Please note the screenshot. I have an Ubuntu 12.10 box running Asterisk. I ssh'ed into the server the other day to find asterisk running at 100% CPU on one core, and i watched it for several days now, and it is always at 100% cpu on one core. I did some extensive google searching to find other people with the same problem and not very many similar situations like mine. Ideally i would like it to use multiple cores or perhaps just not 100% cpu as i assume this is the reason why i am having quality issues with the lines.
I do not know how to even start to troubleshooting this, does anyone have any ideas?
edit: (Additional info from PBX Admin)
System sees 20-40 active channels on average. All inbound SIP, no transcoding (except mix_monitor on all calls for recordings, which transcodes to gsm), g711ulaw 8kHz.
result of "core show threads" here: http://pastebin.com/n26V5LPE
htop shows asterisk thread (PID 1745) at 106% CPU (main thread it seems).
Quad-core with hyperthreading. Uptime 45 days.
Same behavior with verbosity/debug at levels 0 and 6.
Phone system downtime scheduled soon for lots of little bug fixes and tuneups. Any help is greatly appreciated!