is somebody attending, that wants to share his outgoing dial rules of extension.conf, like used in typical(?) german pbx setups?
* zero prefix for outside calls
* zero zero or plus prefix for international calls
* handle emergency calls
With ISDN, one was able to just forward the called number, but with sip, one has to normalize the dialed pattern in order to match SIP (provider)
expectations… As always, the devil is in the details.