VoIP Ethernet Capture TMG3200
This article applies to: | Product | Version |
Tmedia | 2.8, 2.9, 2.10, 3.0, 3.2 |
Capturing using the TMG3200's internal host
The TMG3200's internal host can be used for capturing packets that are mirrored from the VOIP0 and/or VOIP1 physical ports. This includes RTP traffic.
Preparing the Tmedia for capture
- If the traffic to be captured is on a VLAN, then an IP Interface with the services "MANAGEMENT" must be created.
- The IP has to be static and on the same network as the one to capture.
- The virtual port assigned must be the same as the port to capture. See IP Interface.
- The IP has to be static and on the same network as the one to capture.
Start Capture
You need two SSH sessions to capture the traffic:
First, access the Tmedia management interface using SSH. Then, access the telecom baseboard using
telnet 172.31.1.1
Prompt is now:
0/tbgw>
To capture VoIP0 traffic:
mv88eMonitor 0x4 0x4 8 600
To capture VoIP1 traffic:
mv88eMonitor 0x8 0x8 8 600
In the example the duration is 600 seconds, thus will capture traffic for 10 minutes.
Note: We don't recommend to keep the capturing for a long time. This is only for debugging purpose.
Second, access the Tmedia management interface using SSH
Prompt is now:
[root@TBxxxxxx ~]#
To dump the content of the VOIP traffic in the file voip_capture.cap
if the VOIP traffic is untagged:
tcpdump -i int0 -s 1500 -w voip_capture.cap
If the traffic is tagged, use the name of the IP interface created previously (for example vlan333)
tcpdump -i vlan333 -s 1500 -w voip_capture.cap
You will see something like this:
tcpdump: listening on mgmt0, link-type EN10MB (Ethernet), capture size 1500 bytes
Stop Capture
When you're ready, stop the capture by pressing control-C on the shell that was running tcpdump command
You will see something like this:
364 packets captured 590 packets received by filter 0 packets dropped by kernel
- Access the telecom baseboard from the Tmedia using telnet.
telnet 172.31.1.1
- Stop the capture
mv88eMonitor 0 0 0
Download Capture
To download the voip_capture.cap file, use SSH secure copy ("sftp") to the Tmedia management port. This can be done on Windows using tools like Filezilla or WinSCP.
The file will be located in
/root