ASON Management

ASON Management

An automatically switched optical network (ASON) is a new-generation optical transmission network.

With integration of SONET/SDH functionality, effective IP technology, large-capacity WDM/OTN, and revolutionary network control software, ASON lays a foundation for flexible and scalable next generation optical networks, which are easy to operate and manage, and less expensive to operate.

Introducing ASON into WDM networks brings the following benefits:

High reliability: Protection and restoration together improve network reliability and service security.

Easy to use: Network resources and topologies are easy to discover and end-to-end services can be quickly created.

Easy to manage: Trail resources are manageable and predictable, and services can be automatically reverted to their original trails.

Investment saving: A mesh network ensures higher resource usage and enables quick expansion (plug-and-play).

New service types: Service level agreement (SLA) ensures differentiated services.

WDM/OTN equipment is an effective service carrier. However, only the capability of carrying services (on the transport plane) does not qualify WDM/OTN equipment as advanced and future-oriented equipment, which also requires outstanding performance in bandwidth usage, flexibility, manageability, maintainability, reliability, and protection capability. It has become a trend to implement a control plane over the transport plane of the WDM/OTN equipment.

The limitations on the WDM/OTN equipment are removed after the ASON technology is implemented on the WDM/OTN equipment. Because of the ASON technology, the WDM/OTN equipment features high reliability, flexibility, bandwidth utilization, maintainability, and manageability and supports different service levels and quick deployment of services. Further, the operability of a WDM/OTN network is highly improved because of the features supported by the ASON technology, such as automatic discovery of resources, traffic engineering, dynamic bandwidth adjustment, and interconnection and communication technologies.

Background and Advantages

Compared with the WDM network, the transmission network that applies the new ASON technology shows advantages in service configuration, bandwidth utilization and protection schemes.

In the traditional transmission network, the WDM transmission equipment functions as fibers. Currently, the WDM transmission equipment also carries services. As a result, more requirements are for the operability of the WDM equipment. The traditional network has the following problems:

The service configuration is complex and capacity expansion or service provision takes a long period.

The bandwidth utilization is of a low rate and low efficiency. In a ring network, half of the bandwidth should be reserved.

Just a few protection schemes are available and the performance of self-healing protection is poor.

The ASON has been developed to solve these problems. This technology involves signaling switching and a control plane to enhance its network connection management and recovery capability. It supports end-to-end service configuration and the service level agreement (SLA).

Service Configuration

Traditional WDM networks are generally chains and rings. The trails and timeslots of their services are manually configured ring by ring and point by point, which consumes a lot of time and effort. As networks become increasingly large and complicated, this service configuration mode cannot meet the rapidly increasing user demands.

The ASON successfully solves this problem by end-to-end service configuration. To configure a service, you only need to specify its source node, sink node, bandwidth requirement and protection type; the network automatically performs the required operations.

Bandwidth Utilization

Traditional WDM optical transmission networks have a large amount of resources reserved and lack advanced service protection, and the restore and routing functions. In contrast, with the routing function the ASON can provide protection by reserving fewer resources, thus increasing network resource utilization.

Protection and Restoration

Chain and ring are the main topologies used in a traditional WDM network. Optical line protection or board-level protection are the main protection schemes for the services. In ASON, mesh is the main topology. Besides protections, the dynamic restoring function is available to restore the services dynamically. In addition, when there are multiple failures in a network, the services can be restored as many as possible.

According to the difference in the service restoration time, multiple service types are defined in ASON networks to meet different customer requirements.

Basic Concepts of ASON

The basic concepts related to the ASON are the label switched path (LSP) and rerouting.

ASON

ASON is a new generation optical network that has the following features:

Customers launch a service request dynamically.

Routes are selected automatically.

Signaling controls the creation and removal of connections.

Network connections are automatically and dynamically completed.

Switching and transmission are integrated into one system.

LSP

Label switched path (LSP) is the path ASON services pass through. In an ASON, to create ASON services is to create LSPs. On U2000, LSP is also called ASON Trail.

WDM ASON Trail

WDM ASON Trail is classified into WDM ASON OCh Trail and WDM ASON ODUk Trail. See Figure 1.

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The WDM ASON OCh trail can be created when there are sufficient OCh TE link resources.

The WDM ASON ODUk trail can be created when there are sufficient TE link resources where the payload type is ODUk.

Figure 1 WDM ASON Trail

NOTE:

The OptiX OSN 8800 does not support the WDM ASON client route.

Rerouting

Rerouting is a means of resuming services. For a non-revertive service, when an LSP is disconnected, the source node queries and finds the best route to resume services. Then, the initial node creates a new LSP to transmit the service. After creating a new LSP, the source node deletes the original LSP.

NOTE:

After a revertive service is rerouted, the original LSP is not deleted.

NOTE:

For more information on service restoration, refer to ASON Network Protection and Restoration.

Rerouting Lockout

In some cases, rerouting is not required after failure of LSP. Then you need to set rerouting lockout.

Rerouting Policy

Diamond and silver services all support the several rerouting polices. You can flexibly choose a rerouting policy and properly use network resources according to different network conditions.

Overlapping policy

During rerouting, the route of the new LSP overlaps the original route whenever possible. This policy helps save network resources. When bandwidth resources are insufficient, the service gets more chances to reroute successfully.

Separating policy

During rerouting, the route of the new LSP is separated from the original route whenever possible. This policy is applicable to a network with sufficient link resources.

Best route policy

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During rerouting, the best route is computed for the new LSP. Whether the new or old route resources are utilized again is not considered. This policy chooses a route with the minimum cost as the new route after rerouting according to network conditions.

Simulated span restoration policy

During rerouting, the services must reuse the original routes without involving faulty spans. End-to-end rerouting is enabled only when rerouting on the faulty spans fails, and thus service route can be controlled and managed more easily.

NOTE:

The rerouting policy can be set on the U2000 according to actual conditions.

SLA Classification of Services

The ASON network can provide services of different QoS to different clients.

The service level agreement (SLA) is used to classify services according to the service protection, as listed in Table 1.

Table 1 Service level (WDM Service)

Service Protection and

Restoration Scheme

Implementation Means

Switching Time

Rerouting Time Bandwidth Utilization

Diamond service

Protection and restoration

intra-board 1+1 protection, ODUk SNCP and rerouting

Less than 50 ms

The rerouting time varies with the network size, capacity and service types.

33% (1+1 protection. One restoration trail is reserved.)

Silver service

Restoration Rerouting - 75% (Dynamic rerouting and shared mesh protection, resulting in high utilization of resources. Consider a four-dimensional node as an example. The resource utilization is 75% in the case of a single fiber break.)

Copper service

No protectionNo restoration

- - - 100% (No protection. Theoretically, the resources can be fully occupied.)

Table 2 lists details of the TE links used by ASON services.

Table 2 TE links used by WDM ASON trails (WDM Service)

Service Level Working Resource of TE Link

Protection Resource of TE Link

Non-Protection Resource of TE Link

Diamond service Not used Not used Used

Silver service Not used Not used Used

Copper service Not used Not used Used

Parent topic: OTN ASON Feature

Diamond WDM ASON Trail

Diamond WDM ASON trails have the best protection ability. When there are enough resources on the network, diamond WDM ASON trails provide a permanent 1+1 protection for the WDM ASON diamond ODUk 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 proper, the sink node receives the service from the working LSP; otherwise, from the protection LSP.

NOTE: The optical-layer diamond service specification is removed because of the following factors: (the optical-layer diamond service solution will be replaced by the associated silver ASON service solution)

When two LSPs share the same OTU, they use the same wavelength. Therefore, rerouting of the two LSPs also must use the same wavelength, which makes finding a route very difficult.

Service switching within 50 ms cannot be guaranteed when 40G OTUs are used because the TDC adjustment requires more than 50 ms.

When the service runs on the working LSP, the service performance monitoring is not available for the backup LSP. This cannot ensure that the backup LSP is in normal state or available, which will impair the service SLA.

Figure 1 shows a diamond service.

Figure 1 Diamond Services

NOTE:

In the creation of diamond services, two LSPs are generated, which have the feature of 1+1 protection for traditional WDM services. The working trail corresponds to the working LSP, and the protection trail corresponds to the protection LSP. When the working trail fails, the protection switching is performed through the traditional WDM 1+1 protection and then a new LSP is created through rerouting.

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 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 valid LSP can still be reserved

for a permanent 1+1 diamond service to ensure the service survivability. The other LSP is also available but may be invalid.

Rerouting Supports rerouting lockout.

Supports rerouting priority. Supports several rerouting policies:

Use existing trails whenever possible

Do not use existing trails whenever possible

Best route Simulated span restoration policy

Revertive Supports reverting to the previous route.

Preset restoring trail Supports setting the preset restoring trail.

Service conversion Supports conversion between diamond services and traditional 1+1 services.

Supports conversion between diamond WDM ASON trails and silver WDM ASON trails.

Supports conversion between 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.



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 a new LSP to restore services.




Supports rerouting priority.

Supports several rerouting policies:

Use existing trails whenever possible Do not use existing trails whenever possible

Best route


Revertive Supports reverting to the previous route.

Preset restoring trail

Supports setting the preset restoring trail.





Service optimization

Supports manual service optimization.

Table 3 Attributes of the non-rerouting 1+1 diamond service

Attribute Non-rerouting 1+1 diamond service







When both the active and the standby LSPs fail, rerouting is not triggered.

Preset restoring trail

Supports setting the preset restoring trail.








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(PM)) is supported. When k is 1, 2 or 3, the sub-layer monitoring (SNC/S(TCM)) and non-intrusive monitoring (SNC/N(PM)) are supported.

When the SNCP type is set as sub-layer monitoring, the U2000 supports setting TCM layers (TCM=1–5).

Traditional services in SNC/I, SNC/N, and SNC/S protection modes can be upgraded into diamond ASON services with the protection modes unchanged. After rerouting, SNC protection for services in the SNC/I and SNC/N(TCM) protection modes changes into SNC/N(PM).

Silver WDM ASON Trail

Silver WDM ASON services, including WDM ASON OCh trails, ODUk trails, the revertive time is several seconds. The silver level service is suitable for those data or internet services that have low real-time requirement.

Silver services refer to the service connections from the source node to the destination node with the rerouting protection attribute. They are also called rerouting services. If the LSP of the silver services fails, rerouting is repeatedly initiated to restore the services until the rerouting is successful. The silver services compute the restoration tail in real time, and thus no resource needs to be reserved in advance. Hence, the bandwidth utilization is high. If there are not enough resources, the services may be interrupted.

As shown in Figure 1, A-B-G-H-I is a silver service trail. If the fiber between B and G is cut, the ASON triggers rerouting from A to create a new LSP that does not pass the cut fiber. Hence, services are protected.

Figure 1 A silver service

Table 1 lists the attributes of silver services.

Table 1 Attributes of silver services

Attribute Silver Services


Service restoration When the original LSP fails, rerouting is triggered to create a new LSP to restore services.

Rerouting Supports rerouting lockout. Supports rerouting priority.

Supports several rerouting policies:

Use existing trails whenever possible

Do not use existing trails whenever possible Best route


Revertive Services in the WDM ASON ODUk, OCh trail support reverting to the previous route manually or automatically.


Service migration Supports migration between silver services and traditional unprotected services without affecting them.

Supports migration between silver services and diamond services.

Supports migration between silver services and copper services.

NOTE:



In the case of the WDM ASON OCh trails, the conversion between the silver and diamond or copper is not supported.


Service association Supports service association.

Parent topic: OTN ASON Feature

Copper WDM ASON Trail

The copper services are seldom used. Generally, temporary services, such as the abrupt services in holidays, are configured as copper services. The copper WDM ASON trails are classified into OCh trail, ODUk trail.

Copper services are also called non-protection services. If an LSP fails, services do not reroute and are interrupted. Table 1 lists the attributes of copper services.

Table 1 Attributes of copper services

Attribute Silver Service



Service restoration Does not support rerouting.

Service migration Supports migration between copper services and traditional services.

Supports migration between copper services and diamond services.

Supports migration between copper services and silver services.NOTE:

In the case of the WDM ASON OCh trails, the conversion between the copper and diamond or silver levels is not supported.



Mesh Networking Protection and Restoration

The ASON provides mesh networking protection to enhance service survivability and network security.

The ASON provides mesh networking protection to enhance service survivability and network security.

As a main networking mode of ASON, mesh features high flexibility and scalability. Compared with the traditional SDH networking mode, the mesh networking does not need to reserve 50% bandwidth. Thus, it can save bandwidth resources to satisfy increasingly large bandwidth demand. In addition, this networking mode also provides more than one recovery route for each services so it can best utilize the network resources and enhance the network security.

As shown in Figure 1, when the C-G link fails, to restore the service, the network calculates another route from D to H and creates a new LSP to transmit the service.

Figure 1 Trail restoration

SLA Classification of Services

The ASON network can provide services of different QoS to different clients.

The service level agreement (SLA) is used to classify services according to the service protection, as listed in Table 1.

Table 1 Service level (SDH Service)

Service Protection and Restoration Scheme

Implementation Means Switching and Rerouting Time

Diamond service

Protection and restoration SNCP and rerouting Switching time < 50 msRerouting time < 2s

Gold service Protection and restoration MSP and rerouting Switching time < 50 msRerouting time < 2s

Silver service

Restoration Rerouting Rerouting time < 2s

Table 1 Service level (SDH Service)

Service Protection and Restoration Scheme

Implementation Means Switching and Rerouting Time

Copper service

No protectionNo restoration

- -

Iron service Preemptable MSP -

Table 2 lists details of the TE links used by ASON services.

Table 2 TE links used by ASON services

Service Level Working Resource of

TE Link



Diamond service

Service creation Not used Not used Used

Service rerouting Not used Used when the resource is not enough

Used with the priority

Service optimization Not used Not used Used

Gold service Service creation Used with the priority

Not used Used when the resource is not enough

Service rerouting Used with the priority

Used when the resource is not enough

Used when the resource is not enough

Service optimization Used with the priority

Not used Used when the resource is not enough

Silver service


Service rerouting Not used Used when the resource is not enough

Used with the priority


Copper service



Iron service Service creation Not used Used with the priority Used when the resource is not

Table 2 TE links used by ASON services

Service Level Working Resource of

TE Link



enough

Service optimization Not used Used with the priority Used when the resource is not enough

Diamond Services

Diamond services have the best protection ability. When there are enough resources in the network, diamond services provide a permanent 1+1 protection. 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.




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.


Supports rerouting priority. Supports three rerouting policies:


Best route

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.

NOTE:

The original route is the route before rerouting but may not be the original route set up when the ASON trail is created.

Service migration Supports migration between diamond services and permanent SNCP connections.

Supports migration between diamond services and gold services. Supports migration between diamond services and silver services.

Supports migration between diamond services and copper services.


Service optimization Supports service optimization.

Service association Does not support service association.

ASON server trail Support diamond ASON server trails.



Alarms to trigger rerouting R_LOS, R_LOF, B2_EXC, B2_SD, MS_AIS, MS_RDI, AU_AIS, B3_EXC (can be set), B3_SD (can be set)

Table 2 Attributes of the rerouting 1+1 diamond service

Attribute Rerouting 1+1 Diamond Service


Sufficient non-protection resources are available between the source node and the sink node




When both the active and the standby LSPs fail, rerouting is triggered to create a new LSP to restore services.



Supports three rerouting policies: Use existing trails whenever possible

Do not use existing trails whenever possible Best route

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.

NOTE:



Supports migration between diamond services and gold services.

Supports migration between diamond services and silver services. Supports migration between diamond services and copper services.







Alarms to trigger rerouting

R_LOS, R_LOF, B2_EXC, B2_SD, MS_AIS, MS_RDI, AU_AIS, B3_EXC (can be set), B3_SD (can be set)




Sufficient non-protection resources are available between the source node and the sink node




When both the active and the standby LSPs fail, rerouting is not triggered.


Supports migration between diamond services and gold services.

Supports migration between diamond services and silver services. Supports migration between diamond services and copper services.





Gold Services

Gold services are applicable to voice and significant data services. Compared with diamond services, gold services have greater bandwidth utilization.

A gold service needs only one LSP. This LSP must use working resource of TE links or non-protection resource of TE links. When a fiber on the path of a gold service is cut, the ASON triggers MSP switching to protect the service at first. If the multiplex section protection fails, the ASON triggers rerouting to restore the service.

As shown in Figure 1, a gold service can be configured from A to I.

Figure 1 Gold services

Table 1 lists the attributes of gold services.

Table 1 Attributes of gold services

Attribute Gold Service

Requirements for creation Sufficient working resources or non-protection resources are available between the source node and the sink node.

Multiplex section protection Supports using the working resources of a 1:1 linear multiplex section protection chain to create gold services.

Supports using the working resources of a 1+1 linear multiplex section protection chain to create gold services.

Supports using the working resources of a 1:N linear multiplex section protection chain to create gold services.

Supports using the working resources of a two-fiber bidirectional multiplex section protection ring to create gold services.

Supports using the working resources of a four-fiber bidirectional multiplex section protection ring to create gold services.

Protection and restoration When a fiber is cut for the first time, MS switching is performed to protect services. When MS switching fails, rerouting is then triggered to restore services.



Supports three rerouting policies:


Best route

Table 1 Attributes of gold services

Attribute Gold Service

Revertive Supports Automatically Revertive, Non-Revertive, and Scheduled revertive. After the automatically revertive gold service is rerouted, the


After the scheduled revertive gold 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 gold service is rerouted, the service is not reverted to the original route after the fault is rectified.

NOTE:



Service migration Supports migration between permanent connections and gold services.

Supports migration between gold services and diamond services.

Supports migration between gold services and silver services.

Supports migration between gold services and copper services.



ASON server trail Supports gold ASON server trails.


Silver Services

Silver services, the revertive time is hundreds of milliseconds to several seconds. The silver level service is suitable for those data or internet services that have low real-time requirement.

Silver services are also called rerouting services. When an LSP failure, the ASON triggers rerouting to restore the service. If there are not enough resources, service may be interrupted.

As shown in Figure 1, A-B-G-H-I is a silver service trail. If the fiber between B and G is cut, the ASON triggers rerouting from A to create a new LSP that does not pass the cut fiber. Hence, services are protected.

Figure 1 A silver service

Table 1 lists the attributes of silver services.




Service restoration When the original LSP fails, rerouting is triggered to create a new LSP to restore services.



Supports three rerouting policies: Use existing trails whenever possible

Do not use existing trails whenever possible

Best route

Revertive Supports Automatically Revertive, Non-Revertive, and Scheduled revertive. After the automatically revertive silver service is rerouted, the


After the scheduled revertive silver 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 silver service is rerouted, the service is not



reverted to the original route after the fault is rectified.NOTE:



Shared mesh restoration trail Supports setting the shared mesh restoration trial for revertive silver trials.

Service migration Supports migration between permanent connections and silver services.

Supports migration between diamond services and silver services. Supports migration between gold services and silver services.

Supports migration between silver services and copper services.



ASON server trail Supports silver ASON server trails.


Copper Services

The copper services are seldom used. Generally, temporary services, such as the abrupt services in holidays, are configured as copper services.

Copper services are also called non-protection services. If an LSP fails, services do not reroute and are interrupted. Table 1 lists the attributes of copper services.






Service migration Supports migration between copper services and traditional services.



Supports migration between copper services and diamond services. Supports migration between copper services and gold services.

Supports migration between copper services and silver services.



ASON server trail Supports ASON server trails.

Iron Services

The iron services are also seldom used. Generally, temporary services are configured as iron services. For example, when service volume soars, during holidays, the services can be configured as iron services to fully use the bandwidth resources.

An iron service is also called a preemptable service. Iron services apply non-protection resources or protection resources of the TE link to create LSPs. When an LSP fails, services are interrupted and rerouting is not triggered.

When the iron service uses the protection resources of the TE link, if the MS switching occurs, the iron service is preempted and the service is interrupted. After the MS is recovered, the iron service is restored. The interruption, preemption and restoration of the iron service are all reported to the U2000.

When the iron service uses the non-protection resources, if the network resources are insufficient, the iron service may be preempted by the rerouted silver service or diamond service. Thus, the service is interrupted.

Table 1 lists the attributes of iron service.

Table 1 Attributes of iron services

Attribute Iron Service


Sufficient protection resources or non-protection resources are available between the source node and the sink node.

Multiplex section protection

To create iron services, the following resources can be used:

Protection resources of 1:1 linear MSP Protection resources of 1:N linear MSP

Protection resources of two-fiber bidirectional MSP

Protection resources of four-fiber bidirectional MSP


Service migration Supports migration between iron services and extra permanent connections.

Table 1 Attributes of iron services

Attribute Iron Service


Supports service optimization.

Tunnels

Tunnels are mainly used to carry VC-12 or VC-3 services. Tunnels are also called as ASON server trails.

When lower order services are to be created, first create a VC-4 tunnel. The protection level for the tunnel can be diamond, gold, silver or copper. Then, use the management system to complete the configuration of the lower order service. See Figure 1.

Figure 1 Tunnel

The configuration of a tunnel is different from that of the above-mentioned service types. Its cross-connection from the tributary board to the line board can only be configured manually. As shown in Figure 2, there is a tunnel between NE1 and NE2 which can be a diamond ASON server trail, a gold ASON server trail, silver ASON server trail or copper ASON server trail. During service creation, the ASON automatically chooses the line boards of NE1 and NE2 and the timeslots of the line boards.

After creating tunnels, you must manually create and delete the lower order cross-connection from the tributary board to the line board. During rerouting or optimization of the tunnels, however, the cross-connections at the source and sink nodes automatically switch to the new ports.

NOTE:

In addition, the end-to-end tunnel and lower order service can be created.

Figure 2 Lower cross-connection

Table 1 lists the attributes of tunnels.

Table 1 Attributes of tunnels

Attribute Gold Tunnel Silver Tunnel Copper Tunnel

Requirements for creation Same as gold services Same as silver services Same as copper services

Service restoration Same as gold services Same as silver services Does not support rerouting



Supports rerouting lockout.


Does not support rerouting

Revertive Supported Supported Not supported

Pre-configuration of restoring route

Supported Supported Not supported

Service association Not supported Supported Supported

Service migration Supports migration between tunnel services and permanent connections.

Supports migration between silver tunnels and copper tunnels.

Supports migration between gold tunnels and silver tunnels.

Supports migration between gold tunnels and copper tunnels.


Tunnel level VC-4

D40V

D40V: 40-channel demultiplexing board with VOA

Version Description The available functional version of the D40V board is TN11.

Application As a type of optical demultiplexing unit, the D40V demultiplexes one channel of signals into a maximum of 40 channels of signals that comply with the related ITU-T Recommendations and adjusts the output optical power of each channel.

M40V

M40V: 40-channel multiplexing board with VOA

Version Description The available functional version of the M40V board is TN11.

Application As a type of optical multiplexing unit, the M40V board multiplexes a maximum of 40 channels of signals into one channel of signals that comply with ITU-T Recommendations, and adjusts the input optical power of each channel.

Functions and Features The M40V board is mainly used to multiplex signals, monitor performance of optical signals, monitor alarms and performance events, and adjust optical power.

Date post:	07-Nov-2014
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