Increasing TCP/IP maximum half open connection limit is known to boost P2P applications and accelerate torrent downloading, IObit has now came up with an P2P optimizer named P2PTurbo which allows you to tweak and optimize other TCP/IP and internet settings as well with ease.

P2PTurbo scans your computer, network settings and P2P network environment for accurate detection and optimization of bottlenecks slowing down your P2P connections, the utility supports most P2P Clients like BitTorrent, Limwire, Imesh, Morpheus, Ares Galaxy, Bitcomet, WarezP2P, DC++, eDonkey, eMule, BearShare, Kazaa, WinMX and Shareaza.

By default Windows XP allows a maximum of 10 half open connections at a time, this limit is implemented as a security feature to slow-down spreading of internet-worms in-case the user machine gets infected, if your network use is crossing this limit your computers event-log will show the following Event:

EventID 4226: TCP/IP has reached the security limit imposed on the number of concurrent TCP connect attempts.

This limit can slow down your internet access specially Peer-2-Peer applications like BitTorrent which require connecting to several peers for optimal performance, to increase this limit for speedy torrent downloading you need to patch the Windows TCP/IP system driver file, If your have already patched your TCPIP.sys file and updated your computer to Windows XP Service Pack 3, you should re-patch it using the free TCP/IP patcher for Windows XP.