root@turing:/etc/bind# cat db.voixtel.internal 
$TTL 3D
@       IN      SOA    turing.voixtel.com.br. root.voixtel.com.br. (
                       200705062       ; serial#
                       3600            ; refresh, seconds
                       3600            ; retry, seconds
                       3600            ; expire, seconds
                       3600 )          ; minimum TTL, seconds

                NS     localhost

IN              MX      10  200.234.203.6
turing          A       192.168.0.254
matrix          A       192.168.0.110
pop             A       200.234.205.191

voixtel.com.br.     IN      NAPTR   2 0 "s" "SIP+D2T" "" _sip._tcp.voixtel.com.br.
voixtel.com.br.     IN      NAPTR   2 0 "s" "SIP+D2U" "" _sip._udp.voixtel.com.br.

_sip._udp       SRV    100     1       5060    matrix
_sip._tcp       SRV    200     1       5060    matrix
_sips._tcp      SRV    300     1       5060    matrix