Huawei N2SLQ16 Board Interconnected with the TQS Board Reports an R_LOS Alarm

Symptom

When Huawei N2SLQ16 board on an Huawei OptiX OSN 7500 NE is interconnected with the TQS board on an OptiX OSN 6800 NE at an office and no service is deployed on the TQS board, the N2SLQ16 board reports an R_LOS alarm when the optical power is normal. After a software outloop is performed on the TQS board, the alarm reported on the N2SLQ16 board is changed to R_LOF.

Cause Analyze

No service is deployed on the TQS board. Therefore, an R_LOF not an R_LOS alarm should be reported when the TQS board is interconnected with the N2SLQ16 board and when the optical power is normal. Since the N2SLQ16 is not faulty, the possible cause of the R_LOS alarm is that signals are lost rather than that the optical power is abnormal. That is, the N2SLQ16 board may receive white lights.

Under the condition that signals are scrambled but not framed on the TQS board, the initial values of the output signals on the WDM side of the TQS board are all zero. At this time, the optical module on the TQS board outputs white lights. When a loopback is performed on the TQS board, that is, signals on the optical module are framed and scrambled for initialization, the TQS no longer outputs white lights but random signal lights. As a result, the downstream N2SLQ16 board does not report the R_LOS alarm.

Procedure

1.         Query the alarm mode of the OptiX OSN 6800 NE on the T2000. The result shows that the alarm mode is set to automatic reversion for the NE but the automatic reversion function is not enabled at the optical interface.

2.         Replace the N2SLQ16 board or the optical module on the board but the problem persists. Perform a hardware loopback at the optical interfaces on the N2SLQ16 board by using an optical fiber. The R_LOS alarm disappears. The possibility that the N2SLQ16 board or the optical module on the board is faulty is excluded.

3.         Analyze that the TQS board interconnected with the N2SLQ16 board may be faulty. That is, the lights transmitted by the TQS board may be white, and therefore signals on the N2SLQ16 board are lost. On the T2000, set the client-side optical interfaces on the TQS board to Outloop. At this time, the alarm on the N2SLQ16 board is changed from R_LOS to R_LOF. The fault is rectified.

Huawei OTN Equipment Fails to Transparently Transmit Ethernet Clock Signals

Symptom Clocks between PTN equipment must be synchronized. Network AM using the OTN network architecture is configured between PTN equipment to transparently transmit clock signals from upstream PTN equipment to downstream PTN equipment or to implement network-wide clock synchronization. After the network is set up according to the network topology, the clock synchronization fails. The following figure shows the network topology. Figure 1 The Network Topology of AM Network  Cause Analysis The OptiX OSN 6800/OptiX OSN 8800 earlier than V100R006C01 cannot directly restore clock signals from 10GE services transmitted from PTN equipment. Therefore, clock signals are transparently transmitted from the upstream PTN equipment to the downstream PTN equipment. According to the network topology, PTN equipment transmits 10GE LAN services to the OTN network that consists of NG WDM equipment. The TN52TQX board is configured on the OptiX OSN 6800/OptiX OSN 8800 equipment and is set to the MAC Transparent Mapping (10.7G) mode. This network topology, however, cannot implement clock transparent transmission because of the MAC Transparent Mapping (10.7G) mode and Bit Transparent Mapping (11.1G) mode when clock signals are processed. 10GE LAN services can be set to 10GE LAN MAC Transparent Mapping (10.7G) mode or 10GE LAN Bit Transparent Mapping (11.1G) mode. The differences are as follows: ·         In the 10GE LAN MAC Transparent Mapping (10.7G) mode: 10GE LAN signals are encapsulated in the GFP-F mode and then mapped into standard OTU2 frames. In this mode, 10GE MAC frames are transparently transmitted. In addition, the equipment working in this mode supports standard OTU2 frames at the rate of 10.71 Gbit/s and can be interconnected with all equipment that supports standard protocol rates. In this mode, the local clock is traced and service clock signals cannot be transparently transmitted. ·         In the 10GE LAN Bit Transparent Mapping (11.1G) mode: Client 10GE LAN signals are directly mapped into OTU2 frames and transmitted at the rate of 11.1 Gbit/s. The transmission is implemented by extending the OTU2 frame structure and the transmission rate is higher than standard OTU2 signals. In this mode, the service clock is traced, and service clock signals can be transparently transmitted after the line rate is set to speed-up mode for the TN52TQX board. ·         To transmit link information in client services, you must set the MAC Transparent Mapping (10.7G) mode and enable the LPT function or set the Bit Transparent Mapping (11.1G)mode for the TN52TQX board. Procedure 1.    Set the Working Mode to Bit Transparent Mapping (11.1G) mode and the line rate to Speed-up Mode for the service board. Result The problem is resolved. Reference Information The NG WDM equipment traces the local clock or service clock based on the service type. Generally, the service clock is traced, and clock transparent transmission is supported when OTN boards are configured with the maximum supported cross-connect granularity and are set to the Speed-up Mode. Clock synchronization can be achieved by means of transparent transmission and network-wide clock synchronization. The OptiX OSN 6800/OptiX OSN 8800 earlier than V100R006C01 can only transparently transmit 10GE services and clocks between PTN equipment. The same is true for SDH services (transparent transmission is implemented using SDH boards). Network-wide clock synchronization can be achieved only when the TN52TOG board is interconnected to PTN equipment to transmit GE services. On the OTN network, the boards that support the IEEE 1588 feature can transmit physical clocks.

What should we pay attention to when use Huawei 40G OTN line board

The TN54NS3/TN55NS3 board for the OptiX OSN 6800/OptiX OSN 8800 universal platform subrack only supports relay mode. TN56NS3 board for the OptiX OSN 8800 universal platform subrack only supports relay mode.

When the TN56NS3 board is used to receive SDH services, the SDH service license for universal line boards is required.

When the TN56NS3 board is installed in a general OptiX OSN 8800 T64 subrack, the XCT+SXH or XCT+SXM cross-connect boards must be used. When the TN56NS3 board is installed in an enhanced OptiX OSN 8800 T64 subrack, the XCT+SXH, XCT+SXM, or UXCT+USXH cross-connect boards must be used. When the TN56NS3 board is installed in an OptiX OSN 8800 T16 subrack to receive SDH services, the TN16UXCM cross-connect board must be used.

When SDH services are provisioned, the TN56NS3 board can be used only in an independent subrack, but not in a master or slave subrack. When OTN services are provisioned, the TN56NS3 board can be used in an independent subrack, a master subrack, or a slave subrack.