2950-1(config)# interface gigabitethernet 0/2
Cat2950-1(config-if)# channel-group 1 mode on
Cat2950-1(config-if)# exit
Cat2950-1(config)# interface vlan1
Cat2950-1(config-if)# ip address 10.0.0.1 255.255.255.0
Cat2950-1(config-if)# end
Cat2950-1#

Node2# configure terminal
Node2(config)# interface fastethernet 0
Node2(config-if)# ip address 172.16.22.126 255.255.255.0
Node2(config-if)# no shutdown
Node2(config-if)# exit
Node2(config)# redundancy
Node2(config-red)# associate group one
Node2(config-red-aps)# aps working transparent 4/0/0
Node2(config-red-aps)# aps protection transparent 3/0/0
Node2(config-red-aps)# aps direction bidirectional
Node2(config-red-aps)# aps revertive
Node2(config-red-aps)# aps message-channel far-end group-name one ip-address 172.16.22.125
Node2(config-red-aps)# aps y-cable
Node2(config-red-aps)# aps enable
Node2(config-red-aps)# exit
Node2#

Cat2950-2# configure terminal
Cat2950-2(config)# interface gigabitethernet 0/1
Cat2950-2(config-if)# channel-group 1 mode on
Cat2950-2(config-if)# exit
Cat2950-2(config)# interface gigabitethernet 0/2
Cat2950-2(config-if)# channel-group 1 mode on
Cat2950-2(config-if)# exit
Cat2950-2(config)# interface vlan1
Cat2950-2(config-if)# ip address 10.0.0.3 255.255.255.0
Cat2950-2(config-if)# end
Cat2950-2#

Displaying the Unidirectional and Bidirectional Path Switching Configuration

To display the path switching configuration, use the following EXEC command:

Command
Purpose

show aps [detail | group name | interface {transparent slot/subcard/0 | wavepatch slot/subcard/port | waveethernetphy slot/subcard/0 | gigabitphy slot/subcard/port | wdmsplit slot/subcard/port}]

Displays the APS configuration for interfaces and groups.

Note Group names are case sensitive.


Example

The following example shows how to display the path switching configuration for an APS group named blue:

Switch# show aps group blue

APS Group blue:

architecture.: 1+1, remote prov: 1+1
span.........: end-to-end
   direction....: prov: bi, current: bi, remote prov: bi
revertive....: no
  msg-channel..: auto (up on osc)
  created......: 26 minutes
aps state....: associated
   request timer: holddown: 5000 ms, max: 15 secs, count 2
  transmit k1k2: reverse-request, 1, 1, 1+1, bi
receive k1k2: forced-switch, 1, 1, 1+1, bi
  switched chan: 0
channel ( 0): Wavepatch8/0/1 (STANDBY - UP)
: channel request: no-request
: transmit request: no-request
: receive request: no-request
channel ( 1): Wavepatch8/0/0 (ACTIVE - UP)
: channel request: no-request
: switchover count: 0
: last switchover: never

Configuring the Switchover-Enable Timer

The switchover-enable timer on the Cisco ONS 15530 prevents any automatic switchover from the protection path to the working path until it has expired. When it expires, switchovers occur only if there is no fault on the working path and there is no overriding switchover request in effect.

To configure the switchover-enable timer, use the following commands, beginning in global configuration mode:

 
Command
Purpose

Step 1 

Switch(config)# redundancy

Switch(config-red)#

Enters redundancy configuration mode.

Step 2 

Switch(config-red)# associate group name

Switch(config-red-aps)#

Selects the interfaces to associate and enters APS configuration mode.

Note The group name is case sensitive.

Step 3 

Switch(config-red-aps)# aps disable

Disables the APS group.

Step 4 

Switch(config-red-aps)# aps timer switchover-enable min-interval seconds

Modifies the timer that controls the check on the status of the working path. The default is 3 seconds.

Step 5 

Switch(config-red-aps)# aps enable

Enables the APS group.

Displaying the Switchover-Enable Timer Configuration

To display the switchover-enable timer configuration, use the following EXEC command:

Command
Purpose

show aps [detail | group name | interface {transparent slot/subcard/0 | wavepatch slot/subcard/port | waveethernetphy slot/subcard | gigabitphy slot/subcard/port | wdmsplit slot/subcard/port}]

Displays the APS configuration for interfaces and groups.

Note Group names are case sensitive.


Example

The following example shows how to display the path switching configuration for an APS group named blue:

Switch# show aps group blue

APS Group blue:

architecture.: 1+1, remote prov: 1+1
span.........: end-to-end
   direction....: prov: bi, current: bi, remote prov: bi
   revertive....: yes
  msg-channel..: auto (up on osc)
  created......: 26 minutes
aps state....: associated
request timer: holddown: 5000 ms, max: 15 secs, count 2
  transmit k1k2: reverse-request, 1, 1, 1+1, bi
receive k1k2: forced-switch, 1, 1, 1+1, bi
  switched chan: 0
channel ( 0): Wavepatch8/0/1 (STANDBY - UP)
: channel request: no-request
: transmit request: no-request
: receive request: no-request
channel ( 1): Wavepatch8/0/0 (ACTIVE - UP)
: channel request: no-request
: switchover count: 0
: last switchover: never

About Switchovers and Lockouts

In APS, you can switch a channel signal from one path to another, or you can lock out a switchover altogether while performing system maintenance.

A switchover of the channel signal from the working path to protection path is useful when upgrading or maintaining the system, or in cases where a signal failure caused a switchover. The switchover to the formerly failed interface must be requested from the CLI. The interface originally configured as the working path might be preferred because of its link loss characteristics or because of its distance advantage. For example, some protocols, such as ESCON, experience lower data throughput at increasing distances, so moving the signal back to the shorter path might be advised.

A lockout prevents a switchover of the active signal from the working path to the protection path. This is useful when upgrading or maintaining the system, or repairing the protection path when it degrades or fails.

The Cisco ONS 15530 supports APS switchover and lockout requests from the CLI. These requests have priorities depending on the condition of the protection signal and the existence of other switchover requests. There are three types of switchover requests:

•Lockout requests—Have the highest priority and take effect regardless of the condition of the protection signal. A lockout prevents the active signal from switching over from the working path to the protection path.

•Forced switchover requests—Have the next highest priority and are only prevented if there is an existing lockout on the protection path, or the signal on the protection path has failed when switching from working to protection.

•Manual switchover requests—Have the lowest priority and are only honored if there is no lockout, forced switchover, or signal failure or degrade.

In summary, the priority order is:

1. Lockout

2. Signal failure on the protection path

3. Forced switchover

4. Signal failure on the working path

5. Signal degrade on the protection path

6. Signal degrade on the working path

7. Manual switchover

If a request or condition of a higher priority is in effect, a lower priority request is rejected.

Note APS lockouts and forced or manual switchover requests do not persist across processor card switchovers or system reloads.

Requesting a Switchover or Lockout

To prevent switchovers to the protection signal, or to request a signal switchover, use the following commands in privileged EXEC mode:

Command
Purpose

aps lockout group-name

Locks out all switchovers to the protection path.

aps switch group-name {force | manual} {protection-to-working | working-to-protection}

Requests a signal switchover of the active signal from the working path to the protection path, or vice versa, within an associated interface pair.


Examples

The following example shows how to request a forced switchover from working to protection except if a lockout is in effect on the protection path:

Switch# aps switch blue force working-to-protection

The following example shows how to prevent a switchover to the protection path:

Switch# aps lockout blue

Displaying Switchover and Lockout Request Status

To display a pending switchover request, use the following command in privileged EXEC mode:

Command
Purpose

show aps [detail | group name | interface {transparent slot/subcard/0 | wavepatch slot/subcard/port | waveethernetphy slot/subcard | wdmsplit slot/subcard/port}]

Displays the APS configuration for interfaces and groups.

Note Group names are case sensitive.


The following example shows how to display the switchover request status on an APS group:

Switch# show aps group blue

APS Group yellow:

architecture.: 1+1, remote prov: 1+1
span.........: end-to-end (client side y-cable)
direction....: prov: uni, current: uni, remote prov: uni
revertive....: no
  msg-channel..: auto (up on osc)
  created......: 15 hours, 1 minute
aps state....: associated (enabled)
request timer: holddown: 5000 ms, max: 15000 ms, count 2
  transmit k1k2: reverse-request, 1, 1, 1+1, bi
receive k1k2: forced-switch, 1, 1, 1+1, bi
  switched chan: 0
channel ( 0): Transparent4/0/0 (STANDBY - UP), Wave4/0 (UP)
               : channel request: lockout-of-protection
               : transmit request: lockout-of-protection
: receive request: no-request
channel ( 1): Transparent2/0/0 (ACTIVE - UP), Wave2/0 (UP)
: channel request: no-request
: switchover count: 0
: last switchover: never

Clearing Switchovers and Lockouts

A lockout stays in effect until the system reboots. A forced or manual switchover request stays in effect until the system reboots or a higher priority request preempts it. You can manually clear these requests from the CLI.

To clear an APS switchover or lockout request, use the following privileged EXEC command:

Command
Purpose

aps clear group-name

Clears APS switch request or lockout on an associated interface pair.


Example

The following example shows how to clear the requests on an associated interface pair using the default group name:

Switch# aps clear blue

Displaying Switchover and Lockout Clear Status

To display a pending switchover request, use the following command in privileged EXEC mode:

Command
Purpose

show aps [detail | group name | interface {transparent slot/subcard/0 | wavepatch slot/subcard/port | waveethernetphy slot/subcard | gigethernetphy slot/subcard}]

Displays the APS configuration for interfaces and groups.

Note Group names are case sensitive.


The following example shows how to display the lockout and switchover request status on an APS group:

Switch# show aps group blue

APS Group blue :

architecture.: 1+1, remote prov: 1+1
span.........: end-to-end (client side y-cable)
direction....: prov: uni, current: uni, remote prov: uni
revertive....: no
  msg-channel..: auto (up on osc)
  created......: 15 hours, 1 minute
aps state....: associated (enabled)
request timer: holddown: 5000 ms, max: 15000 ms, count 2
  transmit k1k2: reverse-request, 1, 1, 1+1, bi
receive k1k2: forced-switch, 1, 1, 1+1, bi
  switched chan: 0
channel ( 0): Transparent4/0/0 (STANDBY - UP), Wave4/0 (UP)
               : channel request: lockout-of-protection
               : transmit request: lockout-of-protection
: receive request: no-request
channel ( 1): Transparent2/0/0 (ACTIVE - UP), Wave2/0 (UP)
: channel request: no-request
: switchover count: 0
: last switchover: never

hometocprevnextglossaryfeedbacksearchhelp

Posted: Wed Apr 26 03:17:23 PDT 2006
All contents are Copyright © 1992--2006 Cisco Systems, Inc. All rights reserved.
Important Notices and Privacy Statement.