The following configuration settings worked fine for me:
sip.conf
type=peer
secret=your-secret
auth=md5
username=7xxxxx
host=sip.neophonex.hu
fromuser=7xxxxx
fromdomain=sip.neophonex.hu
nat=no
insecure=very
context=sip-incoming
callerid=7xxxxx
disallow=all
allow=ulaw
allow=alaw
allow=ilbc
For some strange reasons, NeoPhoneX’s SIP Express Router dials 10069s as your dialin number, instead of s.
extensions.conf
OUT_SIP=SIP/NeoPhoneX
[sip-incoming]
exten => 10069s,1,Macro(stdexten,XX,SIP/XX)
exten => 10069s,2,Hangup
[sip-pstn]
exten => _06xxxxxxx.,1,Dial(${OUT_SIP}/${EXTEN})
exten => _06xxxxxxx.,2,Congestion)
exten => _06xxxxxxx.,3,Hangup
[macro-stdexten]
exten => s,1,Dial(${ARG2},20,tT)
exten => s,2,Voicemail(u${ARG1})
exten => s,3,Hangup
exten => s,102,Voicemail(b${ARG1})
exten => s,103,Hangup