Prioritize Asterisk Process
You can experiment with different values and see what works best. I wouldn't go too high as it could cause other problems. From the command 'top' the PR column shows absolute priority and NI column is the relative number we add here. Default is 0 which gives Asterisk about the same default priority as httpd and mysql. 5-10 should give top priority without crippling critical background tasks. I believe this setting can go as high as 20. This is only a prioritization recommendation setting. The linux process scheduler still has ultimate authority so actual priority will vary from system to system depending on what else is installed.
nano +22 /usr/sbin/safe_asterisk
PRIORITY=10