TCP / IP communication of RHEL 7 is extremely slow compared with RHEL 6 and earlier.

TCP / IP communication of RHEL 7 is extremely slow compared with RHEL 6 and earlier.
My application transferd from RHEL 5 to RHEL 7.
That application makes TCP / IP communication with another application on the same server.
That communication speed is about twice slower.

Apart from that, we compared it with "ping localhost". RHEL 7 averaged 0.04 ms, RHEL 6 and RHEL 5 average 0.02 ms. RHEL 7 is twice as slow as RHEL 6 or earlier.

The environment is the minimum installation, stop firewalld and postfix, then do "ping localhost".

Why was communication delayed like this?
Or, what is going on late?
Is not it worth it?