Daily Archives: September 25, 2014

Be ware of Unnecessary ActiveStandby SCC Switching on OSN 3500&7500

Abstract
Because 3.3 voltage detecting circuits of SSN1GSCC02 and SSN3GSCC02 boards are of low precision, unnecessary active/standby SCC switching occurs, resulting in a possibility that NEs are unreachable to the NMS. If the ASON feature is enabled on NEs, data configuration may be lost during the active/standby SCC switching.

GSCC Board

[Problem Description]
If the following conditions are met, there is a possibility that the problem is triggered.

  • The NE runs active and standby SSN1GSCC02 boards that were manufactured before 2010-04-06 or active and standby SSN3GSCC02 boards that were manufactured before 2010-12-28.
  •  The FPGA of the SSN1GSCC02 boards or SSN3GSCC02 boards is of V120 or an earlier version.

Fault symptom:
Unnecessary active/standby SCC switching occurs on the NE that runs active and standby SCC boards; the standby SCC board is reset and reports the COMMUN_FAIL alarm after the active/standby SCC switching.

Identification method:
When the following four conditions are met, it can be determined that the problem is triggered:

  •  Active/Standby SCC switching occurs many times on the NE that runs active and standby SCC boards.
  •  The NE runs SSN1GSCC02 boards manufactured before 2010-04-06 or SSN3GSCC02 boards manufactured before 2010-12-28.

To query the type of the SCC board and when it was manufactured, run the :cfg-get-bdinfo: SCC board ID command in the Navigator (for Huawei OptiX OSN 3500 NEs, the SCC board IDs are 17 and 18; for OptiX OSN 7500 NEs, the SCC board IDs are 24 and 25). Then you can find information about the SCC board type and manufacturing date by checking the “BoardType” and “Manufactured” items in the returned information.
For example, query the type and manufacturing date of the SCC board on the Huawei transmission equipment OptiX OSN 3500 as follows:
:cfg-get-bdinfo:17
VERSION-INFO
/$[ArchivesInfo Version]
/$ArchivesInfoVersion=2.0
[Board Properties]
BoardType=SSN1GSCC02
BarCode=02664510A1000253
/$Item=03026645
/eDescription=System Control and Communication Board
/$PCBVersion=C
Manufactured=2010-01-06
ManufactureCode=1
/$CLEICode=

  • The FPGA of the GSCC board is of V120 or an earlier version.

To query the version of the FPGA, run the :ver command in the Navigator and you can find the FPGA version by checking “Logic” item in the returned information.
BIOS 08.09.03T02 20091113 10:57:13 inactive
ExtBios 09.09.04T01 20091118 11:48:14 active
NeSoft(D) 5.21.16.13 20091215 18:35:29
Platform(T) 5.00.07.C03T13 20090720 11:27:06
AosSoft(T) 5.99.02.10T26 20070228 10:49:11
Logic (U1004)120
Dsp

  •  To query records in the black box file bb1.log, run the :log-query: SCC board ID,”bb1.log” command in the Navigator.

For example, to query the black box file bb1.log of the SCC board in slot 17, run the following command:
:log-query:17,”bb1.log”
The returned information contains one of the following records:
…….
### Hard Register is not registered ###
…….
[HF:5][HF:8][HF:9]
…….

[Root Cause]
The 3.3 V voltage detecting circuits of the SSN1GSCC02 board manufactured before 2010-04-06 and SSN3GSCC02 board manufactured before 2010-12-28 are of low precision. Even if the 3.3 V power supply fluctuates within the allowed range, the board detects that there is an exception, triggering active/standby SCC switching. The SCC board is reset and reports the COMMUN_FAIL alarm.

[Impact and Risks]
For an NE that runs active and standby SCC boards, if unnecessary active/standby SCC switching occurs when the active SCC board is backing up data in batches, there is a possibility that data is lost; in addition, the NE is unreachable to the NMS transiently. For an NE that runs only one SCC board, there is no impact.

[Measures and Solutions]
Recovery measures:
【TN-R-201307】Rectification of Unnecessary ActiveStandby SCC Switching due
to Low Precision of 3.3 V Voltage Detecting Circuits on OSN 3500&7500 INTERNAL
If unnecessary active/standby SCC switching occurs when the NE is backing up data in batches, data is lost and services are interrupted. For a non-ASON NE, clear the NE databases, reset the SCC board, and download data from the NMS to the NE; for an ASON NE, contact R&D engineers for help.

Workarounds:
None
Solutions:
1. For NEs that can be upgraded:
First upgrade the FPGA. Upgrade the SSN1GSCC02 board manufactured before 2010-04-06 and SSN3GSCC02 board manufactured before 2010-12-28 to V100R008C02SPC500+SPH502 or a later V100R008C02 version, or V100R010C03SPC203+SPH207 or a later V100R010C03 version.
If the version of the SCC board is V100R008C02SPC200 and cannot be upgraded to V100R008C02SPC500+SPH502 or a later V100R008C02 version, or V100R010C03SPC203+SPH207 or a later V100R010C03 version, upgrade the FPGA of the SCC board to V130.

2. For NEs that cannot be upgrade:
Replace the SCC boards. Replace the SSN1GSCC02 board with an SSN1GSCC02 board manufactured after 2010-04-06 and the SSN3GSCC02 board with an SSN3GSCC02 manufactured after 2010-12-28.
For an ASON NE, replace the faulty SCC board with the N4GSCC board based on actual situations.
Solution of material handling after replacement:
Return the boards to Huawei headquarters.

[Rectification Scope and Time Requirements]
For the rectification scope, refer to the SSN1GSCC02 List and SSN3GSCC02 List.
It is required that the rectification is complete before 2014-04.

[Rectification Instructions]
Refer to the Replacement Guide for the GSCC Boards on the NG-SDH Equipment.

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