http://wiki.mikrotik.com/wiki/Voip

# mar/02/2010 01:05:55 by RouterOS 3.20
# software id = T06M-LTT
#
/ip firewall connection tracking
set enabled=no generic-timeout=10m icmp-timeout=10s tcp-close-timeout=10s \
    tcp-close-wait-timeout=10s tcp-established-timeout=1d \
    tcp-fin-wait-timeout=10s tcp-last-ack-timeout=10s \
    tcp-syn-received-timeout=5s tcp-syn-sent-timeout=5s tcp-syncookie=no \
    tcp-time-wait-timeout=10s udp-stream-timeout=3m udp-timeout=10s
/ip firewall filter
add action=drop chain=forward comment="" disabled=no dst-port=445 protocol=\
    tcp
add action=drop chain=forward comment="" disabled=no dst-port=135-139 \
    protocol=tcp
/ip firewall mangle
add action=mark-packet chain=prerouting comment=OSPF disabled=no \
    new-packet-mark=ospf passthrough=no protocol=ospf
add action=mark-packet chain=prerouting comment=ICMP disabled=no \
    new-packet-mark=icmp passthrough=no protocol=icmp
add action=mark-packet chain=prerouting comment="Small Packets" disabled=no \
    new-packet-mark=small packet-size=0-256 passthrough=no
add action=mark-packet chain=prerouting comment="Large Packets" disabled=no \
    new-packet-mark=large packet-size=257-1550 passthrough=no
/ip firewall nat
add action=src-nat chain=srcnat comment="SRCNAT PPPoE clients on IC->WS" \
    disabled=no out-interface=ether1 src-address=10.255.255.0/24 \
    to-addresses=208.66.121.18
/ip firewall service-port
set ftp disabled=no ports=21
set tftp disabled=no ports=69
set irc disabled=no ports=6667
set h323 disabled=no
set sip disabled=no ports=5060,5061
set pptp disabled=no

# mar/02/2010 01:03:01 by RouterOS 3.20
# software id = T06M-LTT
#
/queue type
set default kind=pfifo name=default pfifo-limit=50
set ethernet-default kind=pfifo name=ethernet-default pfifo-limit=50
set wireless-default kind=sfq name=wireless-default sfq-allot=1514 \
    sfq-perturb=5
set synchronous-default kind=red name=synchronous-default red-avg-packet=1000 \
    red-burst=20 red-limit=60 red-max-threshold=50 red-min-threshold=10
set hotspot-default kind=sfq name=hotspot-default sfq-allot=1514 sfq-perturb=\
    5
set default-small kind=pfifo name=default-small pfifo-limit=10
/queue tree
add burst-limit=0 burst-threshold=0 burst-time=0s disabled=no limit-at=0 \
    max-limit=0 name=GLOBAL packet-mark="" parent=global-in priority=8 queue=\
    default
add burst-limit=0 burst-threshold=0 burst-time=0s disabled=no limit-at=0 \
    max-limit=0 name=PRIO-1 packet-mark="" parent=GLOBAL priority=1 queue=\
    default
add burst-limit=0 burst-threshold=0 burst-time=0s disabled=no limit-at=0 \
    max-limit=0 name=OSPF packet-mark=ospf parent=PRIO-1 priority=1 queue=\
    default
add burst-limit=0 burst-threshold=0 burst-time=0s disabled=no limit-at=0 \
    max-limit=0 name=ICMP packet-mark=icmp parent=PRIO-1 priority=2 queue=\
    default
add burst-limit=0 burst-threshold=0 burst-time=0s disabled=no limit-at=0 \
    max-limit=0 name=TCPACK packet-mark=tcpack parent=PRIO-1 priority=3 \
    queue=default
add burst-limit=0 burst-threshold=0 burst-time=0s disabled=no limit-at=0 \
    max-limit=0 name=PRIO-2 packet-mark="" parent=GLOBAL priority=2 queue=\
    default
add burst-limit=0 burst-threshold=0 burst-time=0s disabled=no limit-at=0 \
    max-limit=0 name=SMALL packet-mark=small parent=PRIO-2 priority=2 queue=\
    default
add burst-limit=0 burst-threshold=0 burst-time=0s disabled=no limit-at=0 \
    max-limit=0 name=LARGE packet-mark=large parent=PRIO-2 priority=4 queue=\
    default
/queue interface
set ether1 queue=ethernet-default
set ether2 queue=ethernet-default
set ether3 queue=ethernet-default
set LOOPBACK queue=default