Unknown open ports

[Ron Rademaker <ron@wep.tudelft.nl>]

I've just run a portscan to my computer that is connected to the internet
(permanently) and there were a few ports open of which I don't know what
they are for (all ports under 1024) and neither did the portscanner, these
are the ports: 686 698 708
If I use telnet to go to one of those ports, the connection isn't closed
by the remote host (only after I've typed a few things and pressed enter a
few times).

Anybody got any ideas on what these ports are for?

Ron Rademaker