just checked wiki
ECHO protocol
From Wikipedia, the free encyclopedia
The ECHO service is an internet protocol defined in RFC 862. It was
originally proposed as a way to test and measure an IP
network
A host may connect to a server that
supports the ECHO protocol on either TCP or UDP port 7. The server
then sends back any data it receives, with no modification by the
echo server.
delete the file if u not using it?