Hi Stéphane,  take a look at the UAC module - it implements UAC authentication for SER:          http://www.voice-system.ro/docs/uac/  best regards,  Marian  Stéphane Muller wrote:  > Hi everybody,  >  > I would like to know if it is possible to forward a call to an external proxy/pstn-gateway  > that need authentication ?  >  > I have read in the archives that SER itself can't do that, but it is possible by interacting  > with sipsak... Is it correct ? And if yes, exactly how ?  >  > Thank's a bunch for any answer.  >  > Steph