[Css-csts] Comments about the Association Control state table

[Martin Götzelmann]

Dear John,

The specifications you are addressing have obviously been copied from the SLE Books. 

Is it really the case that a service instance does not exist before the service instance provision period starts? As service instances are agreed in advance by service management, "something" must exist before that time. Maybe what exists is only the agreement that there will be a service instance but I feel conceptually one could consider a service instance to be created by service management and to exist as soon as it is scheduled. Also in a real implementation a service instance will have to be created before the start of the provision period in order to be ready to receive a BIND invocation when the provision period starts. In fact the BIND diagnostics include the code 'invalid time' specified as "the BIND operation was invoked outside the service instance provision period of the service instance identified by the service-instance-identifier parameter" (also copied from the SLE books).

Where we do have a problem is with the association control procedure if we insist that this procedure is created only when the service instance has been bound ... If we keep the specification that procedures are instantiated only after binding we will have to say that the association control procedure is different and we will have to add corresponding words to section 2 and maybe to association control procedure specification as well.

Concerning the events in detail:

[Ad 1] The event 'start of service instance provision period' is only needed for provider initiated binding. In fact is included in the RAF book but not in the CLTU book. As provider imitated binding is no longer supported, I think we should remove this event.

[Ad 2] Due to the arguments stated earlier, I would not have a problem with "[ignore]", but maybe "-> terminate" is clearer provided we find a precise definition of what "terminate" means. I guess "terminate" would apply also when the provider is in the bound state (following the PEER-ABORT). We would also have to consider how to express termination of the service instance when the user unbinds with the reason set to 'end'. Obviously one would first have to complete the bind operation and then terminate ... There might be more cases to consider and I wonder whether the added clarity is worth the added complexity of the state table.

Best Regards,
Martin

-----Original Message-----
From: css-csts-bounces at mailman.ccsds.org [mailto:css-csts-bounces at mailman.ccsds.org] On Behalf Of John Pietras
Sent: 26 March 2008 20:39
To: css-csts at mailman.ccsds.org
Subject: [Css-csts] Comments about the Association Control state table

I have two comments about the effects of the service instance provision
period on the Association Control procedure state table. 

First, in the v0.12 Procedures Definition version of the state table,
for the Incoming Event 'start of service instance provision period', the
action is listed as [ignore] when the provider is in the 'unbound'
state. It is my understanding that the service instance and its
Association Control procedure instance do not exist until the start of
the service instance procedure period, so that the procedure and service
cannot even *be* in the unbound state in order to ignore the event. I'm
not sure how this could be represented in the state table. Perhaps the
"[ignore}" can be changed to "Not applicable", accompanied by a note
along the lines of "The 'start of service instance provision period'
initiates the service instance and Association Control procedure and
places them in the 'bound' state".

Second, for the Incoming Event 'end of service instance provision
period', the action is again listed as [ignore] when the provider is in
the 'unbound' state. It's my understanding that when the service
instance provision period ends the service instance and the Association
Control procedure terminate. I believe that "[ignore]" should be
replaced by "-> terminate".

Please provide comments on my comments. Is my understanding correct, and
if so do my suggestions make sense?

Best regards,
John

John Pietras
Global Science & Technology, Inc. (GST)
7855 Walker Drive
Suite 200
Greenbelt, Maryland, USA
20770-3239
Direct:   +1-240-542-1155
GST Main: +1-301-474-9696
Fax:      +1-301-474-5970


_______________________________________________
Css-csts mailing list
Css-csts at mailman.ccsds.org
http://mailman.ccsds.org/cgi-bin/mailman/listinfo/css-csts

______________________________________________________________________
This email has been scanned by the MessageLabs Email Security System.
For more information please visit http://www.messagelabs.com/email 
______________________________________________________________________