Subject: Re: Parameters in Local Control

From: "Rosen, Brian" <[email-masked]>
Date: Thu, 13 Jul 2000 17:06:40 -0400

If the ONLY thing you can put in a descriptor is
a property=value construct, then I think you don't need,
and don't want to have to, repeat values.  That would apply
to local and remote too.

All of our examples, to date, do not assume that you have
to repeat old values.

I don't think there is any concept of "deleting" properties.
What kind of properties were you thinking of?

Brian

> -----Original Message-----
> From: Christian Groves [mailto:[email-masked]]
> Sent: Wednesday, July 12, 2000 5:01 AM
> To: Rosen, Brian
> Cc: [email-masked]
> Subject: Re: Parameters in Local Control
>
>
> G'Day Brian,
>
> Why would we have a distinction in behaviour between Local Control,
> Local and Remote? They will all have property=value
> constructs and have
> properties defined by packages. We also have a concept to "delete"
> properties which needs to be maintained for Local Control.
>
> I wasn't particularly keen on having to re-send properties to
> keep them
> but that's what we decided to do so I feel that to be consistent in
> behaviour that we should keep things as is.
>
> Cheers, Christian
>
> "Rosen, Brian" wrote:
> >
> > In the text, section 7.1.7, it states:
> > A new setting of the LocalControl Descriptor completely replaces the
> >    previous setting of that descriptor in the MG.  Thus to retain
> >    information from the previous setting the MGC must include that
> >    information in the new setting.  If the MGC wishes to delete some
> >    information from the existing descriptor, it merely resends the
> >    descriptor (in a Modify command) with the unwanted information
> >    stripped out.
> >
> > Suppose you implemented a couple packages that defined a dozen or
> > so properties.  Do you have to repeat the values of each of these
> > properties in every modify of LocalControl?
> >
> > I think this paragraph is a remnant of an earlier concept, and with
> > LocalControl defined as it is now, this statement is in error, and
> > the actual desired behavior is that values are kept until modified.
> > Consider that LocalControl presently has only the Mode property,
> > the ReserveGroup and ReserveValue properties and properties of
> > a termination.
> > This means there is nothing in LocalControl that is not a property
> > with a value (as opposed to, say a flag).  Thus keeping old values
> > is very feasible, and I believe, what is desired.
> >
> > Brian
>
>

---

From: Christian Groves <[email-masked]>
Date: Fri, 14 Jul 2000 22:54:17 +1000

G'Day Brian,

I'm a little confused by this. In Megaco we settled on the following
behaviour:
"A new setting of a Local or Remote Descriptor completely replaces the
previous setting of that descriptor in the MG.  Thus to retain
information from the previous setting the MGC must include that
information in the new setting.  If the MGC wishes to delete some
information from the existing descriptor, it merely resends the
descriptor (in a Modify command) with the unwanted information stripped
out."

I believe that properties=values are applicable for local and remote. So
to date we do assume that you have to repeat old values. The issue is
that we need to be able to remove a property after we have set it to a
value otherwise in every single property we need a value to turn the
property off.

For example:
You have a stream with media flowing.
If you audited_value then no modem would appear.
You then put a modem property on a line.
If you audited_value then a modem property would appear.,
You then turn the modem property off because you want to remove it
(remove the associated physical resource from the stream).
Do an audit and it still appears. I thought that you wouldn't want to
see anything as you removed the modem.

Another example:
You have a stream with media flowing but with no reference to an echo
canceller.
You add the echo canceller property and turn it ON.
You turn the echo canceller OFF but you still want it inlinked in the
call but not operating, turning the property to off would allow this
behaviour.
You then want to outlink the echo canceller. Removing the property would
allow this.

So I believe you need to be able to:
o Assign a property a value.
o Turn this property off.
o Remove this property.
I don't think we should start playing with this behaviour now.

Cheers, Christian

PS: I'll be on holiday for a week so I probably won't get a chance to
reply in a hurry