Gold service protection on ASON networks


1. Principles of gold services
Gold services use MS link resources. When a fiber cut occurs for the first time, MSP switching is triggered. If the MS protection switching fails, rerouting restoration protection will be triggered. Establishing a service will fail if no sufficient MS link is available. In addition, service establishment complies with the timeslot consistency principle. During MSP switching upon the first fiber cut, signals do not follow the actual path of a gold service. An MSP switching failure will trigger rerouting. During rerouting, MS links are preferentially used. If no such resource is available or MS links are insufficient, an unprotected link will be used to ensure that the service is not interrupted. In this case, the service is in degraded state. If the MSP link recovers, the service will not be automatically switched back to the MS link. The MS link will be used for the next rerouting if possible.
2. Features of gold services
MS links are used for establishing services, and service establishment complies with the timeslot consistency principle.
Static services that completely use MS links can be upgraded to gold services.
Static services that partially use MS links can be upgraded to gold services. After the upgrade, however, the protection status of the services is "Degrade".
Gold services can be downgraded to static services.
MSP switching is triggered upon the first fiber cut.
Rerouting restoration protection is triggered if MSP switching fails.
During rerouting, if links with consistent timeslots are unavailable, links with inconsistent timeslots are used; or if MSP links are unavailable, links without protection are used.
Lockout of rerouting is supported.
Service path optimization is supported.
Service names can be modified.
3. MSP types supported by gold services
1:1 linear MSP
Two-fiber bidirectional MSP ring
Four-fiber bidirectional MSP ring
4. Restrictions and limitations
During service creation, only loose cross-ring nodes can be specified. If a non-cross-ring node needs to be specified, the timeslot must be specified.
Gold services cannot be associated.
Failure nodes or links of the original trails cannot be excluded during rerouting.

Other related questions:
Types of ASON services
Question: What are the types of ASON services? Answer: Diamond service: important services that need to be kept for a long time and allow only transient interruptions, such as private lines for banks, securities, and important government sectors. Gold service: services that have strict requirements on real-time processing, latency, and transient service interruption time, such as 2M and 3G voice services, and VIP customer services. Silver service: services with unstable, burst, and heavy traffic, and that do not require real-time processing, such as data private line services, cell Internet access services, and cable TV services. Copper service: temporary services. The impact is small even if such a service is interrupted. Summary and Suggestion: An important feature of ASON is the survival against multiple faults. The survivability requirements are as follows: A diamond service can be rerouted to a new trail for at least once after its working or protection trail becomes faulty. A gold service can undergo at least one protection switching and can be rerouted and restored for at least once. A silver service can be rerouted and restored for at least once. For the first or last node of a service, when a link that carries the maximum service bandwidth becomes faulty for the first time, the impaired service can be restored to another fiber of the node. It is recommended that the services be converged into VC-4 services outside ASON NEs if possible. If tunnel services are required, gold tunnels are preferentially selected. Silver tunnel is the second choice. In this case, you need to create two silver tunnels with separate routes, and configure lower-order SNCP services for dual-feeding and selective receiving of the two silver tunnels.

ASON service SLA
ASON service SLAs are classified into diamond, silver, and copper. The service protection policies vary according to service SLAs. Diamond services have the highest priority in the system. That is, the system ensures the normal transmission of diamond services with preference. Silver services have a priority higher than copper services but lower than diamond services.

Service association in ASON
Service association is intended for some important services for which protection is required. Different from diamond services, service association allows service add and drop at different sites. Associated silver services with the same source support sharing of associated trails. When one of the associated services is interrupted, the rerouted trail will separate from the associated trail to ensure that the two trails do not completely overlap only when the trail sharing is disabled.

Impact of enabling ASON on live-network services
Enabling ASON only does not affect live-network services. Node IDs, however, must be set before you enable ASON. If you set node IDs after enabling ASON, NEs will be reset and live-network services will be affected.

System processing when a fault occurs during the WTR time on an ASON network?
When a fault occurs during the WTR time, how the system processes a service is related to the service SLA but not related to whether the automatic reversion time is set. For example, if the service is under diamond rerouting 1+1 protection and the protection trail is faulty during the WTR time, the ASON software considers that both the working and protection trails are faulty and therefore computes a new route according to the rerouting 1+1 protection mechanism. If the service is under diamond non-rerouting 1+1 protection, when the preceding condition occurs, the service is directly interrupted according to the non-rerouting 1+1 protection mechanism.

If you have more questions, you can seek help from following ways:
To iKnow To Live Chat
Scroll to top