Firstly save the resulting file as a .tar /.rar and use 7zip or winrar to extract. This will produce four .tar.gz files (e.g. systeminformation.tar.gz) which can be subsequently extracted. However the core telephony logs will be largly hex, so you won't be able to interpret them. Whereas the feps.log will give some call signalling details on call set up and tear down for voip gateway, if you are sending the call across a voip (h323 or sip) trunk and having a problem, rather than just an incoming call from ISDN (PRI or BRI).
Before delving into the logs, please define what call disconnect issues you are experiencing and the type of lines. For example are you using a DTM (Euro PRI). You can more easily check Alarms within BCM element manager and look for any alarms that coincide with call problems....such as alarm 75 clock in free run. Assuming you are using a DTM (PRI) check the clocking is set to primary external, refer to docs for full details. If BRI only, check the loops are primary external. Refer to docs if > one PRI or BRI. A DTM must be installed in the main unit on a 400, not in an expansion unit.
Try simplifying the problem too, such as try calling into digital BST/TDM sets, rather than IP sets, from Central Office/PSTN, so you don't use the customers data network.
There has been some recent patches which resolve with intermittent calls not being answered on analogue lines, however this may apply to other line types. So perhaps pursue the latest patches/system service update (after taking a backup of course).
Hope this helps.
