anchor.diff:  %%
   %% Anything except CANCEL or BYE
   %%
  -relay_request_to_pstn(THandler, Request, DstURI, DstNumber, LogTag) when record(Request, request) ->
  +relay_request_to_pstn(THandler, Request, DstURI, DstNumber, LogTag) when is_record(Request, request) ->
       {Method, Header} = {Request#request.method, Request#request.header},
       {_, FromURI} = sipheader:from(Header),
       Classdefs = sipserver:get_env(classdefs, [{"", unknown}]),
  
positive.code:     NewRequest = Request#request{header=NewHeaders3},
      THandler = transactionlayer:get_handler_for_request(Request),
      relay_request_to_pstn(THandler, NewRequest, NewURI, DstNumber, LogTag).
  
  
  %%--------------------------------------------------------------------
  
negative.code: %%           one and make it so.
  %% Returns : Does not matter
  %%--------------------------------------------------------------------
  request_to_pstn(Request, Origin, THandler, LogTag) when is_record(Request, request), is_record(Origin, siporigin) ->
      {Method, URI, Header} = {Request#request.method, Request#request.uri, Request#request.header},
      {DstNumber, ToHost} = {URI#sipurl.user, URI#sipurl.host},
      %% XXX check port to, not just hostname? Maybe not since pstnproxy by definition
  