anchor.diff:  	AccessReject = radius_attributes:codec(AccessRejectData),
   	{ok, "Unknown Username"} = radius_attributes:find(?ReplyMessage, AccessReject).
   
  +unknown_username_diameter() ->
  +	[{userdata, [{doc, "Diameter simple authentication failure wheh a unknown username is used"}]}].
  +
  +unknown_username_diameter(Config) ->
  +	UnknownUsername = "PeterGriffin",
  +	Password = ?config(password, Config),
  +	SId = diameter:session_id(atom_to_list(?FUNCTION_NAME)),
  +	NAS_AAR = #diameter_nas_app_AAR{'Session-Id' = SId,
  +			'Auth-Application-Id' = ?NAS_APPLICATION_ID ,
  +			'Auth-Request-Type' = ?'DIAMETER_NAS_APP_AUTH-REQUEST-TYPE_AUTHENTICATE_ONLY',
  +			'User-Name' = UnknownUsername, 'User-Password' = Password},
  +erlang:display({xxxxxx, ?MODULE, ?FUNCTION_NAME, ?LINE, NAS_AAR}),
  +	{ok, Answer} = diameter:call(?SVC, nas_app_test, NAS_AAR, []),
  +	true = is_record(Answer, diameter_nas_app_AAA),
  +	OriginHost = list_to_binary("ocs.sigscale.com"),
  +	OriginRealm = list_to_binary("sigscale.com"),
  +	#diameter_nas_app_AAA{'Result-Code' = ?'DIAMETER_BASE_RESULT-CODE_AUTHENTICATION_REJECTED',
  +			'Auth-Application-Id' = ?NAS_APPLICATION_ID,
  +			'Auth-Request-Type' = ?'DIAMETER_NAS_APP_AUTH-REQUEST-TYPE_AUTHENTICATE_ONLY',
  +	'Origin-Host' = OriginHost, 'Origin-Realm' = OriginRealm} = Answer.
  +
   %%--------------------------------------------------------------------------------------
   %% Internal functions
   %%--------------------------------------------------------------------------------------
  
positive.code: %% Cleanup after each test case.
  %%
  end_per_testcase(TestCase, Config) when
  		TestCase == simple_authentication_diameter; TestCase == bad_password_diameter ->
  	UserName= ?config(username, Config),
  	Client = ?config(diameter_client, Config),
  	ok = ocs:delete_client(Client),
  
negative.code: %% Initiation before each test case.
  %%
  init_per_testcase(TestCase, Config) when
  		TestCase == simple_authentication_diameter; TestCase == bad_password_diameter;
  		TestCase == unknown_username_diameter ->
  	UserName = "Wentworth",
  	Password = "53cr37",
  	{ok, [{auth, AuthInstance}, {acct, _}]} = application:get_env(ocs, diameter),
  