During a lab test for the SmartAX MA5616 V800R307C02, a service interruption has occurred
due to an exception of the logic. The root cause, however, is not yet identified after more than three
months of efforts to reproduce the issue in the lab. This prewarning notice describes how to identify
this issue and restore the service.
Product Line: Access network Product Model: MA5616
Problem Description
Trigger conditions
Use a SmartAX MA5616 V800R307C02 that is in full configuration of service boards in the test.
Create a service port on each VDSL port, set up a point-to-point over Ethernet (PPPoE) connection
on each service port, and send the packets. Import the configuration file to the device and activate
the file multiple times, and then reset the system. Enable and disable the security function multiple
times and then perform dynamic host configuration protocol (DHCP) dialup and PPPoE dialup multiple
times.
Symptom 1. The dialup on all service ports fails. 2. The uplink and user ports collect statistics of the
received ports but the logic does not collect packet statistics.
Identification method
1 The system cannot forward services and all the services are interrupted. 2 Query the statistics of the
received and transmitted packets on the uplink and user ports to determine whether the packets are
transmitted to the FPGA logic. 2.1 The following screen shows the command and command output for
querying the statistics of the received and transmitted packets on the user port.
MA5616
2.2 The following screen shows the command and command output for querying the statistics of the
received and transmitted packets on the uplink port.
MA5616 display
3 If the received packets on the uplink and user ports increase, the packets are transmitted to the FPGA logic.
Then, query the statistics of the packets processed by the logic. 3.1 The following screen shows the command
and command output for querying the statistics of the packets processed by the logic.
MA5616 TYPR
4 If the values of all statistical items do not increase, an exception occurs on the logic. Note: All the preceding
four conditions must be met.
Root Cause The inner status mechanism of the logic becomes abnormal, resulting in the system failure to
transmit packets to the FPGA logic. As a result, the packets are discarded on the ingress port. The root cause
for the abnormality of the status mechanism has not yet been identified.
Impact and Risk
All the services on the system are interrupted.
Measures and Solutions Solution
There is little probability of this issue, which has not recurred during more than three months of issue
reproduction performed by Huawei′s R&D and test engineers, and during more than one year of live
network operation of this version. Currently, the most effective method of restoring the service is to
reset the system.
Workarounds
There is no workaround for this issue.
Attachment
No attachment is involved.
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