yeah the only thing different are the private ips and the record-route
headers.

the carrier needs a special request thats why the +e164 to and e164
everywhere else and the <prefix>e164 in invite header.

if i start the call directly from freeswitch to the carrier (without
kamailio proxy) it works.

so i think maybe (as this is our main carrier) i need some other way to
solve that.

Best regards
Christoph