Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!tut.cis.ohio-state.edu!ucbvax!VAX.FTP.COM!jbvb From: jbvb@VAX.FTP.COM (James Van Bokkelen) Newsgroups: comp.protocols.tcp-ip.ibmpc Subject: Re: advice on software Message-ID: <8908181715.AA22284@vax.ftp.com> Date: 18 Aug 89 17:15:03 GMT References: <8908171600.AA19853@mcvax.cwi.nl> Sender: daemon@ucbvax.BERKELEY.EDU Organization: The Internet Lines: 16 Some more information on TCP connections vs. descriptors in PC/TCP: DOS 3.x has a limit of 20 file descriptors per process. Our "local" network descriptors are mapped to DOS file descriptors (the socket library uses them to talk to the kernel), so you can't have more than 20 of them per-process (you could probably get above 16 TCP connections if you could close some of the stdio handles which occupy descriptors 0-4). The 2.0 kernel also supports "global" network descriptors, which aren't mapped to DOS file handles, but for various reasons the socket library can't use them. If you code to our native-mode interface, you can open 32 simultaneous TCP connections just fine (my test program does). James B. VanBokkelen 26 Princess St., Wakefield, MA 01880 FTP Software Inc. voice: (617) 246-0900 fax: (617) 246-0901