Huawei eSpace IAD - 2 Analyzing and Rectifying Faults; 2.1 Call Faults

eSpace IAD
Troubleshooting
2 Analyzing and Rectifying Faults
Issue 02 (2012-02-29)
Huawei Proprietary and Confidential
Copyright © Huawei Technologies Co., Ltd.
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2 Analyzing and Rectifying Faults
About This Chapter
2.1 Call Faults
2.2 Fax and Modem Faults
2.3 Other Faults
2.1 Call Faults
2.1.1 IAD Phone One-Way Audio Caused by the Defense Against
UDP Flood Attacks
Symptom
When a user under the IAD makes a call to an onsite mobile phone user, the mobile phone
user cannot hear the calling party's voice for several seconds. This fault occurs when the
traffic is high.
Network:
IAD user-IAD-SBC-UMG
Cause
The defense against UDP Flood attacks is enabled for the SBC.
Solution
Step 1 Capture packets on the IAD, between the IAD and the SBC, and between the SBC and the
UMG.
Step 2 Analyze the captured packets.
The packets from the IAD are normal; however, packet loss occurs during the transmission
between the SBC and the UMG. The defense against UDP Flood attacks is enabled for the