Thank you for reply. Is it possible to adjust the timeout on tcp level for current tcp connection?
2013/3/27 Ludo Brands <ludo.bra...@free.fr>: > On 03/27/2013 01:00 PM, Oleg Kurchenko wrote: >> Hello, >> >> it seems that communicating, described in >> http://www.ararat.cz/synapse/doku.php/public:howto:activeconnection >> does not help. >> >> I made a simple demo of tcp client, the code is shown below. >> >> After I connected to server and took out the LAN cable and there is a >> red cross on the connection icon in the system tray, I can for about >> 30 seconds to send messages, and it does not get errors! >> >> >> Can this be fixed? >> > > No. TCP is a protocol designed to work on unreliable communication links > and will recover from errors. So a broken link is not immediately an > error on the TCP layer. There are timeouts that make that TCP will > consider a link dead after a certain delay. > > The red cross on the connection icon you are seeing is on a completely > different layer of the network protocol (physical layer) and has nothing > to do with TCP. In more complex configurations you can pull out a cable > and communication will just go on over a different link without the TCP > communication ever being broken down. A nice example is wifi roaming. > > So if you need to know when a network cable is pulled out, you need to > use a different method. Ping your local router (ICMP is not using TCP) > with a short timeout (mind alternate routes!) or get your network card > status using some OS dependent calls. > > Ludo > > ------------------------------------------------------------------------------ > Own the Future-Intel® Level Up Game Demo Contest 2013 > Rise to greatness in Intel's independent game demo contest. > Compete for recognition, cash, and the chance to get your game > on Steam. $5K grand prize plus 10 genre and skill prizes. > Submit your demo by 6/6/13. http://p.sf.net/sfu/intel_levelupd2d > _______________________________________________ > synalist-public mailing list > synalist-public@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/synalist-public ------------------------------------------------------------------------------ Own the Future-Intel® Level Up Game Demo Contest 2013 Rise to greatness in Intel's independent game demo contest. Compete for recognition, cash, and the chance to get your game on Steam. $5K grand prize plus 10 genre and skill prizes. Submit your demo by 6/6/13. http://p.sf.net/sfu/intel_levelupd2d _______________________________________________ synalist-public mailing list synalist-public@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/synalist-public
