Hello, friend!
Today I'm going to share with you when the network packet loss causes users sometimes to pick up the phone without a dial tone. Pots cannot be used normally.
Problem Description
Networking: UA5000-MA5680T-3252-7750-Softswitch
Trouble phenomenon: Sometimes when UA5000 users pick up the phone, there is no dial tone and only current, which can automatically recover after a period of time.
Warning message
ALARM 3918 Operation information Warning 0x1c100008 Service quality 2009-11-09 01:53
Alarm name: QOS exceeds the threshold alarm recovery
Parameter information: Channel: 0/0/15 (board number [0-main board1-backup board]/subboard number/channel number),
Peer IP: 10.37.7.189, loop delay: 5 (ms), packet loss rate: 1 (percent), jitter: 0 (
millisecond)
Alarm description: QOS exceeds the threshold alarm recovery
Alarm reason: the network is normal, etc.
Repair suggestions: None
--- END
ALARM 3917 Operation Information Warning 0x1c100007 Service Quality 2009-11-09 01:53
Alarm name: QoS exceeds the threshold
Parameter information: Channel: 0/0/15 (board number [0-main board1-backup board]/subboard number/channel number),
Peer IP: 10.37.7.189, loop delay: 4 (ms), packet loss rate: 13 (percent), jitter: 0
(millisecond)
Alarm description: QOS exceeds the threshold
Alarm reason: the bearer network is busy, abnormal, etc.
Repair suggestion: Check the bearer network or increase network capacity
--- END
Process
1. View historical alarm information. There is no DSP chip failure alarm and DSP resource allocation is normal.
2. Intermittent packet loss when pinging Softswitch from UA5000
The reply comes from 10.37.3.103: Byte count=56 Sequence number=999 Time to live=28 Time=2 milliseconds
--- 10.37.3.103 Ping statistics ---
1000 transmission packets
999 Number of packets received
0.10% packet loss
Return time Min/Average/Maximum = 2/2/5 ms
3. When the packet capture analysis on the UA5000 side fails, the user has not been released by the Softswitch and is still in the previous association. As a result, the softswitch does not issue a dial tone when the user picks up the phone. It is suspected that the last call before the failure was caused by packet loss. The loss of the detection event after the user hangs up causes the inconsistency of the port status on the soft switch and the AG side.
After changing the transmission mode to ALF/UDP and fixed retransmission mode on the UA5000, the problem has been significantly improved. The specific operation method is as follows:
VOICE(config-if-h248-0)#if-h248 attribute transfer alf/udp
VOICE(config-if-h248-0)#h248stack tr retransmode fixed 1000
Root cause
1. Network packet loss.
2. DSP subboard resource allocation is faulty.
Conclusions
For the alarm failure of packet loss in the network, the first thing to think about is how to solve the network problem. Intermittent packet loss and the redundant transmission method of the device can be solved when the packet loss is not very serious. However, it is necessary to solve the problem fundamentally. Solve network problems.
You are welcome to leave a message and exchange in the comment area.
Thank you!
