In addition to this, the reason is probably age. Older stuff tends to use lower port numbers. Most of the backbone of the Internet proper are all under 100, with occasional variants being over, often for use with SSL (IMAP/SSL, POP/SSL, HTTP/SSL aka HTTPS).
There's also a security feature on all *nix boxes, including OS X. Ports under 1025 may only be opened by the super-user (root), so only the machine admin can start a webserver etc. Once that space of port numbers got filled up, I suspect people started randomly grabbing numbers. For example, we use 9999 and 9998 at work because someone plucked them out of thin air one afternoon :) I suspect that a company would then goto the IANA, ask for those numbers, be told "NO", and get whatever number was nearby that sounded good. So the reason is history, and then random-evolution. Hen On Thu, 19 Aug 2004, Lee Larson wrote: > On Aug 19, 2004, at 8:04 PM, Marta Edie asked: > > > But there is one question I have: who gives the numbers to these > > ports? iTunes is 3689, Printer sharing 631 and 515, remote log-in 22 > > etc-. Why these wild numbers without any , at least to me, reason? > > There's a group called IANA (Internet Assigned Number Authority) that > does it. > > <http://www.iana.net/> > > > > | The next meeting of the Louisville Computer Society will > | be August 24. The LCS Web page is <http://www.kymac.org>. > | List posting address: <mailto:macgroup at erdos.math.louisville.edu> > | List Web page: <http://erdos.math.louisville.edu/macgroup> > | The next meeting of the Louisville Computer Society will | be August 24. The LCS Web page is <http://www.kymac.org>. | List posting address: <mailto:macgroup at erdos.math.louisville.edu> | List Web page: <http://erdos.math.louisville.edu/macgroup>
