Method of Configuring the Protection Subnet -part4

Creating a Linear MS Protection Subnet

In a chain network, an NE can protect a service in different sections of the fiber after a linear MS protection subnet is created.


You must be an NM user with NE and network maintainer authority or higher.

The NE data must be configured, and fibers must be properly created.


Fibers that are related to a linear MSP cannot be used by other protection subnets. That is, a linear MSP and other subnets cannot create virtual fibers together.


Starting the protocol controller may interrupt the service.


  1. Choose Service > SDH Protection Subnet > Create 1+1 Linear MSP from the Main Menu to display the Create Protection Subnet dialog box.


To create a M:N linear MS protection scheme, choose Service > SDH Protection Subnet > Create M:N Linear MSP from the Main Menu to display the related dialog box.

  1. Enter the name of the protection subnet. The default name is usually used, for example, 1+1_MSP_1.
  2. Select the rate of the protection subnet, for example, STM-4.
  1. Set Revertive Mode and Switching Mode based on the protection type and requirements.


For M:N linear MS protection scheme, set the number of working links to N. M indicates the number of protection links and cannot be set. Currently, the value is 1 only.

Revertive Mode refers to the handling strategy adopted after the faulty line recovers to normal.

Non-Revertive: The service does not automatically revert to the working channel after the faulty line recovers to normal.

Revertive: The service automatically reverts to the working channel after the faulty line recovers to normal.

Switching Mode refers to the switching strategy adopted after a fault occurs to the line.

Single-ended switching: To protect services, switching occurs at the receive end when the receive end is faulty and at the transmit end when the transmit end is faulty.

Dual-ended switching: To protect services, the switching occurs at the receive and transmit ends when either end is faulty.

If multiple protection subnets uses one port of a board, you need to check the Resource Sharing check box. If different protection subnets use different ports of a board, do not check this check box.

Select the Assigned by VC4 option when there are different VC4s belonging to different protection subnets to achieve MSP only in some channels protection. For example, for an STM-16 fiber, the VC4s 1-4 belong to an STM-4 MSP, and VC4s 5-8 belong to a PP.

  1. Add nodes to the protection subnet to be created. Double-click the NE on the Main Topology to add it to the node list in the left-hand pane. Meanwhile,  is displayed on the NE icon. If you want to cancel the selection, double-click the NE again.
  2. Click Next to proceed to the Select Link of the wizard. Set the Physical Link Information of Working Link and Protection Link.
  3. Click Finish to deliver the configuration data. The Operation Result prompt box is displayed. Click Close.
  4. Right-click the protection subnet and choose Protection Subnet Attributes from the shortcut menu.
  5. Click the Protection Subnet Maintenance tab to check whether the protocol controller starts.

If not, do as follows:

  1. Select all the NEs of the protection subnet.
  2. Right-click and choose Start/Stop Protocol > Start from the shortcut menu.
  3. Click Yes in the dialog box that is displayed twice. Ensure that the status of all the values in the Protocol Controller column is Protocol Started.

Click the Protection Subnet Parameters tab and set the WTR time and SD condition as needed. Click Apply to deliver the configuration.


The WTR time of all NEs in the sadme protection subnet should be the same.