try this config.
controller E1 1/0
pri-group timeslots 1-31
!
!
interface Serial1/0:15
no ip address
encapsulation hdlc
no logging event link-status
isdn switch-type primary-net5
isdn overlap-receiving T302 5000
isdn protocol-emulate network
isdn incoming-voice voice
isdn T310 60000
isdn send-alerting
isdn sending-complete
isdn incoming alerting add-PI
no cdp enable
!
!
voice-port 1/0:15
echo-cancel coverage 32
echo-cancel suppressor
timeouts interdigit 3
!
!
dial-peer voice 9 voip
destination-pattern 0T
translate-outgoing called 1
voice-class codec 1
session target ipv4:144.44.205.100
dtmf-relay h245-alphanumeric
fax protocol t38 ls-redundancy 0 hs-redundancy 0 fallback cisco
ip qos dscp cs5 media
no vad
!
dial-peer voice 8 pots
destination-pattern 0T
direct-inward-dial
port 1/0:15