That is why it is always a good idea to disallow the ephemeral port number range (1024-4999) for your own server application port otherwise you can get occasional EADDRINUSE situations.
Rob Scott Developer Rocket Software 275 Grove Street * Newton, MA 02466-2272 * USA Tel: +1.617.614.2305 Email: rsc...@rs.com Web: www.rocketsoftware.com -----Original Message----- From: IBM Mainframe Discussion List [mailto:ibm-m...@bama.ua.edu] On Behalf Of J R Sent: 04 November 2009 14:59 To: IBM-MAIN@bama.ua.edu Subject: Re: Final Confusions on Concurrent Server Multiple concurrent connections between a client and server are achieved by use of so-called "ephemeral ports" at the client end. The port number at the server end is predetermined and fixed so that a client always knows where it has to connect to. It is not necessary that the port number at the client end be known ahead of time since no one needs to connect to it. Rather, a server needs to respond to it and knows what it is from the connection request. ======= > Date: Tue, 3 Nov 2009 17:13:58 -0800 > From: hwill...@megapathdsl.net > Subject: Re: Final Conlusions on Concurrenrt Server > To: IBM-MAIN@bama.ua.edu > > "Shmuel Metz , Seymour J." wrote: > > > In <000001ca5b6c$532d3e30$f987ba...@net>, on 11/01/2009 > > at 10:26 PM, Joe Reichman <joereich...@optonline.net> said: > > > > >Here are my Final Conclusions These can only be one Active > > >Conversation > > >between a Client and Server on a port (if its between two different > > >machines) > > > > If the client is using multiple port numbers then it should be able > > to > > sustain multiple conversations with a single server. TCP/IP does not > > allow > > concurrent multiple conversations between a single src-IP:port > > dst-IP port > > pair. > > Actually, technically speaking, TCP/IP has no concept of a conversation. > TCP/IP provides a reliable point to point connection over which you > can have > as many conversations as you want. > > > > > > > -- > > Shmuel (Seymour J.) Metz, SysProg and JOAT > > ISO position; see http://patriot.net/~shmuel/resume/brief.html > > We don't care. We don't have to care, we're Congress. > > (S877: The Shut up and Eat Your spam act of 2003) > > Regards, > Henry _________________________________________________________________ Hotmail: Trusted email with powerful SPAM protection. http://clk.atdmt.com/GBL/go/177141665/direct/01/ ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to lists...@bama.ua.edu with the message: GET IBM-MAIN INFO Search the archives at http://bama.ua.edu/archives/ibm-main.html ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to lists...@bama.ua.edu with the message: GET IBM-MAIN INFO Search the archives at http://bama.ua.edu/archives/ibm-main.html