Hi, many thanks to all who have replied. So let me just summarize all these. The responds (particularly Jerry and Davi) describes that case where given a server with two open sessions (from two different clients), the dst_ip and dst_port (belong to the server) are the same. Now, if we 'reverse' the case (which was what I'm interested initially, so my original question fails to put across this intention), the case become: a client have 2 TCP sessions to two different servers. In both sessions, src_port (at client) are obtained/assigned through "connect" and both are assigned the same src_port. The respond to this, so far, is that it is possible but probably not using the BSD socket API. Regards, Verdi -- Sparen beginnt mit GMX DSL: http://www.gmx.net/de/go/dsl