[Css-csts] protocol question

[Tim Ray]

Hi Martin,

I agree with you.  (That was my opinion before asking the question, but I
didn't want to influence the answer)

In my opinion, these words summarize the situation:

"After invoking the CLTU-UNBIND operation, the initiator must not invoke
any further operations (with the exception of a Peer-Abort)."

Thanks for resolving this issue (unless someone has a dissenting opinion).

Best Regards,
Tim Ray





-----Original Message-----
From: Martin Goetzelmann [mailto:Martin.Goetzelmann at vega.de] 
Sent: Tuesday, December 06, 2005 2:30 PM
To: 'Tim Ray'
Cc: css-csts at mailman.ccsds.org
Subject: RE: [Css-csts] protocol question

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Hi Ray,
I cannot give you an definitive answer but this is how I understand the
SLE Books.
>From the specification of the PEER-ABORT operation is seems to be quite
clear to me that this operation can be invoked at any time by any party
after a BIND invocation und up to the point where UNBIND return is
issued (provider) or received (user) or a protocol abort occurs.
My understanding of the intention of note 3 in section 4.1.3 is that the
user should no try start or request any activity (e.g. invoke START,
request a status report, or get a parameter) once he has initiated
unbinding. In addition, the note points out that the return for an
operation that was invoked before the UNBIND might not be received by
the user because the provider is not obliged to send that return once
the UNBIND invocation arrived. In such cases, the user should not invoke
PEER-ABORT because of the missing return.
I do not believe this refers to the case where the UNBIND return is not
sent in good time. If the UNBIND return is missing the association must
be terminated somehow and the means foreseen for such error cases is
PEER-ABORT.
I believe that my view is supported by clauses 3.3.1.3 including Note
and 3.3.1.4 (CLTU Book e.g.)
To be very precise, the note might have been better phrased something
like the following:
"After invoking the CLTU-UNBIND operation, the initiator must not invoke
any further operations with the exception of the case addressed in
3.3.1.4, nor send any returns...."
K
ind Regards,
M
artin Götzelmann
VEGA Informations-Technologien GmbH
Robert-Bosch-Straße 7
D-64293 Darmstadt
Germany
Tel : +49 6151 8257-147
Fax : +49 6151 8257-171
Email : Martin.Goetzelmann at vega.de
Web : www.vega-group.de
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From:
css-csts-bounces at mailman.ccsds.org
[mailto:css-csts-bounces at mailman.ccsds.org]
On Behalf Of
Tim Ray
Sent:
05 December 2005 20:13
To:
css-csts at mailman.ccsds.org
Subject:
[Css-csts] protocol question
Hello all,
I can’t complete the User side Operation Layer state tables (due
12/15/05) until someone answers the question below
The basic SLE protocol (as presented in chapter 4 of the existing SLE
data transfer Blue Books) does not seem to clearly define the User’s
response to certain events that may occur while an Unbind-Invocation is
pending (I’ve capitalized certain words to make the problem clearer):
Section 4.1.1 says to INVOKE THE PEER-ABORT OPERATION in response to an
Unexpected SLE Protocol Data Unit.
Section 4.1.2 says to INVOKE THE PEER-ABORT OPERATION in response to
things like an incoming return that is not decodable.
Section 4.1.3 says to INVOKE THE PEER-ABORT OPERATION in response to a
missing return.
Yet, note 3 within section 4.1.3 says that “After invoking the UNBIND
operation, the initiator MUST NOT INVOKE ANY FURTHER OPERATIONS nor send
any returns”.
May the User invoke a Peer-Abort operation while an Unbind-Invocation is
pending?
Best regards,
Tim Ray
NASA/Goddard
mailto:Tim.ray at nasa.gov Tim.ray at nasa.gov