Here is a list services running on the host system where chroot operates as Virtual PBX and relative ports (make sure these ports are not occupied):

53 dnsmasq
67 dhcp
68 dhcp
80 tproxyd
81 lighttpd (localhost)
389 slapd
443 tproxyd
444 lighttpd (localhost)
1025 memcached (localhost)
1027 rtpengine (localhost)
2222 sshd
2812 monit
3306 mysqld (localhost)
3478 turnserver (localhost)
4200 shellinaboxd (localhost)
4369 epmd
5039 callweaver (localhost)
5060 kamailio (localhost)
5061 kamailio (localhost)
5222 beam
5223 beam
5269 beam
5280 beam
5766 turnserver (localhost)
6789 beam
7008 smsd
42764 beam