Trigger alarms of optical-layer service rerouting

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Optical-layer service rerouting can be triggered when alarms such as R_LOS, OTUk_LOF, and OTUk_LOM are reported only on OTU boards.

Other related questions:
Whether optical-layer ASON services are rerouted after an OBU board is removed and re-inserted
Question: If frontline engineers remove an OBU board from the OSN 6800 V100R007C02SPC200 in the optical-layer ASON network, and the corresponding FIU board does not report any alarms, will ASON services on the FIU board be rerouted? The OMS_TEL_DOWN alarm is generated on the TE link xxx as follows: OMS_TEL_DOWN CR start 2013-11-18 14:29:30+05:30 None NSA TEL Node=172.16.0.113,TE LinkID=0x8;,Sub-shelf=0,Board=2,Port=1,Error=0x2; Answer: In versions earlier than V100R007C00, after an OBU board is removed, ASON services on the corresponding FIU board are not rerouted. Since V100R007C00, the offline alarms of an OBU board are transferred to the corresponding FIU board. As a result, ASON services on the FIU board are rerouted. In conclusion, after an OBU board is removed from OSN 6800 V100R007C02SPC200, ASON services are rerouted. Suggestion and conclusion: By default, in versions earlier than V100R007C00, optical-layer ASON services are rerouted on the condition that the FIU board reports the MUT_LOS or BD_STATUS alarm. Since V100R007C00, optical-layer ASON services are also rerouted on the condition that boards on the line dimension report the BD_STATUS alarm. These boards can be OA boards, and multiplexer/demultiplexer boards.

Rerouting policies of diamond services
The rerouting policies for diamond services are described as follows: Permanent 1+1 protection: Rerouting is triggered when either the working or protection LSP is interrupted. Rerouting 1+1 protection: Rerouting is triggered only when both the working and protection LSPs are interrupted. Flex P&R: In this rerouting policy, P indicates the number of protection times. R indicates the number of rerouting times. Before P is used up, rerouting is triggered when either the working or protection trail becomes faulty. After P is used up, rerouting is triggered only when both the working and protection LSPs become faulty. After R is used up, rerouting is stopped. Non-rerouting 1+1 protection. No rerouting is triggered upon interruption of LSPs regardless of the working or protection LSP. On the NMS, the configuration of electrical-layer ASON services depends on the rerouting policies. On the page for creating electrical-layer diamond services, the services can be configured by setting the Trigger Condition parameter in Routing Attributes . There are four types of trigger conditions: 1. Rerouting is triggered when any LSP is interrupted. 2. Rerouting is triggered when both LSPs are interrupted. 3. Rerouting is not triggered. 4. Rerouting is triggered based on the flex P&R protection policy.

Precautions for setting rerouting trigger conditions on an ASON network
Rerouting trigger conditions are determined based on the number of available network resources and service importance. If there are sufficient resources or protected services are important, you can select the policy of triggering rerouting when any LSP fails. In this way, 1+1 protection is retained for services under SNCP protection or optical-layer associated services, and quick switching can be achieved upon a fault. Even if a rerouting failure occurs, the failure can be detected in a timely manner. If there are insufficient resources or the protected services are less important, you can select the policy of rerouting when both LSPs fail. In this way, the 1+1 protection provided for the services can survive only one fault. When both LSPs fail and service rerouting is triggered, the service will be interrupted for a short time (depending on the rerouting time), or be interrupted for a long time if rerouting fails.

Restrictions on a network for which both optical-layer ASON and electrical-layer ASON are configured
Optical-layer ASON and electrical-layer ASON can be configured on the same network but they cannot be configured on the same NE.

Solution for handling alarms when the OSN 8800 T16 with no SCC board serves as an optical-layer subrack
If the subrack has no CPU board, alarms are detected by the AUX board and reported to the SCC board in the master subrack. If the subrack has a CPU board, the AUX board transparently transmits alarms to the SCC board in the master subrack.

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