Diamond WDM ASON Trail

Diamond WDM ASON trails have the best protection ability. When there are enough resources in the network, diamond WDM ASON trails provide a permanent 1+1 protection. The diamond WDM ASON trails are classified into ODU0, ODU1 trail, ODU2 trail and ODU3 trail. Diamond services are applicable to voice and data services, VIP private line, such as banking, security and aviation.

A diamond service is a service with 1+1 protection from the source node to the sink node. It is also called a 1+1 service. For a diamond service, there are two different LSPs available between the source node and the sink node. The two LSPs should be as separate as possible. One is the working LSP and the other is the protection LSP. The same service is transmitted to the working LSP and the protection LSP at the same time. If the working LSP is normal, the sink node receives the service from the working LSP; otherwise, from the protection LSP.

Figure 1 shows a diamond service.

Figure 1 Diamond Services

There are three types of diamond services.

Permanent 1+1 diamond service: rerouting is triggered once an LSP fails.
Rerouting 1+1 diamond service: rerouting is triggered only when both LSPs fail.
Non-rerouting diamond service: rerouting is never triggered.

Table 1 lists the attributes of the permanent 1+1 diamond service.

Table 2 lists the attributes of the rerouting 1+1 diamond service.

Table 3 lists the attributes of the non-rerouting 1+1 diamond service.

**Table 1** Attributes of the permanent 1+1 diamond services
Attribute	Permanent 1+1 Diamond Service
Requirements for creation	Sufficient non-protection resources are available between the source node and the sink node.
Protection type	During creation, diamond services generate the services that have the traditional WDM 1+1 protection attribute at the same time. Different ASON trails support different protection schemes. For WDM ASON OCh trail: supports intra-board 1+1 protection. (The protection schemes are OTU intra-board dual-feed and OTU+OLP/DCP dual-feed.) For WDM ASON ODUk trail: supports ODUk SNCP
Protection and restoration	If the resources are sufficient, two LSPs are always available for a permanent 1+1 diamond service. One is the active LSP and the other is the standby LSP. If the resources are not sufficient, one LSP can still be reserved for a permanent 1+1 diamond service to ensure the service survivability.
Rerouting	Supports setting the revertive mode. Supports setting the WTR time. Supports setting the scheduled reversion time. Supports setting revertive lockout. Supports rerouting lockout. Supports setting the rerouting priority. Supports setting the crankback times. Supports setting the trigger condition. Supports five rerouting policies: Use existing trails whenever possible Do not use existing trails whenever possible No rerouting constraint Use simulated section restoration Use preset restoration Supports rerouting triggered by SD. Supports setting the rerouting hold-off time.
Revertive	Supports Automatically Revertive, Non-Revertive, and Scheduled revertive. After the automatically revertive diamond service is rerouted, the service is automatically reverted to the original path if the fault in the original path is rectified. After the scheduled revertive diamond service is rerouted, the user can set the service to be reverted to the original path at a specific future time (ranging from 10 minutes to 30 days) on the NMS if the fault in the original path is rectified. After the non-revertive diamond service is rerouted, the service is not reverted to the original route after the fault is rectified.
Preset restoration trail	Supports setting two preset restoring trails. Preset restoration trails are preferred in rerouting.
Service Upgrade and Downgrade	Supports traditional 1+1 WDM trails upgrade to diamond WDM ASON trails. Supports diamond WDM ASON trails downgrade to traditional 1+1 WDM trails.
Service migration	Migration between optical-layer WDM ASON OCh trails is not supported. Supports migration between electrical-layer diamond WDM ASON trails and silver WDM ASON trails. Supports migration between electrical-layer diamond WDM ASON trails and copper WDM ASON trails.
Service switching	Supports manual switching.
Service optimization	Supports manual service optimization.

**Table 2** Attributes of the rerouting 1+1 diamond service
Attribute	Rerouting 1+1 Diamond Service
Requirements for creation	Sufficient non-protection resources are available between the source node and the sink node.
Protection type	During creation, diamond services generate the services that have the traditional WDM 1+1 protection attribute at the same time. Different ASON trails support different protection schemes. For WDM ASON OCh trail: supports intra-board 1+1 protection. (The protection schemes are OTU intra-board dual-feed and OTU+OLP/DCP dual-feed.) For WDM ASON ODUk trail: supports ODUk SNCP
Protection and restoration	When the standby LSP fails, services are not switched. Rerouting is not triggered. When the active LSP fails, services are switched to the standby LSP for transmission. Rerouting is not triggered. When both the active and the standby LSPs fail, rerouting is triggered to create an LSP to restore services.
Rerouting	Supports setting the revertive mode. Supports setting the WTR time. Supports setting the scheduled reversion time. Supports setting revertive lockout. Supports rerouting lockout. Supports setting the rerouting priority. Supports setting the crankback times. Supports setting the trigger condition. Supports five rerouting policies: Use existing trails whenever possible Do not use existing trails whenever possible No rerouting constraint Use simulated section restoration Use preset restoration Supports rerouting triggered by SD. Supports setting the rerouting hold-off time.
Revertive	Supports Automatically Revertive, Non-Revertive, and Scheduled revertive. After the automatically revertive diamond service is rerouted, the service is automatically reverted to the original path if the fault in the original path is rectified. After the scheduled revertive diamond service is rerouted, the user can set the service to be reverted to the original path at a specific future time (ranging from 10 minutes to 30 days) on the NMS if the fault in the original path is rectified. After the non-revertive diamond service is rerouted, the service is not reverted to the original route after the fault is rectified.
Preset restoration trail	Supports setting two preset restoring trails. Preset restoration trails are preferred in rerouting.
Service Upgrade and Downgrade	Supports traditional 1+1 WDM trails upgrade to diamond WDM ASON trails. Supports diamond WDM ASON trails downgrade to traditional 1+1 WDM trails.
Service migration	Migration between optical-layer WDM ASON OCh trails is not supported. Supports migration between electrical-layer diamond WDM ASON trails and silver WDM ASON trails. Supports migration between electrical-layer diamond WDM ASON trails and copper WDM ASON trails.
Service switching	Supports manual switching.
Service optimization	Supports manual service optimization.

**Table 3** Attributes of the non-rerouting 1+1 diamond service
Attribute	Non-rerouting 1+1 diamond service
Requirements for creation	Sufficient non-protection resources are available between the source node and the sink node.
Protection type	During creation, diamond services generate the services that have the traditional WDM 1+1 protection attribute at the same time. Different ASON trails support different protection schemes. For WDM ASON OCh trail: supports intra-board 1+1 protection. (The protection schemes are OTU intra-board dual-feed and OTU+OLP/DCP dual-feed.) For WDM ASON ODUk trail: supports ODUk SNCP
Protection and restoration	When the active LSP fails, services are switched to the standby LSP for transmission. Rerouting is not triggered. When the standby LSP fails, services are not switched. Rerouting is not triggered. When both the active and the standby LSPs fail, rerouting is not triggered.
Service Upgrade and Downgrade	Supports traditional 1+1 WDM trails upgrade to diamond WDM ASON trails. Supports diamond WDM ASON trails downgrade to traditional 1+1 WDM trails.
Service migration	Migration between optical-layer WDM ASON OCh trails is not supported. Supports migration between electrical-layer diamond WDM ASON trails and silver WDM ASON trails. Supports migration between electrical-layer diamond WDM ASON trails and copper WDM ASON trails.
Service switching	Supports manual switching.
Service optimization	Supports manual service optimization.

NOTE:

When diamond ODUk ASON WDM trails are created, setting the SNC/N(PM) and SNC/S(TCM) modes is supported.

When k is 0, only the non-intrusive monitoring (SNC/N) is supported. When k is 1 or 2, the sub-layer monitoring (SNC/S) and non-intrusive monitoring (SNC/N) are supported.

When the SNCP type is set as sub-layer monitoring, the Web LCT supports setting TCM layers (TCM = 1-5).

Traditional services in the SNC/I, SNC/N, and SNC/S modes can be upgraded into diamond ASON services. After rerouting, the SNC mode of services in the SNC/I and SNC/N(TCM) modes is changed into SNC/N(PM).