#osn6800

Hello everyone！

I will share with you the knowledge about Huawei OSN6800 inter-board communication.

There are two ways for the inter-board communication of the OSN6800, namely Ethernet and RS485. What information are they transmitted?

1. For a single subrack:

    1) RS485: Pass the information of various protection group protection switching, ASON intelligent software information, and the two types of information are transmitted by default 485 bus.

     2) Ethernet: All data except the data transmitted by RS485 are transmitted through Ethernet communication, including alarm reporting, configuration delivery, and so on.

2. For the master and slave subracks (multiple subracks):

        All the information between the master and slave subracks is transmitted by Ethernet, that is, the information exchange across the subracks.

to sum up:

1. RS485 has two paths, which can be used for backup. When both 485 buses fail, all RS485 information is transmitted by Ethernet.

An LDGF2 board on an OptiX OSN 1800 reports an OTU1_LOF alarm because the board at the opposite station transmits colorless light.

Product

OptiX OSN 1800,  OSN6800,  OSN8800

Fault Type

Optical Transponder Unit

Service Interruption

OTU1_LOF

Symptom

On a Metro WDM network, the OptiX OSN 1800 is deployed. Two stations are connected through the LDGF2 and LDGF boards, and the intermediate station is a regeneration station and uses the LWX2 board. The optical path between the LDGF board at upstream station A and the LWX2 board at regeneration station C is blocked. The other side of the LWX2 board transmits light forcibly and the LDGF2 board at downstream station B reports an OTU1_LOF alarm.

Cause Analysis

The LWX2 board at regeneration station C reports an R_LOS alarm and the LDGF2 board at downstream station B reports an OTU1_LOF alarm.

The corresponding board at upstream station A transmits colorless light.

The input optical power of station B is not within the permitted range.

The FEC type setting is incorrect.

The fiber transmission line is malfunctioning.

Procedure

Use an optical power meter to measure the output optical power from the LWX2 board to downstream station B. The optical power is within the permitted range. Therefore, cause 2 is ruled out.

On the NMS, query FEC Type and the setting is correct.

Check where the alarm is generated. The location information of the alarm is 1-LDGF2-201(LP1/LP1)-OUT1:1. This shows that the alarm is reported by the IN1 port on the LDGF2 board in slot 1 of station B. Therefore, the optical line between upstream station A and regeneration station C may be blocked and this causes an R_LOS alarm on the LWX2 board at station C. Because Automatic Laser Shutdown of the LWX2 board at the regeneration station is set to Disabled, and Laser Status is set to ON, the LWX2 board transmits colorless light to downstream station B. Therefore, an OTU1_LOF alarm is reported.

Repair the optical line between upstream station A and regeneration station C. Then the alarm is cleared.

Result

The problem is resolved.

Reference Information

When an OTU1_LOF alarm is reported on the NMS, check for the location information in the alarm to determine the port that reports the alarm. For the LDGF2 board, 201(LP1/LP1) indicates the IN1 and IN2 optical ports, and 202(LP2/LP2) indicates the IN3 and IN4 optical ports. The digit 1 at the end of the location information indicates the IN1 or IN3 optical port. The digit 2 indicates the IN2 or IN4 optical port. For example, 3-LDGF2-202(LP2/LP2)-OUT1:2 indicates the IN4 optical port on the LDGF2 board in slot 3. The location information of other boards can be deduced by analogy.

If the receive optical power is within the permitted range, determine whether the upstream station transmits colorless light. For the boards with the FEC function enabled, check that the FEC settings are correct.

Summary: 

The NE software V100R008C10SPC200 does not support hardware tributary subnetwork connection protection (SNCP) on the TN54THA and TN53TSXL boards. To be specific, a TN54THA or TN53TSXL board equipped with hardware tributary SNCP will insert an incorrect s-code to the cross-connect board on the NE. As a result, the cross-connect board will report a HARD_BAD alarm, affecting services on the NE.

Product Line: Transport network product line    Product Family: WDM products

Product Model: OptiX OSN 8800 V1R008C10SPC200, OSN 6800

[Problem Description]

Trigger conditions:

The NE software version is V100R008C10SPC200.

Hardware tributary SNCP has been configured on RX/TX ports 9–16 of a TN54THA board or the RX/TX port of a TN53TSXL board on the NE.

Hardware tributary SNCP is newly configured on RX/TX ports 9–16 of a TN54THA board or the RX/TX port of a TN53TSXL board on the NE.

The cross-connect board on the NE is TN16UXCM, TN52UXCH, TN52UXCM, TNK2USXH, or TNK2UXCT.

During NE expansion, the cross-connect boards on the NE are upgraded from TN16XCH, TN52XCH, TN52XCH02, TNK2SXH, TNK2XCT, TNK4SXM, TNK4SXM, or TNK4XCT to TN16UXCM, TN52UXCH, TN52UXCM, TNK2USXH, or TNK2UXCT.

When conditions 1, 2, and 5, or conditions 1, 3, and 4 are met, the NE will report a HARD_BAD alarm.

Symptom:

The NE reports a HARD_BAD alarm and services on the NE are affected.

Identification method:

Conditions 1, 2, and 5, or conditions 1, 3, and 4 are met, and the NE reports a HARD_BAD alarm. The alarm parameters are as follows: 0xf,0x5,0xa,0xff,0xff,0xff.

 [Root Cause]

The OptiX OSN 8800 V100R008C10SPC200 does not support hardware tributary SNCP on the TN54THA and TN53TSXL boards. If hardware tributary SNCP is configured on a TN54THA or TN53TSXL board, array violation will occur on the board, causing the board to insert an incorrect s-code to the cross-connect board on the NE. As a result, bit changes occur on the chip page of the cross-connect board. Consequently, the cross-connect board reports a HARD_BAD alarm.

 [Impact and Risk]

The network expansion is affected. When common cross-connect boards are upgraded to U-series cross-connect boards, the HARD_BAD alarm will be reported, and the tributary SNCP services on the TN54THA or TN53TSXL boards will be interrupted.

If U-series cross-connect boards are already used, the HARD_BAD alarm will be reported when tributary SNCP services are created. As a result, the new services cannot be provisioned but the existing services are not affected.

The existing tributary SNCP services are not affected in non-expansion scenarios.

[Measures and Solutions]

Recovery measures:

In expansion scenarios, use the NE software V100R008C10SPC300 instead of V100R008C10SPC200.

If tributary SNCP services fail to be created on the NE software V100R008C10SPC200, upgrade the NE software version to V100R008C10SPC300 or later.

Workarounds:

If tributary SNCP services are configured for the TN54THA or TN53TSXL board on an NE, use NE software V100R008C10SPC300 or later instead of V100R008C10SPC200.

Preventive measures:

The SC2 and the OAU boards are configured on different subracks. As a result, the SC2 board cannot be configured as an auxiliary detection board for the IPA protection group.

Product

OptiX BWS 1600G, OSN 6800, OSN 8800

Fault Type

Intelligent Power Adjustment (IPA)

Symptom

When configuring the IPA function, the user attempts to configure the SC2 board as an auxiliary detection board on the T2000 but fails.

Cause Analysis

The site that requires an auxiliary detection board is a back-to-back OTM site. The site has only one SC2 board. In addition, the SC2 board and the OAU board forming the IPA protection group are installed in different subracks.

This fails to follow the configuration principle for the IPA protection. That is, all functional boards related to the IPA function except the Raman amplifier board must be installed in the same subrack. The Raman amplifier board can be installed in another NE when inter-subrack communication is available.

Procedure

Install the existing SC2 board or add an SC2 board in the subrack where the IPA function need to be configured. If an SC2 board is added, it must be connected to the existing SC2 board.

Reference Information

The TN52TQX board in a subrack using the TN1K1AFB backplane reports the BUS_ERR alarm due to backplane limitations.

Product

OptiX OSN 6800,  Huawei Optix OSN8800

Fault Type

Tributary Unit and Line Unit

BUS_ERR

Symptom

A TN52TQX board is added to the subrack for expansion on network AJ that uses the OptiX OSN 6800. After four ODU2 services are configured on the TN52TQX and TN52NS3 boards, the TN52TQX board reports the BUS_ERR alarm.

Cause Analysis

Possible causes for this fault are as follows:

The slot into which the OTU board is inserted does not support 40G cross-connect capacity.

The cross-connect board does not support 40G cross-connect capacity in a single slot.

The backplane of the subrack does not support 40G cross-connect capacity in a single slot.

The cross-connect board, TN52TQX, or TN52NS3 board is malfunctioning.

Procedure

Query alarms. The BUS_ERR alarm is reported only for the third and fourth ODU2 services. This problem occurs on multiple boards. Therefore, the possibility that the board hardware is malfunctioning is ruled out.

Confirm that the TN52NQ2 board is housed in slot IU4, which supports 40G cross-connect capacity.

Confirm that the cross-connect board is the TN12XCS board, which supports 40G cross-connect capacity in a single slot.

Confirm that the backplane is TN1K1AFB, which does not support 40G cross-connect capacity in a single slot.

Restrictions on backplanes, cross-connect boards, and slots were not considered for single-slot 40G boards during the network expansion design. Therefore, the expansion fails.

Result

The problem is resolved.

Reference Information

For OptiX OSN 6800, three backplanes (TN1K1AFB, TN1K2AFB, and TN1K3AFB) and two cross-connect boards (TN11XCS and TN12XCS) are available. The restrictions on service capacity and cross-connection configurations of 40G boards vary according to backplanes and cross-connect boards. When planning a 40G network, notice the following restrictions:

Only eight pairs of cross-connect buses are available in a subrack using the TN1K1AFB backplane. The cross-connect capacity of the subrack is 20G (8 x ODU1). The subrack does not support single-slot 40G boards (such as the TQX and NQ2 boards) but supports two-slot 40G boards (such as the NS3 board).

Only eight pairs of cross-connect buses are available in a subrack using the TN11XCS boards. The cross-connect capacity of the subrack is 20G (8 x ODU1). The subrack does not support single-slot 40G boards but supports two-slot 40G boards.

A subrack using the TN12XCS boards and TN1K2AFB backplane can house single-slot 40G boards (such as the TQX and NQ2 boards) in four slots (slots 1, 4, 11, and 14). Each of the four slots has 16 pairs of cross-connect buses to support the cross-connect capacity of 40G (16 x ODU1). Each of the other slots in the subrack has eight pairs of cross-connect buses to support the cross-connect capacity of 20G (8 x ODU1). Single-slot 40G boards cannot be housed in these slots. All slots in the subrack support two-slot 40G boards.

Excessively high incident optical power results in poor performance of OTU boards.

Product

WDM

OptiX OSN 8800

OptiX OSN 6800

OptiX OSN 3800

Fault Type

Optical Power Abnormity

Optical Transponder Unit

Symptom

OptiX OSN 6800 V100R005C00SPC800 is used at the network AF. After the network is reconstructed to support ASON and the OPA preset insertion loss is adjusted, performance of services on all channels on a link deteriorates in a single direction. The pre-FEC BER changes from 1E-7/1E-8 to 1E-4/1E-5. In addition, there is a large number of post-FEC bit errors after the network adjustment.

Wavelength 54 is added at site A and dropped at site F, traversing sites B, C, D, and E. It has the poorest performance with the pre-FEC BER being 1E-4 and a large number of post-FEC bit errors. Wavelengths 56 and 26 with the same source and sink are added at site B and dropped at site E. They have different performance levels. There are pre-FEC bit errors, and sometimes post-FEC bit errors, and uncorrectable error blocks in wavelength 56. Wavelength 26 does not have pre-FEC bit errors.

Figure 1 shows the network topology of the network AF.

Figure 1

The Network Topology of AF Network

Sites C and D are two fiber connection sites that connect G.653 and G.652 fibers. No equipment is installed at the two sites. G.653 fibers connect sites C and D.

The lines between sites A and B and between sites E and F are configured with 1+1 protection.

Cause Analysis

Possible causes for this fault are as follows:

The input optical power of the OTU board is close to the upper or lower threshold.

Two interconnected OTU boards have different FEC settings.

Boards (OTU or optical-layer boards) are malfunctioning.

The optical cable or the pigtail is faulty.

The system OSNR is too low, which may be caused by inappropriate optical power commissioning, incorrect dispersion compensation, or non-linear effects.

Procedure

Query the receive optical power and FEC configuration of the OTU board. No exception is found. Perform a selfloop using the pigtail. The OTU board is functioning properly. The system performance deteriorates only after the OPA function starts. Therefore, you can infer that the deterioration is related to the OPA function. In addition, starting the OPA function affects the line optical power.

Query the optical power at each site. The output optical power of site B is 21.8 dBm (the incident optical power of a single wavelength is 9.5 dBm). The line attenuation is 9.125 dB. The incident optical power of the G.653 fiber at site C is about 0.4 dBm. This single-wavelength incident optical power is much higher than the recommended value in the system design. The single-wavelength incident optical power that is recommended for an 80-channel system using G.653 fibers is –7 dBm. Excessively high incident optical power causes the non-linear effect FWM. As a result, the system performance deteriorates sharply.

Modify the reference input and output optical power of the OAP function so that the single-wavelength incident optical power for G.652 fibers is +1 dBm, and that for G.653 fibers is –7 dBm. By doing this, the non-linear effect FWM of the G.653 fibers is minimized, and the system performance is improved. The pre-FEC BERs for all wavelengths are lower than 1E-10. The output optical power of wavelength 56 at site B is 11.4 dBm, and that of wavelength 26 at site B is 12.4 dBm. However, the two wavelengths have different performance levels. This difference is because wavelength 56 in the 80-channel system is 1550 nm, which is the zero dispersion point of G.653 fibers. The non-linear effect FWM increases when the incident optical power is high or the wavelength is close to the zero dispersion point.

Result

The problem is resolved.

Reference Information

In a system using various fibers, the transmission performance of optical signals varies with the fiber parameters.

The EPL service is interrupted due to mismatched service modes of the L4G boards, the sites report the R_LOF, ODU5G_PM_AIS, OTU5G_LOF and LINK_ERR alarms.

Product

OptiX OSN 6800

OptiX OSN 8800

Fault Type

Service Interruption

R_LOF

ODU5G_PM_AIS

OTU5G_LOF

LINK_ERR

Symptom

On a network, an EPL service is configured between sites A and B. Site A reports an R_LOF alarm. Site B reports the ODU5G_PM_AIS, OTU5G_LOF and LINK_ERR alarms. The fibers inside sites A and B are connected correctly. The optical power of different sections on the line between site A and site B is normal but the EPL service between the two sites is unavailable.

Cause Analysis

The possible causes of the fault are as follows:

The configuration parameters of the two sites may be set incorrectly.

Procedure

Check the configuration parameters of the EPL service at the two sites, and find that the configuration parameter settings are consistent. The check steps are as follows:

Check the optical power between sites A and B and find that the optical power is normal. The check steps are as follows:

Check the parameter settings of the optical interfaces on the L4G board. It is found that the service mode of the L4G board at site A is set to SDH, whereas the service mode of the L4G board at site B is set to OTN. The steps for setting the service mode are as follows: The problem is resolved after the service modes of the two L4G boards are set to the same value.

Select the L4G board in the NE Explorer, and then choose Configuration > Ethernet Interface Management > Ethernet Interface from the Function Tree. Select External Port.

Click the Basic Attributes tab. Then, click Query to view the attributes of each optical interface on the L4G board.

Click the Flow Control tab to view the flow control modes.

Click the Tag Attributes tab to view the tag setting of each optical interface on the L4G board.

Click the Network Attributes tab to view the attributes of each optical interface on the L4G board.

Select the L4G board in the NE Explorer, and then choose Configuration > Ethernet Interface Management > Ethernet Interface from the Function Tree. Select Internal Port.

Click the Tag Attributes tab to view the tag setting of each optical interface on the L4G board.

Click the Network Attributes tab to view the attributes of each optical interface on the L4G board.

Select the NE in the NE Explorer and choose Configuration > WDM Service Management from the Function Tree. On the WDM Cross-Connection Configuration tab page, check the parameter settings and change them if necessary.

Select the L4G board in the NE Explorer, and then choose Configuration > Ethernet Service > E-Line Service from the Function Tree. Check the EPL service parameters, including direction, source port, sink port, and change the parameter settings if necessary.

In the NE Explorer, select the board whose optical power you need to query. Choose Configuration > Optical Power Management from Function Tree.

Click Query to read the current optical power value from the NE. The Operation Result dialog box is displayed, indicating that the operation is successful.

Click Close.

Select the L4G board in the NE Explorer, and then choose Configuration > WDM Interface from the Function Tree. Select By Board/Port (Channel).

Select Channel or Board from the drop-down list.

Sequentially check the parameter settings of each optical interface on the L4G board or attribute settings of the board on the Basic Attributes, Overhead Byte, and Advanced Attributes tab pages and ensure that the parameter settings of the two L4G boards are the same.

Result

The problem is resolved.

Reference Information

Conclusions and suggestions for this case are as follows:

An IN_PWR_LOW alarm is reported after an optical-layer ASON service is configured on the ASON OptiX OSN 6800 NE.

Product

OptiX OSN 6800,  Huawei Optix OSN8800 T16

Fault Type

ASON

IN_PWR_LOW

Symptom

During expansion of an ASON OptiX OSN 6800 NE at an office, the opposite NE reports an IN_PWR_LOW alarm after an ASON service is configured on the ASON NE.

Figure 1 shows how the fibers inside the NE are connected.

Figure 1

The Fibers Connection Inside One NE

Cause Analysis

When an ASON service is configured, a fiber connection and an optical cross-connection are created from the OTU board to the FIU board. After the optical cross-connection is created, the OPA function automatically sets the attenuation of the VA4 board to achieve automatic power adjustment of the WDM system.

After a field inspection, it is found that the OPA function sets the attenuation of the VA4 board to a great value, thus resulting in excessively low output optical power.

Procedure

Verify that the insertion loss of the boards (602-NS2 and 509-OBU1 in the preceding figure) between the OTU and OA boards and the insertion loss of 506-M40 are lower than 6.5 dB. This meets the attenuation requirement as the attenuation margin for the boards between the OTU and OA boards is 20 dB.

Check fiber jumpers and find no exception. Thus, rule out the possibility that fiber jumpers are of bad quality.

Check the output optical power threshold of the OTU board and the rated optical power of the OA board and find the settings are correct.

Find that a mechanical VOA is installed between the OTU and VA4 boards and the attenuation of the VOA is relatively high. This is why the optical power from the OTU board to the OA board is low and the opposite NE reports an IN_PWR_LOW.

Further analyze the wavelengths sent to the same M40 board and find that some channels are configured with mechanical VOAs but some are not. In addition, the attenuation values of the mechanical VOAs are different. In this case, the optical power of all the wavelengths cannot be flattened even though OPA adjustment is successful.

Result

The problem is resolved.

Reference Information

Conclusions and suggestions for this case are as follows: