Path: utzoo!attcan!uunet!mcsun!ukc!tcdcs!csvax1.cs.tcd.ie!swift.cs.tcd.ie!omahony
From: omahony@swift.cs.tcd.ie
Newsgroups: comp.protocols.iso
Subject: question on OSI addressing
Message-ID: <4633@swift.cs.tcd.ie>
Date: 23 Nov 89 14:40:38 GMT
Organization: Computer Science Department, Trinity College Dublin
Lines: 13

I have a (fairly basic) question for implementors of OSI protocol stacks:

In order to establish an associaion with a remote application layer,
one specifies an Application Context + a PSAP address

ultimately this must expand to a SSAP, TSAP, NSAP, DSAP etc.

How does one choose, for example, what DSAP should be used on the
remote node? - in advance of any communication taking place.

X.25 has a similar situation with logical channel identifiers, but these
are purely a local matter between user and network and guidelines exist
on how they should be allocated.