[twsocket] timeout when tcp connection on internet

Wilfried Mestdagh wilfried_sonal@compuserve.com
Fri, 9 Jun 2000 14:37:59 +0200


I have a question about timeout when connected over internet. Situation is
as follwos (TCP connection):

LAN machine (client) -> cable modem -> ISP1 -> ISP2 -> router -> LAN machine

When there is no traffic for a few hours both programs sockets are still in
connected state, but if one of them is trying to send data it is never reach
and the connection is broken after a few minutes. So

I know I have to send keep-alive packets, but who does the timeout ?  Is it
the router, or something between the 2 internet providers ? If I run the
same configuration on a LAN there seems not a timout.

Does anybody know on what time interval I should send keep alive packets in
sutch a situation ?

Note that the machine connected with cable modem dus regulary gets dhcp
messages (lease expired and renewed) but it does not seem that is the reason
(trying to send immediatly after sutch a message does work).

thanks in advance, Wilfried