Subject: [Megaco] Modify to do Audit hook state

From: "Pascal Lambers" <[email-masked]>
Date: Tue, 17 Aug 2004 22:31:52 +0200

Hello,

Megaco does not provide an Audit message to audit a termination's hook status directly. That's clear.

Instead, to know whether a termination is Off Hook, the MGC must send a Modify with an Off Hook (strict/failWrong) Events descriptor.  Consequently, if the termination is already off hook, the MG will reply with an error. Is it sure that in such a case the events and signals implemented on this termination before the Modify arrived, are still present? In other words, is it sure that messages from the MGC to the MG replied to with an error do not have any negative effect?

Kind regards,
Pascal

_______________________________________________
Megaco mailing list
[email-masked]
https://www1.ietf.org/mailman/listinfo/megaco

---

From: "Kevin Boyle" <[email-masked]>
Date: Tue, 17 Aug 2004 19:08:53 -0400

I fail to see the need for this.  The MGC must account for the current call
processing state at all times.  It is, after all, the CONTROLLER.  
 
It seems to me that the MGC has to know what the current status of the
Events descriptor is.  If it doesn't know, it can audit the Events
descriptor.  Any action the MGC takes is up to the MGC, whether the answer
is expected or not.
 
It seems to me that terminations that have a hook-state should have either
onhook detection or offhook detection in the Events descriptor at all times,
unless the term is undergoing some kind of test or is OOS.  Otherwise, how
will state transitions be detected?
 
By using the 'state' value for the parm, the MG will return the state
desired if a) a transition occurs or b) the term is already in that state.
This allows the MGC to quickly resync itself with the MG.  If the MG does
not report the event upon receipt of the events descriptor, then the MGC can
assume the hookswitch is in the opposite state and is already looking for
the correct transition.  If the event is reported, the MGC can update the
Events descriptor to change the hookstate detector while still leaving the
other events intact.
 
One final comment:  What MGCP does or doesn't do is largely irrelevant.
H.248 provides the ability for the MGC and MG to get resynced, and that is
what matters.
 
Kevin

  _____  

From: Pascal Lambers [mailto:[email-masked]] 
Sent: Tuesday, August 17, 2004 6:04 PM
To: [email-masked]
Subject: Re: [Megaco] Modify to do Audit hook state

In this case a separate Audit Hook status mechanism makes sense. It makes
sure there is no influence on call related funcionality. And as long as the
MGC receives the expected answer it must not take any corrective action. If
I'm not mistaken, MGCP allows a separate Audit.

Pascal

----- Original Message ----- 
From: Kevin Boyle <mailto:[email-masked]>  
To: Pascal Lambers <mailto:[email-masked]>  ; [email-masked]
<mailto:[email-masked]>  
Sent: Tuesday, August 17, 2004 11:49 PM
Subject: RE: [Megaco] Modify to do Audit hook state

The MGC would have to include any events previously present in the Events
descriptor in order to guarantee their continued detection, yes.

Kevin 

-----Original Message----- 
From: Pascal Lambers [mailto:[email-masked]
<mailto:[email-masked]> ] 
Sent: Tuesday, August 17, 2004 5:03 PM 
To: [email-masked] <mailto:[email-masked]>  
Subject: Re: [Megaco] Modify to do Audit hook state 

Kevin, 

"The MGC must account for these kinds of issues when it is building
messages". 
By this you mean, that if the MG returns an error "termination allready
off/on hook", the MGC has no longer any guarantee as to which events are
still programmed on the termination?

If so, the strict/exact and strict/state won't be of any help I'm afraid: 
the Modify will always overwrite events that were present on the termination
before... and if the MGC just sent this Modify to know whether the hook
status of a termination is still as it expected, without taking anything
else, this is a problem. Do I interpret this correctly?

Pascal 

----- Original Message ----- 
From: "Kevin Boyle" <[email-masked]> 
To: "Pascal Lambers" <[email-masked]>; <[email-masked]> 
Sent: Tuesday, August 17, 2004 10:45 PM 
Subject: RE: [Megaco] Modify to do Audit hook state 

> The MGC must account for these kinds of issues when it is building 
messages. 
> 
> I would note that there are two other possible values for the strict parm 
> that may be of more use: 'state' and 'exact'.  If having the MG generate 
> errors is a problem, then you could use one of the other two options 
> instead. 
> 
> Kevin 
> 
> 
> 
>   _____ 
> 
> From: Pascal Lambers [mailto:[email-masked]
<mailto:[email-masked]> ] 
> Sent: Tuesday, August 17, 2004 4:32 PM 
> To: [email-masked] 
> Subject: [Megaco] Modify to do Audit hook state 
> 
> 
> Hello, 
> 
> Instead, to know whether a termination is Off Hook, the MGC must send a 
> Modify with an Off Hook (strict/failWrong) Events descriptor. 
Consequently, 
> if the termination is already off hook, the MG will reply with an error. 
Is 
> it sure that in such a case the events and signals implemented on this 
> termination before the Modify arrived, are still present? In other words, 
is 
> it sure that messages from the MGC to the MG replied to with an error do 
not 
> have any negative effect? 
> 
> Kind regards, 
> Pascal 
> 
> 
> 
> 
<https://www1.ietf.org/mailman/listinfo/megaco>  

_______________________________________________ 
Megaco mailing list 
[email-masked] 
https://www1.ietf.org/mailman/listinfo/megaco
<https://www1.ietf.org/mailman/listinfo/megaco>