Here is the Carrier which is enabled. There are other carriers also setup in exactly same fashion (with obviously their IPs) which are disabled on the carrier setup page.
----------Excerpt from sip-vicidial.conf-----------
[vicidial-auto]
exten => h,1,DeadAGI(
agi://127.0.0.1:4577/call_log--HVcauses ... ----------)
; Local Server: 10.0.0.170
exten => _010*000*000*170*.,1,Goto(default,${EXTEN:16},1)
; VICIDIAL Carrier: KarNet - KarNet Comms
exten => _91NXXNXXXXXX,1,AGI(
agi://127.0.0.1:4577/call_log)
exten => _91NXXNXXXXXX,2,Dial(sip/${EXTEN:1}@karnet,55,o)
exten => _91NXXNXXXXXX,3,Hangup
----------Excerpt from extensions-vicidial.conf-----------
; VICIDIAL Carrier: KarNet - KarNet Comms
[karnet]
disallow=all
allow=ulaw
allow=gsm
type=peer
host=10.0.0.4
dtmfmode=rfc2833
qualify=yes
port=5060
nat=yes
canreinvite=no
fromdomain=10.0.0.170