17 Jun
2010
17 Jun
'10
6:35 p.m.
On Jun 17, 2010, at 12:59 PM, Maarten ter Huurne wrote:
Maybe it uses UPNP to tell the router which ports to open?
As far as I know, there are no hole-punching techniques for TCP like there are for UDP. So the only way to get a port forward is to configure the router, manually or through an API like UPNP.
Yes, many bittorrent clients use UPNP and/or NAT-PMP to open a hole in the firewall. This will work for most users of home routers, but not other NAT scenarios. I'm just waiting for the kernel patch which makes socket()/bind() automatically send a UPNP/NAT-PMP to the router to open the port. :) James