code: private SipURI getAOR(final SipRequest request) {
          final SipURI sipURI = (SipURI) request.getToHeader().getAddress().getURI();
          return SipURI.with().user(sipURI.getUser()).host(sipURI.getHost()).build();
      }
docs: The To-header contains the AOR (address-of-record) that the user wish to associate with the
  contact information in the Contact-header. We must also convert the To-header into its
  canonical form, which is the aor we will use as the key into the existing bindings.
  
  @param request
  @return