[Dovecot] auth on tcp socket?

Hello,

is it possible to provide service auth on tcp-socket instead of unix-socket? I changed my conf and dovecot 2.0.5 is restarting but on telnet test it throws: dovecot: auth: Fatal: getsockname(12) failed: Socket operation on non-socket

Want to separate smtp and imap to different servers but keep using dovecot auth for postfix-sasl. Whats to do? hmm, is postfix able to use non-unix socket for dovecot-sasl?

Thanks, Hajo