Verifying Client 1+1 Protection Switching

This section takes a network formed by two OTM stations as an example to describe the test procedure of the client 1+1 protection switching that is realized by using the OLP.

Prerequisites

The client 1+1 protection must be configured.

The fiber connections between station A and station B must be complete.

The equipment must be running normally.

Tools, Equipment and Materials

U2000 Web LCT, signal analyzer, optical fiber, flange, optical attenuator

Set-up Diagram

The diagram of testing client 1+1 protection switching is shown in Figure 1.

Figure 1 Testing the client 1+1 protection

: Fixed optical attenuator

Procedure

Connecting Test instruments
1. In station A, respectively connect the output and input optical interfaces of the signal analyzer to the TI and RO interfaces on the client side of the OLP board through two fixed optical attenuators.
2. In station B, connect the RO interface to the TI interface on the client side of the OLP board through a fixed optical attenuator, to realize the loopback on the client side, as shown in Figure 1.
3. Test the channel by using a signal analyzer to ensure that no bit error is generated.
Querying the Normal Channel Status of the Station A
1. Log in to the U2000 Web LCT. Double-click the ONE icon of the Station A in the Main Topology, and the status figure of the ONE is displayed.
2. Right-click the NE icon where the OLP board is located and select NE Explorer to display the NE Explorer dialog box.
3. Select the NE from the Navigator Tree and choose Configuration > Port Protection from the Function Tree.
4. Click Query, a prompt appears to indicate that the operation was successful. Click Close. And all protection groups are listed in the protection group list in the right-hand pane.
5. Check the channel status of the client 1+1 protection. The Working Channel Status and the Protection Channel Status is Idle.
Testing the Protection Switching of the Equipment
1. The switching test of the client 1+1 protection can be performed in two ways.
  - Method 1: fiber removing. Remove the fiber of the IN optical interface of the working OTU1 board in station A to perform the switching, as shown in Figure 1.
  - Method 2: forced switching. On the U2000 Web LCT, log on into the protection group of station A. Right-click the desired protection group, and select Force to Protection Channel to perform the switching. Click OK in the dialog box displayed.
  NOTICE:
  In Method 1, you must disconnect the fiber that inputs signals to the OTU1 board in station A. Otherwise, protection switching may be performed twice or no protection switching is performed. In this way, the detected switching time is more scientific.
2. Query the channel states of the client 1+1 protection in station A.
  - Choose Configuration > Port Protection from the Function Tree. Click Query, a prompt appears to indicate that the operation was successful. Click Close.
  - In the fiber removing mode, Working Channel is 1(RI1/TO1), and Protection Channel is 2(RI2/TO2). Working Channel Status is SF Switched; Protection Channel Status is Idle. Switching Status is Switching.
  - In the forced switching mode, Working Channel is 1(RI1/TO1), and Protection Channel is 2(RI2/TO2). Working Channel Status and the Protection Channel Status is Idle. Switching Status is Switching.
3. In the NE panel of the Station A, right-click the OLP board and select Browse Current Alarms.
  - If the protection group is automatically switched, the OLP board reports AUTOSW.
  - If the protection group is forced switched, the OLP board reports FRCDSW.
4. Test the services and switching time by using a signal analyzer. The services should be available, no bit error is generated, and the switching time should be less than 50 ms.
5. To restore the test environment of the two switching modes in Step 1, the following two modes can be respectively used:
  - Fiber removing mode: Reconnect the fiber.
  - Forced switching mode: Right-click the desired protection group in the Protection Group, and select Clear. Click OK in the dialog box displayed.
  NOTE:
  If the Restore Mode field is set to Non-Revertive, right-click the desired protection group and then choose Manual to Working Channel from the shortcut menu. After that, right-click the same protection group again and then choose Clear from the shortcut menu. Click OK in the dialog box displayed.
6. After the time set in WTR Time(mm:ss) field, Click Query, a prompt appears to indicate that the operation was successful. Click Close. And Switching Status of the protection group should be Idle.