This tool is used to allow admin to collect data while reproducing the issue to find out why the issue is happening. In repro mode we have different templates please refer to my ISA data packager . We choose different templates depending upon the scenario/issue we are facing in following example web proxy and web publishing template is being used as we had a web publishing issue , however it can also be used in forward proxy scenario.
similarly Vpn template can be used for vpn issues.
If you refer to my ISA data packager post you will notice that you can modify options and check and uncheck various options depending upon what type of data you want to collect and how much buffer size you want to keep e.g. network monitor and in advanced options buffer for ISAtracing logs(default is 400).