I don't think you'll get much help here. Usually we frown about P2P file sharing, because too often it leads to illegal things like sharing (transmitting to others) copyrighted content.
My main computer's (XP, SP3) Internet connection is shared among 3 other machines via ICS. However, one machine (XP, SP3) - which runs a couple of P2P programs - usually loses its connectivity (even file sharing) after a few days.
I'm running Kaspersky Internet Security on the main computer. I've tried disabling it (for testing purposes) to no avail. I've also disabled Windows Firewall on both machines with no improvement. Using a router is pointless because it freezes after a few days (due to the P2P programs). I've tried 4 or 5 different routers (even the "good" brands).
Is it simply an overload in terms of the number of connections possible? Does ICS, in principle, face the same problems as a typical router? Because I've even tried reducing the number of P2P programs to just one and also limiting the number of connections it makes. (Not to mention "fixing" the 'tcpip.sys' limit on both machines.) Any ideas what the problem could be and how to fix it? Thanks.