IPO/Asterisk SIP Trunk 503 service unavailable

[korexxkun]

Im trying to connect an IPO server edition to Asterisk

checking trace...
when i dial from IPO to asterisk i get no trace at all
when i dial from asterisk to IPO we get 503: service unavailable (unable to reach server), the phone displays declined temporarily


23/02/15 09:09:11-496ms Line = 4, Channel = 1, SIP Message = Response, Direction = From Switch, From = 62916@sip.fcmb.com, To = 2737@172.27.13.61, Response = 503 Service Unavailable
23/02/15 09:09:11-497ms Line = 4, Channel = 1, SIP Message = Ack, Direction = To Switch, From = 62916@sip.fcmb.com, To = 2737@172.27.13.61


I followed the following

ITSP Domain: Asterisks IP
IPSP IP : Asterisks IP
Registration Required : checked
In Service : Checked
Everything else : <leave default>

SIP URI
Add a new channel as below.
Local URI : Use internal Data
Contact : : Use internal Data
Display Name : Use internal Data
Incoming Group : 4
Outgoing Group : 4

Short Code : Code : 6XXXX
Telefon Number : 6N"@Asterisk IP"
Line Group Id : Same as Outgoing Group as above
Rest is default.

Incoming Call Route :
Bearer Capability : Any Voice
Line Group ID : Same as Incoming Group as above

Destinations;
Time Profile : Default Value
Destination : . (dot)