The A_LOC on Huawei Optix OSN2500 is an alarm indicating the loss of clock in the upstream direction of the bus.
Parameters
When you view an alarm on the network management system, select the alarm. In the Alarm
Details field display the related parameters of the alarm. The alarm parameters are in the
following format: Alarm Parameters (hex): parameter1 parameter2...parameterN. For details
about each parameter, refer to the following table.
Impact on the System
When the A_LOC alarm occurs, the services carried by the board path are interrupted.
Possible Causes
The possible causes of the A_LOC alarm are as follows:
The PDH equipment interconnected to the service path is faulty.
The service type is incorrectly configured.
The service cross-connection is incorrectly configured.
The board hardware is faulty.
The cross-connect and timing board is faulty.
Procedure
Step 1 Check whether Huawei PDH equipment interconnected to the service path is faulty. If yes, take priority to remove the fault, and then check whether the A_LOC alarm is cleared.
Step 2 View the A_LOC alarm on the U2000, and then confirm the path number according to the alarm parameters.
Step 3 Check whether the service configuration of the path is correct. Make sure that the service type
at the local end is consistent with that at the remote end, and the cross-connection is correctly
configured. Then check whether the A_LOC alarm is cleared.
Step 4 If the alarm persists, check whether any hardware of the board that reports the A_LOC alarm is faulty on the U2000. If yes, perform a cold reset on the board. Then check whether the A_LOC
alarm is cleared.
Step 5 If the alarm persists, replace the board.
Step 6 If the alarm persists, perform a cold reset on the cross-connect and timing board. Then check
whether the A_LOC alarm is cleared.
Step 7 If the alarm persists, check whether the cross-connect and timing board is faulty. If yes, replace the cross-connect and timing board. Then the A_LOC alarm is automatically cleared.
Showing posts with label Huawei OSN 2500. Show all posts
Showing posts with label Huawei OSN 2500. Show all posts
Tuesday, June 6, 2017
Thursday, March 23, 2017
How to Troubleshoot the Pointer Justification on Huawei OptiX OSN 2500?
A pointer justification event means that some NEs are not completely synchronized in Huawei SDH
network equipment. If only a pointer justification event occurs, the services are not affected. To enhance
the transmission network stability, however, you need to find out the causes and eliminate the
pointer justification event.
Mechanism of Pointer Justification
Pointer justifications occur when the clocks between the NEs are not fully synchronized.
In an SDH network, there are two kinds of pointers: administrative unit pointer (AU-PTR) and
tributary unit pointer (TU-PTR). There are two corresponding pointer justifications, AU pointer
justification and TU pointer justification. The generation mechanism of these two kinds of
pointer justification is mostly the same. For details, see Chapter 1 "Generation of Alarm and
Performance" of Huawei OptiX OSN 2500 Intelligent Optical Transmission System Alarms and
Performance Events Reference.
Generation Mechanism of AU Pointer Justification
the E1 service between NE1 and NE6 passes through the intermediate NEs at
the VC-4 level. NE1 is the clock source, and the other NEs trace the clock signal of NE1
westwards. If the clocks of NEs 2 and 3 are not synchronous, the east optical board of NE2 and
the west optical board of NE3 generate the AU pointer justifications. These justifications may
cause the west optical boards of NEs 1, 4, 5 and 6 to generate pointer justifications.
If the clock of NE2 runs faster than that of NE3, the east optical board of NE2 executes the
AU positive pointer justification. At the same time, the west optical board of NE3 executes
the AU negative pointer justification.
If the clock of NE2 runs slower than that of NE3, the east optical board of NE2 executes
the AU negative pointer justification. At the same time, the west optical board of NE3
executes the AU positive pointer justification.
Detection Report of Pointer Justification
The location where AU pointers are generated and reported is different from that of TU pointers.
When a local station generates an AU pointer justification, it neither detect nor report the AU
pointer justification. Instead, this station transmits the pointer justification information to the
remote station through the H1 and H2 bytes. The remote station will report the event of the AU
pointer justification by interpreting the H1 and H2 bytes. Therefore, in remote detection mode,
if the remote station reports the AU pointer justification event, it means that the pointer
justification is generated in the local station.
Fault Locating Flow
The clock out-of-synchronization is the primary cause of pointer justification. Locate faults
mainly by handling problems related to the clocks. The fault should be located based on the
service direction, clock tracing direction, detection report location of pointer justification and
the generation location of pointer justification.
network equipment. If only a pointer justification event occurs, the services are not affected. To enhance
the transmission network stability, however, you need to find out the causes and eliminate the
pointer justification event.
Mechanism of Pointer Justification
Pointer justifications occur when the clocks between the NEs are not fully synchronized.
In an SDH network, there are two kinds of pointers: administrative unit pointer (AU-PTR) and
tributary unit pointer (TU-PTR). There are two corresponding pointer justifications, AU pointer
justification and TU pointer justification. The generation mechanism of these two kinds of
pointer justification is mostly the same. For details, see Chapter 1 "Generation of Alarm and
Performance" of Huawei OptiX OSN 2500 Intelligent Optical Transmission System Alarms and
Performance Events Reference.
Generation Mechanism of AU Pointer Justification
the E1 service between NE1 and NE6 passes through the intermediate NEs at
the VC-4 level. NE1 is the clock source, and the other NEs trace the clock signal of NE1
westwards. If the clocks of NEs 2 and 3 are not synchronous, the east optical board of NE2 and
the west optical board of NE3 generate the AU pointer justifications. These justifications may
cause the west optical boards of NEs 1, 4, 5 and 6 to generate pointer justifications.
If the clock of NE2 runs faster than that of NE3, the east optical board of NE2 executes the
AU positive pointer justification. At the same time, the west optical board of NE3 executes
the AU negative pointer justification.
If the clock of NE2 runs slower than that of NE3, the east optical board of NE2 executes
the AU negative pointer justification. At the same time, the west optical board of NE3
executes the AU positive pointer justification.
The location where AU pointers are generated and reported is different from that of TU pointers.
When a local station generates an AU pointer justification, it neither detect nor report the AU
pointer justification. Instead, this station transmits the pointer justification information to the
remote station through the H1 and H2 bytes. The remote station will report the event of the AU
pointer justification by interpreting the H1 and H2 bytes. Therefore, in remote detection mode,
if the remote station reports the AU pointer justification event, it means that the pointer
justification is generated in the local station.
Fault Locating Flow
The clock out-of-synchronization is the primary cause of pointer justification. Locate faults
mainly by handling problems related to the clocks. The fault should be located based on the
service direction, clock tracing direction, detection report location of pointer justification and
the generation location of pointer justification.
a: The first station refers to the station that first reports the pointer justification in the service direction, which is the same as the clock direction, that is, in the clock tracing direction.
b: The first station has no AU pointer justification, that is, it only has the TU pointer justification. You should handle the problem of TU pointer justification.
Thursday, March 31, 2016
Huawei OptiX OSN 2500 Review
Network Application
The OptiX OSN 2500 intelligent optical transmission system (hereinafter referred to as the Huawei OSN 2500) developed by Huawei is the next-generation intelligent optical transmission equipment.
The OptiX OSN 2500 integrates the following technologies to transmit voice and data services on the same platform with high efficiency:
- Synchronous digital hierarchy (SDH)
- Plesiochronous digital hierarchy (PDH)
- Ethernet
- RPR(Resilient Packet Ring)
- Asynchronous transfer mode (ATM)
- Storage area network (SAN)
- Wavelength division multiplexing (WDM)
- Digital data network (DDN)
- Automatically switched optical network (ASON)
- Microwave Technology
Appearance of the OptiX OSN 2500
The OptiX OSN 2500 is used at the access layer and the convergence layer of a metropolitan area network (MAN). The OptiX OSN 2500 can also be networked with the following equipment to optimize the investment for customers:
- OptiX OSN 9500
- OptiX OSN 7500
- OptiX OSN 3500
- OptiX OSN 3500 II
- OptiX OSN 2500 REG
- OptiX OSN 1500
- OptiX 2500+(Metro 3000)
- OptiX 155/622H(Metro 1000)
Network application of the OptiX OSN 2500
Networking Topology
The OptiX OSN 2500 supports topologies such as chain, ring, tangent rings, intersecting rings, ring with chain, dual node interconnection (DNI), hub, and mesh at the STM-1/STM-4/STM-16/ level.
The OptiX OSN 2500 supports the separate and hybrid configuration of the following types of NEs:
- Terminal multiplexer (TM)
- Add/drop multiplexer (ADM)
- Multiple add/drop multiplexer (MADM)
- The OptiX OSN 2500 can be interconnected with Huawei OSN, DWDM, and Metro equipment series, to provide a complete transmission network solution.
NOTE:
When the equipment is being interconnected, make sure that the K bytes to be received and transmitted are on the same path at both ends.
- The OptiX OSN 2500 can be used with another OptiX OSN equipment to provide a complete ASON solution. This solution covers all the layers including the backbone layer, the convergence layer, and the access layer.
- Through an SDH interface or a GE interface, the OptiX OSN 2500 can be interconnected with the WDM equipment.
- Through an SDH, PDH, Ethernet, ATM, or DDN interface, the OptiX OSN 2500 can be interconnected with the OptiX Metro equipment.
Basic networking modes of the OptiX OSN equipment series
| Networking Mode | Topology | |
| 1 | Chain |  |
| 2 | Ring |  |
| 3 | Tangent rings |  |
| 4 | Intersecting rings |  |
| 5 | Ring with chain |  |
| 6 | DNI |  |
| 7 | Hub |  |
| 8 | Mesh |  |
Legends: | ||
Telephone: 852-30623083
Email: Sales@Thunder-Link.com
Website: http://www.thunder-link.com
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