I was often seeing something like
— Got SIP response 500 “Internal Server Error” back from 192.168.0.10
on my asterisk server. Actually, its running the trixbox installation but asterisk is the application reporting the errors.
While running polycom firmware up to 2.1.1 this error appears. If you change to 2.1.2, the error goes away.
It appears that its come back. After a particularly nasty asterisk crash, im getting these errors again.