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This chapter tells you how to configure SONET automatic protection switching (APS) for the OC-12 POS line card and the ChOC-12 line card.
To configure redundancy to enable SONET APS, perform the following steps:
Router(config)# redundancy
Step 2 Associate two cards as a redundant pair. You must specify a card installed in an odd slot number as the first member of a redundant pair; the second card must be installed in the even numbered slot to its right.
Router(config-r)# associate slot 5 6
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Tips When configuring APS between a Cisco 10000 and a Cisco 12000, configure the Cisco 12000 to use 1+1 unidirectional, non-revertive APS. |
When you associate slots, the software pairs an odd-numbered slot with the next higher even-numbered slot:
Figure 10-1 shows the redundant slot pairings.
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Note After you configure redundancy, the software treats the pair as if it occupied a single slot. The interface slot number is always the odd number of the redundant pair. For example, for the redundant pair occupying slots 5 and 6, the command show interface pos 5/0/0 refers to the active card (even if the active card occupies slot 6). |
To disable redundant operation, use the no form of the associate slot command. For example:
Router(config-r)# no associate slot 3
If the redundant configuration is disabled, the software modifies the running configuration in the following ways:
1. The software removes all APS configuration information.
2. The software creates two configurations, one for each card (Table 10-1).
| Redundancy On | After Redundancy Is Turned Off |
|---|---|
card 5/0 1oc12pos-1 card 6/0 1oc12pos-1 ! redundancy associate slot 5 6 ! interface POS5/0/0 ip address 5.5.5.5 255.255.255.0 no ip directed-broadcast ip mtu 1500 loopback internal no keepalive aps mode linear 1+1 nonreverting unidirectional aps signal-fail BER threshold 3 aps signal-degrade BER threshold 5 crc 32 clock source internal pos scramble-atm pos threshold sd-ber 5 pos flag c2 0 pos flag j0 0 | card 5/0 1oc12pos-1 card 6/0 1oc12pos-1 ! interface POS5/0/0 ip address 5.5.5.5 255.255.255.0 no ip directed-broadcast ip mtu 1500 loopback internal no keepalive crc 32 clock source internal pos scramble-atm pos threshold sd-ber 5 pos flag c2 0 pos flag j0 0 ! interface POS6/0/0 ip address 6.6.6.6 255.255.255.0 no ip directed-broadcast ip mtu 1500 no ip route-cache cef no keepalive ... |
This section lists commands you can use to customize APS configuration or find out information about its status.
Threshold commands allow you to specify criteria that trigger a cutover. In addition to the criteria set by these commands, cutovers are triggered by Section Loss of Signal (SLOS) critical alarms, Section Loss of Frame (SLOF) critical alarms, and Line Alarm Indicate Signal (LAIS) major alarms.
Use the aps signal-degrade BER threshold command to modify the bit error rate threshold that, if exceeded, triggers an APS cutover.
aps signal-degrade BER threshold value[no]aps signal-degrade
Where value can be in the range of 10-5 to 10-9. Enter this value as a single digit between 5 and 9.
The default signal degrade BER threshold value is 10-6.
Use the no form of the command to return the threshold value to its default.
In the following example, the threshold value is set to 10-8:
Router(config)# interface pos 8/0/0 Router(config-if)# aps signal-degrade BER threshold 8
Use the aps signal-fail BER threshold command to modify the bit error rate threshold that, if exceeded, causes an APS cutover.
aps signal-fail BER threshold value[no]aps signal-degrade
Where value can be in the range of 10-3 to 10-5. Enter this value as a single digit between 3 and 5.
The default signal fail BER threshold value is 10-3.
Use the no form of the command to return the threshold value to its default.
In the following example, the threshold value is set to 10-4:
Router(config)# interface pos 8/0/0 Router(config-if)# aps signal-fail BER threshold 4
The show aps command reports on the status of the APS-configured slot. In the following example, slot 5 contains the primary (also called working) card and slot 6 contains the secondary (also called protected) card. The port status for the working (w) card and the protected (p) card is good.
Router# show aps
POS5/0/0:APS Lin NR Uni, Failure channel:Protection
Active Channel:POS5/0/0
Port stat (w,p):(Good, Good)
Posted: Tue Oct 3 09:51:21 PDT 2000
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