The Accept-Language header field is used in requests to indicate the
preferred languages for reason phrases, session descriptions, or
status responses carried as message bodies in the response.
This interface provides factory methods that allow an application to create
Address objects, URI's, SipURI's and TelURL's from a particular
implementation of this specification.
This method registers the SipListener object to this SipProvider, once
registered the SIP Listener can send events on the SipProvider and
recieve events emitted from the SipProvider.
The Authorization header is used when a user agent wishes to authenticate
itself with a server - usually, but not necessarily, after receiving an
UNAUTHORIZED Response - by including an AuthorizationHeader with the
Request.