Huawei MA5600 - Interruption of the BTV Service at an Interval of About 5 Minutes Due to Deferred Response to the General Query Packets

NGN Cases Chapter 2 MA5600T (IP DSLAM) Cases
Confidential Information of Huawei. No Spreading without Permission
26
Permission
Level:
04Common Users Permission
Phenomenon De
scription:
The topology is as following:
MA5600T--->CX300------>Cx600-->BRAS
Broadband version:V800R005B118
SIP version:V800R006C31B031
We have discovered many abnormal PADT packet attack generates a broadcast storm, the CPU usage is run
Alarm Informatio
n:
We can tell the status of GICD card from MA5600T is very busy blinking all the time.
Cause Analysi
s:
The packets are captured onsite and after analysing the packets. We discovered a large amount of abnormal
Handling Proces
s:
We filtered the packets on CX300 according to the souce MAC address of the abnormal broadcast storm PA
D
Suggestions and
Summary:
A patch to allow the DSLAM to identify and filter rogue PADT packets was developed and loaded on every sin
2.3 Interruption of the BTV Service at an Interval of About 5 Minutes Due to Deferred
Response to the General Query Packets
Title:
Interruption of the BTV Service at an Interval of About 5 Minutes Due to Deferred
Response to the General Query Packets
ID: SE0000356312
Information
Type :
Troubleshooting Cases Quality Level:
B
Update Time: 2008-11-10 17:11:53
Views: 14
Author: l42044
Product Family:
Broadband Access
Product:
MA5600T MSAN
Fault Type:
BTV Service
Keywords: IGMP, Interruption of the BTV service
Permission
Level:
04Common Users Permission
Phenomenon De
scription:
The subscriber can get online normally to watch BTV programs and the pictures are
normal. Four or five minutes later, however, the multicast video stream will be
interrupted. That is, either blank screen or service interruption occurs.
Alarm Informatio
n:
None
Cause Analysi
s:
After the program is online, the customer’s multicast server sends the IGMP V3 general
query packet in 60 seconds three times. If the multicast server does not receive any
response for these three times, the multicast server considers that the multicast
subscriber is offline, and then disconnects the transmitted multicast stream, causing
service interruption.
In this case, the multicast mode of the MA5600T is IGMP proxy. Because no general
query packet responding to the multicast service is received, it can be determined that
the fault occurs on the MA5600T. To prevent this fault temporarily, we can run a
specified command to periodically send the IGMP report packet to the multicast server.
Handling Proces
s:
1. When the multicast service is interrupted, run the display igmp user online all
command to check whether the multicast subscriber is online. It is found that the
subscriber gets offline already.
2. Capture packets on the upstream port. For the captured packets, see the attachment.
Through analysis, it is found that the customer’s multicast server sends the IGMP V3
general query packet after the program gets online, but the MA5600T does not respond.