[REBOL] Re: timeout
From: athena:pop3-dfw:myfirstlink at: 10-Apr-2001 6:15
What you are attempting to do is open a TCP connection with a host on a
specific port. The open request is initiated by the application
(REBOL). Your TCP stack on your system actually handles the three way
handshake to open the connection. Without an "open" timeout in the
application, how long it takes for the open request to return to REBOL
depends upon how the remote host responds (assuming the host is there)
and timeout settings in the TCP stack. Some hosts will respond with an
ICMP message indicating the port is not available and that should be
very quick. Others may ignore the request in which case the TCP stack
timeout controls how long it will take to complete. UDP is another
story. Obviously, where actual communication occurs, network time
contributes to how long the open request takes.
There are also other ICMP messages the network may return which should
terminate the open request. If REBOL passes these status messages back,
assuming the TCP stack provides the reason for the failure to REBOL, you
may want to look at the error to decide what to do. For example if the
destination host is not available you don't need to go through a bunch
of connection attempts, because none of them will succeed.
And hopefully you are doing this program for a noble purpose. Internet
security people consider this type of program an indication of an
attempt to breach security--a hacker attack in progress.
Paul Tretter wrote: