> I think all modern implementations will always send ACK on an established > connection, but I don't think RFC793 requires it. Therefore, it may be safe to > drop unflagged packets, but it seems like a bad idea to me. ACK on everything? That does not sound right. When I call send(fd, ..., "some message"), I'd expect - a non-ack packet from me->remote - an ack packet from remote Jan Engelhardt -- | Gesellschaft fuer Wissenschaftliche Datenverarbeitung Goettingen, | Am Fassberg, 37077 Goettingen, www.gwdg.de