I think I've found out why the TCP hangs: someone messes with TCP sequence numbers and get them wrong.
I studied some advanced features of TCP, and discovered the existence of "selective acknowledgment" (SACK), which is a very nice feature, by the way. By comparing packets at the two ends of the connection, it is clear that sequence numbers are rewritten in the standard TCP header, but not in the SACK option. This should be a good way to confuse the TCP stack at the sender side and break the connection. I suspect my ISP (which does NAT), but I have to do some more experiments to be sure. Thanks for the suggestions I received. Bernardo -- To UNSUBSCRIBE, email to [EMAIL PROTECTED] with a subject of "unsubscribe". Trouble? Contact [EMAIL PROTECTED]
