What’s the Reported about An IN_PWR_LOW Alarm ?

MC-A217 An IN_PWR_LOW Alarm Is Reported After an Optical-Layer ASON Service Is Configured on the ASON OptiX OSN 6800 NE

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

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
tt_wdm_mc_0217_fig01

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

  1. 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.
  2. Check fiber jumpers and find no exception. Thus, rule out the possibility that fiber jumpers are of bad quality.
  3. 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.
  4. 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.
  5. 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:

When configuring an ASON service or the OPA function, do not configure a mechanical VOA on the channels for adding or dropping wavelengths to prevent impacts on the OPA function.

What’s the MSTP Configuration of stp pathcost-standard?

Function Description

The multiple spanning tree protocol (MSTP) applies to the redundant network. MSTP is an improvement of STP and RSTP. MSTP prevents the proliferation and infinite cycling of the packets in the loop network. In addition, MSTP provides multiple redundant paths for VLAN data transmission to achieve the load-sharing purpose. The MA5680T/MA5683T/MA5608T supports MSTP, which is compatible with the STP and RSTP. It supports MSTP loop network that helps meet various networking requirements.

Function

The stp pathcost-standard command is used to set the calculation standard for the path cost. When the calculation standards for the path cost in the entire network is inconsistent and you need to set the calculation standard for the path cost of the device to be consistent with that of the entire network, run this command. After the calculation standard for the path cost is set, the path cost is calculated by the set standard automatically.

The undo stp pathcost-standard command is used to restore the default calculation standard for the path cost. After the default calculation standard for the path cost is restored, the path cost is calculated by the Huawei private calculation standard.

Format

stp pathcost-standard { dot1d | dot1t | legacy }

undo stp pathcost-standard

Parameters

Parameter Description
dot1d Indicates the IEEE 802.1D calculation standard. When you need to set the calculation standard for the path cost of the device as IEEE 802.1D, use this parameter.
dot1t Indicates the IEEE 802.1t calculation standard. When you need to set the calculation standard for the path cost of the device as IEEE 802.1t, use this parameter.
legacy Indicates the Huawei private calculation standard. When you need to set the calculation standard for the path cost of the device as Huawei private calculation standard, use this parameter.

Modes

Global config mode

Level

Operator level

Usage Guidelines

  • By default, the calculation standard for path cost is legacy.
  • After the calculation standard for the path cost is set, the device path cost is calculated by the standard automatically.
  • Different calculation standards define different path costs for ports. If the set calculation standard is different from the current standard, all ports use the default path cost of the set calculation standard. All path costs in the previous standard set by the user are lost because settings are invalid when the calculation standard for the path cost is changed.

Example

To set the calculation standard for path cost as IEEE 802.1d, do as follows:

huawei(config)#stp pathcost-standard                                            
{ dot1d<K>|dot1t<K>|legacy<K> }:dot1d                                           
                                                                                
  Command:                                                                      
          stp pathcost-standard dot1d

To restore the default calculation standard for path cost, do as follows:

huawei(config)#undo stp pathcost-standard

System Response

  • The system does not display any message after the command is executed successfully.

What’s the MSTP Configuration ofstp mode ?

stp mode

Function

The stp mode command is used to set the working mode of the Multiple Spanning Tree Protocol (MSTPMSTP). When the device connects to the device supporting the Spanning Tree Protocol (STP), run this command to realize the compatibility. After the working mode of MSTP is set, MSTP works in the set mode.

The undo stp mode command is used to restore the default working mode of MSTP. By default, the working mode of MSTP is MSTP mode.

Format

stp mode { stp | mstp }

undo stp mode

Parameters

Parameter Description
stp Sets the working mode of MSTP as STP compatible. When the device needs to run STP, use this parameter.
mstp Sets the working mode of MSTP as MSTP. When the device needs to run MSTP, use this parameter.

Modes

Global config mode, OSN 1500B, OSN 7500

Level

Operator level

Usage Guidelines

  • By default, the working mode of MSTP is MSTP mode.
  • This command may activate the domain configuration. The ERPS uses an MSTP instance and therefore the command execution may fail.
  • After the working mode of MSTP is modified, the system recalculates the building tree.
  • MSTP and RSTP are compatible and can identify the protocol packets mutually. STP cannot identify the MSTP packets. To realize that MSTP is compatible with STP, you can set two working modes: STP compatible mode and MSTP mode.
    • In STP compatible mode, bridges send STP BPDU packets.
    • In MSTP mode, bridges send MSTP BPDU packets. When it is found that the bridge is connected to the one that runs STP, the port becomes compatible with STP mode automatically.
  • When the network is stable, even if the bridge in the network segment which runs STP is disconnected, the related port still works in STP compatible mode. In this case, you can run the stp port mcheck command to force the port to work in MSTP mode.

Example

To set the working mode of MSTP as STP compatible, do as follows:

huawei(config)#stp mode                                                         
{ stp<K>|mstp<K> }:stp                                                          
                                                                                
  Command:                                                                      
          stp mode stp 
  Command is being executed. Please wait: 100%

To restore the default working mode of MSTP, do as follows:

huawei(config)#undo stp mode

System Response

  • The command execution duration depends on other configurations. If the duration is long, the system displays the progress.
  • The system does not display any message after the command is executed successfully.

Warning of an ARP Entry Dually-Transmitting Failure

Keywords: ATN 950B, ARP entry dually-transmitting failure, mixed VPN solution

Summary: A timing sequence error occurs when software performs batch backup on an ATN 950B NE functioning as a CSG running V200R002C00SPC300 or an earlier version. After a master/slave MPU switchover is performed several times, there is a possibility that the ARP entry dually-transmitting function fails. In this case, when network-to-user traffic transmitted along an MPLS LDP LSP(OSN 6800, OSN 8800) reaches the slave ASG in the mixed VPN solution, the ARP entry dually-transmitting failure causes a service interruption.

  • [ProblemDescription]

Usage scenario:

 

In a mixed VPN solution, LDP LSPs are established on the access ring network. ATN 950B NEs functioning as CSGs use the L2VPN function to transmit services and support the ARP entry dually-transmitting function configured using the mpls l2vpn arp-dual-sending command shown in the following table.

interface Ethernet0/3/0.1

mtu 2000

vlan-type dot1q 1

mpls l2vc 100.0.0.3 100 control-word raw//Configure the primary PW destined for ASG3.

mpls l2vc 100.0.0.4 101 control-word raw secondary//Configure the secondary PW destined for ASG4.

mpls l2vpn redundancy master//Configure PW redundancy protection to work in master/slave mode.

mpls l2vpn reroute delay 300//Set the delay for a PW switchback to 300s.

mpls l2vpn stream-dual-receiving//Configure the dually-receiving function for the primary and secondary PWs to prevent traffic loss during a traffic switchback.

mpls l2vpn arp-dual-sending //Configure ARP entry dually-transmitting function on both PWs to minimize traffic loss if a fault occurs on the primary PW.

Trigger conditions:

There is a high probability that the problem occurs if the following conditions are met. In the laboratory, the probability is approximate 70%.

  1. An MPU is reseated or the slave switchover command is run to perform a master/slave MPU switchover twice. Alternatively, the slave MPU is reseated or a command is run to reset the slave MPU.
  2. Another master/slave MPU switchoveris performed.

Note that there is no limit on the interval between master/slave MPU switchovers, and the ATN 950B NE must not be reset between master/slave MPU switchovers.

Symptom:

The slave ASG fails to learn the ARP entry mapped to the nodeB or eNodeB. As a result, network-to-user traffic on the slave ASG is interrupted.

Identification method:

  1. Checkthe tunnel token value of an L2VPN tunnel on the ATN 950B NE.

Run the display mpls l2vc interface interface-type interface-number command in the user view.

<HUAWEI>display mpls l2vc interface Ethernet0/3/0.1 

//In real-world situations, change Ethernet0/3/0.1 to the name of the actual interface that transmits L2VPN services.
*client interface       : Ethernet0/3/0.1 is up
Administrator PW       : no
session state          : up
AC status              : up
VC state               : up
Label state            : 0
Token state            : 0
VC ID                  : 1
VC type                : Ethernet
destination            : 172.1.1.178
local VC label         : 26           remote VC label      : 26
local AC OAM State     : up
local PSN OAM State    : up
link state             : up
local VC MTU           : 1500         remote VC MTU        : 1500
local VCCV             : cw alert ttl lsp-ping bfd
remote VCCV            : cw alert ttl lsp-ping bfd
local control word     : enable       remote control word  : enable
tunnel policy name     : —
PW template name       : —
primary or secondary   : primary
load balance type      : flow
Access-port            : false
Switchover Flag        : false
VC tunnel/token info   : 1 tunnels/tokens
NO.0  TNL type       : lsp   , TNL ID : 0x5  //0x5 is the token value used by the L2VPN tunnel. The token value is a hexadecimal number.
    Backup TNL type      : lsp   , TNL ID : 0x9

 

Check the MAC address carried in dually transmitted ARP packets.Run the display mplsada lsp token 5 command in the diagnostic view. Note that 5 is the token value obtained in Step 1.

Note that when the problem occurs, the destination MAC address carried in dually transmitted ARP packets is all 0s.

<HUAWEI>system-view

[HUAWEI]diagnose

[HUAWEI-diagnose]display  mplsada lsp token  5 //5 is the tunnel token value obtained in Step 1. This tunnel token value is a decimal number.

ulPdtHandle                     : 434410400
Protect Type          :3
Lsp or gre index      :5
Protect groupid       :1
ApsId                 :515
Primary pdthandle     :0x19e493a0
Backup pdthandle      :0x19df16d8

Nhi list begin
Nhi list end.  List count  :2

Main product info(TunnelId 5):
Ovid                  :0
MacIndex              :7
OutIfIndex            :337
TrunkorTp             :14
Trunk flag            :0
Nexthop               :0xc8010102
TunnelId              :5
Mac fake flag         :0
Exp Mode              :0
Exp value             :0
TnlType               :0
DestMac               :00:00:00:00:00:00 //The DestMac field indicates the destination MAC address for dually transmitted ARP packets. When the problem occurs, the destination MAC address is all 0s.

SrcMac                :f4:a1:a2:cf:33:01
Egress Intf index     :138
Mpls Tunnel index     :8
LspId or GreId        :4294967295
FqId                  :0
Dsid                  :0
Out stattisticId      :4294967295

 

 

  • [RootCause]
  1. When an ATN 950B is running properly, its master MPU is in slot 7, and the slave MPU is in slot 8. After a master/slave MPU switchover is performed by reseating an MPUor running commands, the MPU in slot 7 becomes the slave one, and the MPU in slot 8 becomes the master one. The MPU in slot 7 synchronizes data in a batch with the MPU in slot 8. Due to a timing sequence error, LDP data is backed up earlier than ARP data. As a result, the destination MAC address on the MPU in slot 7 is all 0s. Although the destination MAC address is incorrect, the MPU in slot 7 does not transmit services, and therefore, services are not affected.
  2. After the other master/slave MPU switchover is performed, the MPU in slot 7 becomes the master one. This MPUforwards dually transmitted ARP packets carrying the destination MAC address of all 0s. Upon receipt, the next-hop device considers the packets incorrect and discards them. As a result, the slave ASG fails to learn the ARP entry.
    • [ImpactandRisk]

When network-to-user traffic arrives at the slave ASG, traffic is interrupted.

  • [MeasuresandSolutions]

Recovery measures:

Note that the recovery measures will adversely affect services transmitted on the ingress, transit node, and egress along an existing tunnel within seconds.

Run the reset mpls ldp all command in the user view to reset MPLS LDP.

<HUAWEI> reset mpls ldp all

 

Workarounds:

None.

Solutions:

Perform either of the following steps to resolve the problem:

  • Install the patch V200R002SPH006 or later on the ATN 950B NEs running V200R002C00SPC300.
  • Upgrade a version earlier than V200R002C00SPC300 to V200R002C00SPC300 and then install the patch V200R002SPH006 or later.

Notice on Prewarning for Occasional MA5616 Database Clearing

Keywords

Frequent data saving, database exception, initialization

Summary

In MA5616 V800R312 equipped with an H831CCUB or H831CCUC control board, if data is frequently saved into the database, the database malfunctions after the MA5616 runs for a period of time. As a result, the MA5616 resets and starts from an empty database.

Problem Description

  • Trigger Conditions

This issue occurs if data is frequently saved into the database.

Each data saving reduces 256 bytes from the flash memory. When the remaining flash memory is about 1 KB larger than the database file size, this issue occurs sometimes.

  • Symptom

The MA5616 database is cleared.

  • Identification Method
  • For risky MA5616s:

Case 1:

This issue occurs after the MA5616 resets if the sizes of the database files in active and standby partitions are both 0 KB.

MA5616(su)%%filesystem cmd dir /all

Directory of flash:/

 

0    -rw-  15361414  May 13 2013 05:07:43   program.efs

………………………………

51   -rw-     59668  Aug 14 2013 04:04:16   log_oper00.dat

52   -rw-         0  Aug 11 2013 22:31:25   data.dat

53   -rw-         0  Aug 13 2013 02:27:19   data_bak.dat

57785 KB total (83 KB free)

 

Case 2:

This issue occurs after data is saved into the database several times and the MA5616 resets if the size of the database file in a partition is 0 KB.

MA5616(su)%%filesystem cmd dir /all

Directory of flash:/

 

0    -rw-  15361414  May 15 2013 00:20:39   program.efs

……………………………………

51   -rw-     58467  Aug 07 2013 14:57:17   log_oper00.dat

52   -rw-     95309  Aug 27 2013 22:35:31   data.dat

53   -rw-         0  Aug 27 2013 22:35:15   data_bak.dat

57785 KB total (94 KB free)

 

Case 3:

This issue occurs sometimes after the MA5616 runs a period of time and meanwhile data is frequently saved into the database if the sizes of the database files in active and standby partitions are greater than 0 KB but the remaining flash memory is nearly the same as the size of the database file.

MA5616(su)%%filesystem cmd dir /all

Directory of flash:/

 

0    -rw-  15361414  May 21 2013 21:51:07   program.efs

………………………………

49   -rw-     65296  Aug 22 2013 01:53:29   log_oper00.dat

50   -rw-     91636  Aug 27 2013 23:50:05   data.dat

51   -rw-     91636  Aug 27 2013 23:49:55   data_bak.dat

57785 KB total (107 KB free)

 

  • For affected MA5616s:

Log in to the MA5616s to query configuration files after confirming that the database is not manually cleared.

MA5616(config)%% display current-configuration

If only original configuration data remains in the configuration file, this issue has occurred.

Root Cause

The mechanism of writing data into the MA5616 database is defective. As a result, the dbupdate.bin redundant file uses the flash memory. If the remaining flash memory is about 1 KB larger than the database file size, saving data into the database results in a database exception. After the MA5616 resets, the database is cleared.

Impact and Risk

The MA5616 configuration restores to default settings, which results in service failures.

Measures and Solutions

  • Recovery Measures

For the affected MA5616s, perform the following operations:

  1. Configure data again or import the correct database file into the MA5616s. Then, reset the MA5616s.
  2. Run the savecommand to save the data.
  3. Run the following command to delete the binfile:

MA5616(su)%%filesystem cmd delete dbupdate.bin

The contents cannot be recycled!!! Delete flash:/dbupdate.bin?[confirm]:y

  • Workarounds

For the risky MA5616s, perform the following operations:

  1. Delete the binfile to ensure that the remaining flash memory is sufficient.

MA5616(su)%%filesystem cmd delete dbupdate.bin

The contents cannot be recycled!!! Delete flash:/dbupdate.bin?[confirm]:y

 

  1. In su mode, delete invalid database files (size: 0 KB), regardless whether the database file is in the active or standby partition.

MA5616(su)%%filesystem cmd delete data.dat

The contents cannot be recycled!!! Delete flash:/ data.dat?[confirm]:y

 

MA5616(su)%%filesystem cmd delete data_bak.dat

The contents cannot be recycled!!! Delete flash:/ data_bak.dat?[confirm]:y

 

  1. Manually save the database file. If the database file can be saved, the issue is rectified.
    • Preventive Measures

Load V800R312C00SPH206.

Prewarning Retraction Conditions

This prewarning can be retracted if issue triggering conditions are not met.

Attachment

None

Description on the flow control of the NG SDH EFT data board

Issue Description

Description on the flow control of the NG SDH (OSN 3500 OR OSN 7500)EFT data board.

Alarm Information

Null

Handling Process

(1) All the VCTRUNK support flow control

As for all the EFT boards (EFT4, EFT8 and EFT8A), all the vctrunk support flow control.

(2) The flow control mode is irrelevant to the working mode

No matter the working mode is auto-negotiation or forced mode, use ::ethn-cfg-set-fcmode: to set flow control mode.

(3) The flow control test has two directions: equipment to meter, and meter to equipment. 

The common test mode is from equipment to meter. The meter transmits traffic larger than the upper bandwidth of the vctrunk, the equipment transmits flow control frame to meter, and the meter reduces the traffic transmitted.

The test mode from meter to equipment indicates that the meter transmits flow control frame to the equipment to see the equipment transmits the flow control frame or discards it. The EFT board discards the flow control frame.

(4) Precautions on flow control test

If testing the flow control of negotiation, note the operation of the meter when using SMB to test. Set the MII register of the corresponding port of the meter, mark the tenth bit of the fourth register. And then click the auto-negotiation button again. This is a bug of the meter. Specific procedure is as follows:

(1) Right click, select “MII register”.
1
(2) Then, select “Reg4”, mark the “pause capable” of the tenth bit.

 

2

(3) At last, click “Restart Auto Negotiation”.

3

 

 

 

Root Cause

Null

Suggestions

Null

 

What’s the Failure of I-Type PDU Backplane on MA5600T due to Overcurrent

Keywords: MA5680T, Access network,

Summary: 

If an H801ESCA0 board (BOM number: 03030BYR) of a version earlier than VER.D is installed in the PDU and two channels of external power are input to the PDU, the PDU backplane may be burnt when the two copper plates are poorly connected due to misoperations.

[Problem Description]

  • Trigger conditions:
  1. An I-type PDU (BOM number: 02120328) is used on an MA5680T cabinet.
  2. Two channels of external power are input to the PDU.
  3. An H801ESCA0 board (BOM number: 03030BYR) of a version earlier than VER.D is installed in the PDU.
  4. The RTN copper plate on the PDU is poorly connected.

If conditions 1, 2, and 3 are met, this problem will be triggered when condition 4 occurs. The poorer the connection is, the higher the problem occurrence possibility is.

  • Symptom:

The PDU backplane is damaged due to overcurrent. The PCB is badly burnt, causing devices inside the cabinet to be powered off. The power is restored only after the PDU is replaced and services are interrupted for a long time.

  • Identification method:

Visually check the I-type PDU, especially the copper plates on the PDU. The following figure shows copper plates in good connection status.

1

The following figure shows copper plates in poor connection status.

2

[Root Cause]

The I-type PDU supports two external power inputs and four external power inputs. When four channels of power are input to the PDU, the copper plates must be removed. However, when two channels of power are input to the PDU, the copper plates are used to ensure a reliable connection to terminals and cannot be removed.

If the RTN copper plate is removed or poorly connected, the input current flows through the H801ESCA board to the negative terminal. In other words, the RTN terminals on the H801ESCA board are short-circuited. As a result, the circuit from the power backplane to the RTN copper plates on the H801ESCA0 board is overcurrent and burnt.

3

[Impact and Risk]

Devices inside the cabinet will be powered off. Services will be interrupted and can be restored only after the PDU is replaced.

[Measures and Solutions]

  • Recovery measures:

Replace the I-type PDU and restore power supply promptly.

  • Workarounds:
  1. During the installation and deployment of new devices, ensure that the RTN copper plate is properly connected when two channels of power are input to the PDU.

4

  1. Detail the device installation guide so that the copper plates can be properly connected. To obtain the detailed device installation guide, visit:

 

5

 

  • Preventive measures:

To prevent this problem, the new I-type PDU is optimized in the following aspects:

  1. Add a cap for the copper plate screw since March 30, 2013 so that it will not be mistakenly loosened.
  2. Upgrade the H801ESCA board to VER.D and replace the RTN copper plate with a diode insulator from September 30, 2013.

6

 

[Warning Expiration]

This warning automatically expires after related conditions are not met.

[Attachment]

None