If you feel like "looking for trouble", don't do it in Vicidial. LOL
Things you can check:
Admin->Servers
Verify your max trunks is within the limits of your available trunks (based on bandwidth or carrier limits)
Verify your calls per second is no more than 1 for every 10 agents (and try to stay under 5 unless you discuss it with your carrier, they get touchy about that).
/var/log
Check all your logs for all installed software for errors. Look them up if you find any to see if they are "actionable".
After that, you should consider turning off logging in Vicidial and Asterisk until you need to debug something (save processor and disk i/o).
Logging in Vicidial: Admin->Servers
Logging in Asterisk: /etc/asterisk/logger.conf
And check out Kumba's sticky of "best practices" (! What am I saying! Of course you've already done that ... because reading the stickies is required before posting
right?)