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From: gardner@shl.com (Gardner Buchanan)
Newsgroups: comp.protocols.iso
Subject: ROSE Invoke-IDs
Message-ID: <1991Mar20.195234.27916@shl.com>
Date: 20 Mar 91 19:52:34 GMT
Organization: SHL Systemhouse Inc.
Lines: 40


CCITT X.219/X.229 Geniuses, I have a dumb question about using ROSE:

I appologise in advance if it seems that I don't understand this enough
to even ask a meaningful question but here goes...

I find myself working with a presentation protocol which contains
mostly Class 3, 4 and 5 operations.  It looks like I will have a bit
of trouble keeping track of all of the un-responded Invoke-IDs which
will proliferate, particularly with the Class 3 operations.

I'm not worried about deciding when I can re-use Invoke-ID values,
since it is quite easy to never (within reason) reuse them at all, but
I still might have to keep a table of invokes I've generated for a fair
piece of history just on the off chance that an ERROR might be
returned by the responder.

So, does anyone know where in the CCITT/ISO docs it might say just how
much history I might have to remember?  X.219 Sec. 10.1.1.4 says that I
may re-use Invoke-IDs after "a reasonably long period of time".  This
would, I guess, also apply to the length of time I must remember about
the invokation.  Does that seem right?

Before asking the remaining questions, I will state that I DID NOT
DESIGN THE APPLICATION OR ITS OPERATIONS!!!!

Is it in general a good idea to use Class 3 and 4 operations if they
lead to this difficulty in deciding when the operation is over?  Do
many other applications use them?

Are there well known algorithms for maintaining a table of Invoke-IDs
like the one I think I need?  Is there something in the ISODE which
I should look at?


Thanks for any and all assistance,
-- 
Gardner Buchanan           gardner@shl.com
Systemhouse, Ottawa
(613) 236-6604 x375