SYSTEM ADMINISTRATOR GUIDE     13/1543-CRA 119 1170/1-V1 Uen C    

Configuring APS MSP

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Disclaimer

The contents of this document are subject to revision without notice due to continued progress in methodology, design and manufacturing. Ericsson shall have no liability for any error or damage of any kind resulting from the use of this document.

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Contents

1Contents of this Document

2

Overview
2.1Requirements and Restrictions
2.2ASE Support for ATM APS
2.3Terminology

3

Configuration and Operations Tasks
3.1Configure an APS/MSP Group
3.2Configure the Working and Protect Ports
3.3Add Ports to an APS/MSP Group
3.4Manage Ports in an APS/MSP Group
3.5Change the Configuration of the Working and Protect Ports
3.6Replace a Traffic Card with Active Ports
3.7APS Operations

4

Configuration Examples
4.1Configure an APS/MSP Group
4.2Request a Lockout Switch
4.3Request a Forced Switch
4.4Request a Manual Switch
4.5CLIPS Configuration for MSP


1   Contents of this Document

This document describes how to configure, monitor, and administer Automatic Protection Switching (APS) and multiplex section protection (MSP) on Packet over SONET/SDH (POS) and second-generation Asynchronous Transfer Mode (ATM) OC ports.

2   Overview

Besides providing facility protection for traffic on the optical fiber ports, APS and MSP on the SmartEdge router provide equipment protection for the traffic card hosting the working port. If the traffic card fails and the protect port is on another traffic card, the SmartEdge OS switches the affected traffic to the protect port and allows the failed card to be serviced. APS and MSP also provide protection against line faults or failures for ATM OC ports.

The SmartEdge OS supports a subset of Synchronous Optical Network/Synchronous Digital Hierarchy (SONET/SDH) APS that is described in the Telcordia publication GR-253-CORE, SONET Transport Systems, Common Criteria, Section 5.3 and the SDH specification described in ITU-T Recommendation G..783. MSP is described in ITU-T Recommendation G.841. Annex B of ITU-T G.841 is not supported.

2.1   Requirements and Restrictions

Note:  
Configuring and enabling APS or MSP can have a negative impact on the performance of the SmartEdge router. Consult your support representative for more information.


 Caution! 
Risk of service disruption. When an APS or MSP working or protect port is removed (unconfigured) from an APS/MSP group, all sessions currently active on the ports are terminated. Only sessions configured on the working port can be brought back up as normal. To reduce the risk of service disruption beyond this temporary termination of sessions when you unconfigure a working or protect port from an APS/MSP group, do not remove either the working or protect port without first performing an APS/MSP aps switch force command on the active port to switch all sessions to the working port and locking out the protect port.

2.2   ASE Support for ATM APS

When the working and protect Automatic Protection Switching (APS) ATM ports are on different slots, and when traffic has to traverse the (Advanced Services Engine) ASE card for services such as Deep Packet Inspection (DPI), the ASE card replicates traffic going towards the ports in the APS/MSP group.

Use the show security asp command with the statistics keyword when examining the operating statistics of this feature.

2.2.1   Restrictions and Requirements

2.3   Terminology

The term APS configuration used in this document and other documents in the SmartEdge OS Library refers to the configuration of both APS and MSP groups.

The term traffic card refers to a SmartEdge 100 media interface card (MIC) or a SmartEdge 400 or SmartEdge 800 traffic card, unless otherwise noted.

Note:  
The traffic cards defined to be first-generation ATM-OC and second-generation ATM OC are listed in the Card Types section in Configuring Cards document.

3   Configuration and Operations Tasks

3.1   Configure an APS/MSP Group

To configure an APS/MSP group, perform the tasks described in Table 1; enter all commands in APS configuration mode, unless otherwise noted.

Table 1    Configure an APS Group

Step

Task

Root Command

Notes

1.

Create an APS/MSP group or select one for modification, and access APS configuration mode.

aps group

Enter this command in global configuration mode. Specify either ATM or POS as the group type. The default type is POS.

2.

Set the mode for the APS/MSP group

architecture 1+1

 

3.

Associate a description with the group.

description (APS)

 

4.

Optional. Specify the revertive switching algorithm and WTR interval.

revert

The default algorithm is nonrevertive.

3.2   Configure the Working and Protect Ports

Before you can assign a port as a working port in an APS/MSP group, the group must first be created. After the APS/MSP group is created, assign the working and protect ports to it in any order.

Note:  
ATM working ports may have their configurations changed at any time. ATM replicates the port configuration commands from the working port to the protect port, including the creation of ATM permanent virtual circuits (PVCs). This configuration can be applied to only ATM working ports; you can configure the port before adding it to a protect group, but not ATM virtual paths (VPs) or PVCs. After the port is added as a working port, the configuration is replicated to the protect port if it has been bound to the same APS/MSP group, or it is replicated after the protect port is added.

The following requirements apply to the port configuration:

3.3   Add Ports to an APS/MSP Group

To assign a port to an APS/MSP group, enter the aps command with either the working or protect keyword. Table 2 summarizes the task. You can add ports in any order. Enter the aps command in port configuration mode.

Table 2    Assign a Working Port and Protect Port

Task

Root Command

Notes

Assign the port to the APS/MSP group.

aps

Use either the working or protect keyword.


Ports must have the same type and framing. This command enables APS for SONET framed ports and MSP for SDH framed ports.

3.4   Manage Ports in an APS/MSP Group

To manage the ports in an APS group, perform one or more of the tasks described in Table 3. Enter all commands in port configuration mode unless otherwise noted.

Table 3    Manage Ports in an APS/MSP Group

Task

Root Command

Notes

Request a lockout of the protect port.

aps switch

Use the lockout keyword.

Request a high-priority (forced) switch of either the working or protect port.

aps switch

Use the forced keyword.

Request a low-priority (manual) switch of either the working or protect port.

aps switch

Use the manual keyword.

Remove a posted request.

aps switch

Use the no form to remove a posted request.

Remove (unconfigure) an ATM port from a group.

See Section 3.4.3

 

Remove (unconfigure) a POS port from a group.

See Section 3.4.1

 

Replace an ATM port in a group.

See Section 3.4.4.

 

Replace a POS port in a group.

See Section 3.4.2”.

 

Shut down an ATM port in a group.

See Section 3.4.5

 

Delete a group.

aps group

Enter this command in global configuration mode.


Use the no form to delete the group.

3.4.1   Delete (Unconfigure) a POS Port from an APS/MSP Group

Before you delete a POS port from an APS/MSP group (that is, before you change its configuration so that it no longer belongs to the group), enter the show aps command with the detail keyword (in any mode) to determine the status of the working and protect ports. To remove a POS port from an APS/MSP group, perform the tasks described in Table 4. Enter all commands in port configuration mode.


 Caution! 
Risk of service disruption. When you delete a POS working or protect port from an APS/MSP group, all sessions currently active on the port are terminated. Only sessions on the working port can be brought back up as normal. To reduce the risk of service disruption beyond this temporary termination of sessions when deleting a POS working or protect port from an APS/MSP group, perform one of the procedures provided in Table 4. Otherwise, the system might enter an undesirable state.
Note:  
Table 4 documents the procedures for configuring a POS port to remove it from an APS/MSP group only.

Table 4    Delete (Unconfigure) a POS Port from an APS/MSP Group

Port to Delete

Status of Traffic

Procedure

Protect

Active

1. Force all sessions on the protect port to the working port with the aps switch force command for the protect port.


2. Lock out the protect port with the aps switch lockout command for the protect port.


3. Remove the protect port with the no aps command for the protect port; the working port is not removed.

 

Standby

1. Lock out the protect port with the aps switch lockout command for the protect port.


2. Remove the protect port with the no aps command for the protect port; the working port is not removed.

Working

Active

1. Lock out the protect port with the aps switch lockout command for the protect port.


2. Remove the working port with the no aps command for the working port; the protect port is not removed.

 

Standby

1. Force all sessions on the protect port to the working port with the aps switch force command for the protect port.


2. Lock out the protect port with the aps switch lockout command for the protect port.


3. Remove the working port with the no aps command for the working port; the protect port is not removed.

3.4.2   Replace a POS Port in an APS/MSP Group

Before you replace a POS port in an APS/MSP group, enter the show aps command with the detail keyword (in any mode) to determine the traffic status of the working and protect ports; perform the tasks in Table 5.

Note:  
Table 5 documents the procedures for replacing a POS port in an APS/MSP group only.

Table 5    Replace a POS Port in an APS/MSP Group

Task

Root Command

Notes

Replace the working port:

1. Remove the working port from the group.

 

Select the task in Table 4 based on the traffic status of the port; the protect port is not removed. The ATM configuration under the port must be reapplied to the working port after the configuration is bound to the APS/MSP working group.

2. Assign the replacement port to the group as the working port.

aps

Use the working keyword.

Replace the protect port:

1. Remove the protect port from the group.

 

Select the procedure in Table 4 based on the traffic status of the port; the working port is not removed.

2. Assign the replacement port to the group as the protect port.

aps

Use the protect keyword.

3.4.3   Delete (Unconfigure) an ATM Port from an APS/MSP Group

To remove either the ATM working or protect port from an APS/MSP group (that is, to configure it so that it no longer belongs to the group), enter the no form of the aps command (in port configuration mode). When you delete an ATM working or protect port from an APS/MSP group, the system also removes the other port.

Note:  
When you remove an ATM working port from an APS/MSP group, all the VPs and PVCs are also removed.

3.4.4   Replace an ATM Port in an APS/MSP Group

To replace either the ATM working or protect port from an APS/MSP group, first delete the port from the group (that is, configure it so that it no longer belongs to the group): enter the no form of the aps command (in port configuration mode).

Then, add the new ATM working and protect ports to the group: enter the aps command (in port configuration mode). Either of these ports can be one of the ports you previously deleted.

Finally, reconfigure the ATM working port that you have added to the APS/MSP group; the system automatically replicates its configuration for the protect port.

Note:  
When you remove an ATM working port from an APS/MSP group, all the VPs and PVCs are also deleted.

3.4.5   Shut Down an ATM Port in an APS/MSP Group

To shut down an ATM working or protect port, perform the tasks described in Table 6.

Table 6    Shut Down an ATM Port in an APS/MSP Group

Port to Shut Down

Procedure

Protect

1. Verify the following conditions using the show aps command (in any mode) with the detail keyword for the protect port:


  • It is in standby mode.

  • It has no current or pending requests present.

  • It has no major or minor alarms.


2. If the port is in active mode, force all sessions on the protect port to the working port with the aps switch force command for the protect port.


3. Lock out the protect port with the aps switch lockout command for the protect port.(1)


4. Verify the protect port status using the show aps command with the detail keyword.


5. Shutdown the port, using the shutdown command (in port configuration mode)


6. Verify the working and protect port status using the show aps command with the detail keyword. The working port should be active and the protect port should be standby.

Working

Verify the following conditions using the show aps command (in any mode) with the detail keyword for the working port: It is in active mode.


  • It has no current or pending requests present.

  • It has no major or minor alarms.


2. Force all sessions on the working port to the protect port with the aps switch force command for the protect port.(2)


3. Verify the working port status using the show aps command with the detail keyword.


4. Shut down the working port, using the shutdown command.

(1)  An LOS condition detected on the working port has a lower priority than a lockout switch. Therefore, if an LOS occurs on the working port during this procedure, packets are lost.

(2)  An LOS condition detected on the protect port has a higher priority than a forced switch. Therefore, if an LOS occurs on the protect port during this procedure, traffic is switched back to the working port and packets are lost.


3.5   Change the Configuration of the Working and Protect Ports

You can change the configuration of a working port while it is a member of an APS/MSP group, but you must ensure that the configuration of the protect port is identical to that of the working port:

3.6   Replace a Traffic Card with Active Ports

If you must replace a POS or an ATM traffic card (remove it from the chassis and install a new traffic card) and that traffic card has one or more ports that are active in an APS/MSP group, perform the following procedure:

  1. Enter the show aps command with the detail keyword to determine which ports on the traffic card are active.
  2. For each active port on the affected traffic card, perform the following steps:
    1. Force all sessions on the active port to its standby port with the aps switch force command for the active port.
    2. Verify the change in status for the active and standby ports using the show aps command with the detail keyword.
    3. Shut down the previously active port, using the shutdown command.

       Caution! 

      If the working and protect ports are both on the same traffic card, this procedure is immaterial; all sessions are lost when the traffic card is removed from the chassis.

      Ensure that you enter the commit command after each configuration command and display the port APS/MSP status with the show aps command after each command is committed.
  3. Remove the traffic card from the chassis and install the new traffic card.
  4. Enter the no form of the aps switch force and shutdown commands for each port that you performed step 2.

3.7   APS Operations

To display Automatic Protection Switching (APS) information for one or more APS groups, perform the tasks listed in Table 7. Enter the show command in any mode.

Table 7    APS Operations

Task

Root Command

Display the status of one or more APS groups and their working and protect ports.

show aps

4   Configuration Examples

4.1   Configure an APS/MSP Group

The following example shows how to create the APS/MSP group lab48 with revertive switching and a WTR of 10 minutes, configure the ports on two OC-48c/STM-16c cards for the group, and add them to the group:

[local]Redback(config)#aps group lab48 pos
[local]Redback(config-aps)#architecture 1+1 bidirectional
[local]Redback(config-aps)#revert 10
[local]Redback(config-aps)#exit
[local]Redback(config)#port pos 1/1
[local]Redback(config-port)#encapsulation cisco-hdlc
[local]Redback(config-port)#aps working lab48
[local]Redback(config-port)#bind interface if-lab48 local
[local]Redback(config-port)#no shutdown
[local]Redback(config-port)#exit
[local]Redback(config)#port pos 2/1
[local]Redback(config-port)#encapsulation cisco-hdlc
[local]Redback(config-port)#aps protect lab48
[local]Redback(config-port)#no shutdown
[local]Redback(config-port)#exit

4.2   Request a Lockout Switch

The following example shows how to temporarily disable APS/MSP switching on port 3/1 (the protect port) by requesting a lockout:

[local]Redback(config)#port pos 3/1 
[local]Redback(config-port)#aps switch lockout 

The following example shows how to re-enable switching by removing the lockout request:

[local]Redback(config)#port pos 3/1 
[local]Redback(config-port)#no aps switch lockout 

4.3   Request a Forced Switch

The following example shows how to post a high-priority request to switch the sessions on working port 2/1 to the protect port:

[local]Redback(config)#port pos 2/1 
[local]Redback(config-port)#aps switch force 
Note:  
For the request to succeed, no higher-priority APS/MSP requests must be in effect.

The following example shows how to remove the high-priority request. Because the switching algorithm for the APS/MSP group is revertive, port 2/1 becomes the working port for the APS/MSP group after the WTR interval expires and no alarms have been posted against it:


[local]Redback(config)#port pos 2/1 
[local]Redback(config-port)#no aps switch force 

4.4   Request a Manual Switch

The following example shows how to post a low-priority request to switch the sessions on working port 2/1 to the protect port:

[local]Redback(config)#port pos 2/1 
[local]Redback(config-port)#aps switch manual 

For the request to succeed, no higher-priority APS/MSP requests must be in effect.

The following example shows how to remove the low-priority request. Because the switching algorithm for the APS/MSP group is revertive, port 2/1 becomes the working port for the APS/MSP group after the WTR interval expires and no alarms have been posted against it:

[local]Redback(config)#port pos 2/1 
[local]Redback(config-port)#no aps switch manual 

4.5   CLIPS Configuration for MSP

The following example shows how to create an MSP group for CLIPS over ATM POS:

[local]Redback(config)#aps group atm-msp atm
[local]Redback(config-aps)#revert 5
[local]Redback(config-aps)#architecture 1+1 bidirectional
[local]Redback(config-aps)#end
!...
[local]Redback(config)#port atm 4/1
[local]Redback(config-atm-oc)#framing sdh
[local]Redback(config-atm-oc)#no shutdown
[local]Redback(config-atm-oc)#aps working atm-msp
[local]Redback(config-atm-oc)#atm pvc 1 32 profile ubr encapsulation bridge1483
[local]Redback(config-atm-pvc)#service clips dhcp context local
[local]Redback(config-atm-pvc)#end
!...
[local]Redback(config)#port atm 11/1
[local]Redback(config-atm-oc)#framing sdh
[local]Redback(config-atm-oc)#no shutdown
[local]Redback(config-atm-oc)#aps protect atm-msp
[local]Redback(config-atm-oc)#end