asterisk and blacklistd or alternative

[Mayuresh <mayuresh%acm.org@localhost>]

Would have been nice to have a blacklistd patch for asterisk, but guess
that must be pretty involved...

What alternatives are suitable (fail2ban? what else?) that work on log
files to block ips? Anything particularly suitable or particularly
unsuitable for asterisk? Or are custom scripts that track the logs are
a simpler idea?

Mayuresh