anchor.diff:                     ?TT(?SECS(20)),
                      InitState = #{domain => inet6,
                                    proto  => tcp,
  +                                 msg    => Msg,
  +                                 num    => Num},
  +                   ok = traffic_ping_pong_sendmsg_and_recvmsg_tcp(InitState)
  +           end).
  +
  +
  +%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
  +%% This test case is intended to test that the sendmsg and recvmsg functions
  +%% by repeatedly sending a meassage between two entities.
  +%% The same basic test case is used for three different message sizes; 
  +%% small (8 bytes), medium (8K) and large (8M).
  +%% The message is sent from A to B and then back again. This is 
  +%% repeated a set number of times (more times the small the message).
  +%% This is the 'medium' message test case, for Unix Domain (stream) socket.
  +
  +traffic_ping_pong_medium_sendmsg_and_recvmsg_tcpL(suite) ->
  +    [];
  +traffic_ping_pong_medium_sendmsg_and_recvmsg_tcpL(doc) ->
  +    [];
  +traffic_ping_pong_medium_sendmsg_and_recvmsg_tcpL(_Config) when is_list(_Config) ->
  +    Msg = l2b(?TPP_MEDIUM),
  +    Num = ?TPP_MEDIUM_NUM,
  +    tc_try(traffic_ping_pong_medium_sendmsg_and_recvmsg_tcpL,
  +           fun() -> has_support_unix_domain_socket() end,
  +           fun() ->
  +                   ?TT(?SECS(20)),
  +                   InitState = #{domain => local,
  +                                 proto  => default,
                                    msg    => Msg,
                                    num    => Num},
                      ok = traffic_ping_pong_sendmsg_and_recvmsg_tcp(InitState)
  
positive.code:      traffic_ping_pong_small_sendmsg_and_recvmsg_tcpL,
       traffic_ping_pong_medium_sendmsg_and_recvmsg_tcp4,
       traffic_ping_pong_medium_sendmsg_and_recvmsg_tcp6,
       traffic_ping_pong_large_sendmsg_and_recvmsg_tcp4,
       traffic_ping_pong_large_sendmsg_and_recvmsg_tcp6,
  
  
negative.code:          traffic_ping_pong_small_sendmsg_and_recvmsg_tcpL/1,
           traffic_ping_pong_medium_sendmsg_and_recvmsg_tcp4/1,
           traffic_ping_pong_medium_sendmsg_and_recvmsg_tcp6/1,
           traffic_ping_pong_medium_sendmsg_and_recvmsg_tcpL/1,
           traffic_ping_pong_large_sendmsg_and_recvmsg_tcp4/1,
           traffic_ping_pong_large_sendmsg_and_recvmsg_tcp6/1,
  
  