helptext=>Activate Call Forwarding on an ISDN port
usage=>Port = [1-12],ServedUserNumber = [phone-number],ForwardedToNumber= [phone-number], ServedUserNumberTon = [integer] (optional), ForwardedToNumberTon = [integer] (optional - ServedUserNumberTon has to be provided too)
example=>&Port=1&ServedUserNumber=030259389776&ForwardedToNumber=030259389777,&Port=1&ServedUserNumber=030259389776&ForwardedToNumber=030259389777&ServedUserNumberTon=0&ForwardedToNumberTon=0
return=>success:String result of Operation
