Callcentric asterisk openbts configuration

I run asterisk with open bts project but no any outcome calls, what is the problem?? this is my sip file
[general]
; Comment these out if no backhaul is available.

dtmfmode = rfc2833
context=from-callcentric
srvlookup=yes
register => 1777*******:@callcentric.com/1777*******
session-timers=refuse

[callcentric]
type=peer
context=from-callcentric
host=callcentric.com
username=1777*******
secret=
fromuser=1777*******
fromdomain=callcentric.com
insecure=very

[SIPTestPhone]
;callerid=2101
canreinvite=no
type=friend
context=sip-external
allow=ulaw
allow=gsm
host=dynamic

; This is a GSM handset entry.
; You need one for each SIM.
; The IMSI is a 15-digit code in the SIM.
; You can see it in the Control log whenever a phone tries to register.

[IMSI3] ; <- The IMSI is used as a SIP user ID.
username=IMSI
3
type=friend
context=to-callcentric
disallow=all
allow=gsm
host=dynamic

and this extenstion i only need outbound call:
[to-callcentric]
exten => _X.,1,Dial(SIP/${EXTEN}@callcentric)

Verbose CLI traces and sip set debug on output!

radwa-laptopCLI> sip show registry
Host dnsmgr Username Refresh State Reg.Time
0 SIP registrations.
radwa-laptop
CLI> sip show peers
Name/username Host Dyn Nat ACL Port Status
IMSI6*********3/IMSI6 127.0.0.1 D 5062 Unmonitored
IMSI602******90 (Unspecified) D 5060 Unmonitored
SIPTestPhone (Unspecified) D 5060 Unmonitored
sip (Unspecified) D 5060 Unmonitored
4 sip peers [Monitored: 0 online, 0 offline Unmonitored: 4 online, 0 offline]