ipc send problem

Hello. I have some c++ code


     int sock = nn_socket(AF_SP, NN_PAIR);
     assert(sock>=0);
     assert(nn_connect(sock, URL)>=0);
     int to = 100;
     assert (nn_setsockopt (sock, NN_SOL_SOCKET, NN_RCVTIMEO, &to, sizeof (to)) >= 0);
     UE_LOG(LogClass, Log, TEXT("___SET SOCK OPTION___"));
     int sz_n = strlen (msg) + 1; // '\0'
     printf ("%d
", sz_n);
     int bytes = nn_send (sock, msg, sz_n, 0);
     printf ("%d
", bytes);
     assert(bytes >= 0 );

and I have application ( actually it is a node.js local server using nanomsg libs for communication between game clinet)

If I call this code from standart c++ console application - everything is worked true, but if i call from ue4 project - i get delay for nn_send. What is my problem?

ps I want to use UE4 TCP to connect between Unreal game client and my application running in the same host.
Does Unreal has blocking any TCP ports or not?
Best regards