This FreeBSD port has been designed for FreeBSD 6 and 7. It’s currently a 1.2rc4, snapshots will follow.

http://www.freebsd.org/cgi/query-pr.cgi?pr=115087

# mkdir -p /usr/ports/net/callweaver
# cd /usr/ports/net/callweaver
# ftp <shar-1.sh from one of the PRs>
# sh shar-1.sh
# make config install (clean)