Sometimes it can be difficult to determine the reason for a call failure even after having a SIP diagram extracted. An Admin user usually collects a TCP dump of a call while trying to reproduce the issue; in such a case, the Admin user should have access to the CLI (Command Line Interface) of the bare metal server where the Sippy softswitch is running. It is possible to use an external tool/device which shares the same network with the Softswitch; when this is so, that could itself create a barrier in the investigation process.
The Sippy softswitch provides a Web-interface tool with basic parameters which helps to collect a PCAP trace and forward it to an email address as an attachment. The tool is available at System Management --> Tools --> Network Traffic Capture.
The top of the page contains the options that should be filled in:
Target Hosts - contains the list of IP addresses that are going to be monitored. In the example below, the Traffic Capture will be gathering all packets coming from and to those five IP addresses.
The IP addresses can be separated by "new line", by "comma" or even by "comma + space".
Interface - an option to set the network interface and source IP address for TCP Dump to run at. There will be more than one option to choose if you have at least two IP address assigned to your Environment.
Duration, min - how long the Traffic Capture will run.
E-mail - an email address to send the collected PCAP file in the end. Several recipients are supported and should be separated by "comma".
Once all parameters are set, press the "Add" button to include the task into the queue:
In a minute, the system will start gathering the traffic and your task will change its status to "In Progress", which means Traffic Dump has started capturing packets on selected interface and IP address. If the test call is to be examined, it's the best time to start it.
Finally, when the dump is completed, the icon to download the trace will appear:
Note that traffic dumps are kept in the list for 48 hours. Thus, please make sure you downloaded a copy of the trace in order not to lose it in 2 days.
And its max size is the following:
MAXIMUM_DUMP_SIZE = 256 # megabytes