The question about extension of an H.248 package.

Christian Groves christian.groves at ERICSSON.COM
Sun Jun 19 22:21:08 EDT 2005


Hello Sasha,

Please see my response below.

Regards, Christian

Sasha Ruditsky wrote:

> Hi Christian
> 
> Thanks, again.
> 
> It looks like I will have some more question about H.248.19.
> 
> Meanwhile.
> 
> In H.248.19 defines vwp/wxp and vwp/wyp as being from 0 to 10000. 
> 
> The description text states:
> This property is set by the MC to represent the horizontal "X" position
> of the bottom left hand corner of a window. 
> 0 represents the left hand side of a screen, 
> 10000 the right hand side of a screen. 
> 
> So it makes the size of the screen equal to 10001 units.
> 
> In the same time vwp/wh and vwp/wl are also defined to be 0 to 10000.
> 
> I think it means that it is impossible to create window which fills the
> entire screen.
> (Screen is 10001 units and the biggest window is only 10000).

[CHG] Given a display 10000 by 10000 pixels the way I saw the property
working 
was that 0,0 represented the bottom left hand corner of the
display/window. A 
window position 0,0 size 1,1 would draw a pixel 1,1 starting at this
point. A 
window placed at 10000,10000 couldn't actually have a positive size as it
would 
exceed the display.

> 
> Do I misunderstand the description text?
> Shouldn't the vwp/wxp and vwp/wyp be defined in range from 0 to 9999?
> Or probably the range is OK, however the 10000 is outside of screen?

[CHG] So technically 10000 is outside the meaningful range for displaying
anything.

> 
> What do you think?
> ====================================================================
> 
> Another small editorial issue is that in H.248.19 on Figure 8 the text
> references the vwpcvsp/ovs, where I believe it should be cvsp/ovs. 

[CHG] Is the editorial issue in Figure 8 itself? It should be cvsp/ovs but
I 
can't see where the error occurs.

> 
> 
> 
> Thanks,
> Sasha
> 
> 
> 
> 
> -----Original Message-----
> From: Christian Groves [mailto:christian.groves at ericsson.com] 
> Sent: Thursday, June 16, 2005 8:55 PM
> To: Sasha Ruditsky
> Cc: itu-sg16 at external.cisco.com
> Subject: Re: The question about extension of an H.248 package.
> 
> Hello Sasha,
> 
> In thus case the text encoding would use H.248.15 Gateway control
> protocol: SDP
> H.248 package attribute.
> 
> Regards, Christian
> 
> Sasha Ruditsky wrote:
> 
> 
>>Hi Christian
>>
>>Thanks.
>>
>>One more question.
>>In H.248.19 most of the properties inside packages are specified to be
> 
> 
>>"Defined in: Local/Remote".
>>>From what I know about H.248 -- local/remote descriptors contain SDP
>>messages.
>>
>>How do the H.248.19 properties coexist with SDP?
>>Is it only possible in binary encoding mode?
>>
>>Thanks,
>>Sasha
>>
>>-----Original Message-----
>>From: Christian Groves [mailto:christian.groves at ERICSSON.COM]
>>Sent: Thursday, June 16, 2005 12:35 AM
>>To: Sasha Ruditsky
>>Cc: itu-sg16 at external.cisco.com
>>Subject: Re: The question about extension of an H.248 package.
>>
>>Hello Sasha,
>>
>>There is no hard rule of what to propose. It really depends on the 
>>type of information you want added.
>>
>>I think the only time the package extension should be used is if the 
>>added properties/signals/events provide a set of functions of their 
>>own right. e.g.
>>would it makes sense that these properties could be a package by 
>>themselves but need another package to operate. For example: The tone 
>>gen package. The DTMF was added as a extension package as DTMF 
>>generation is its own subset functionality but is related to the 
>>generation of tones.
>>
>>Regards, Christian
>>
>>Sasha Ruditsky wrote:
>>
>>
>>
>>>Hi
>>>
>>>I'm working on a proposal for July meeting to add some new properties 
>>>to one of  the H.248.19 packages.
>>>>From H.248 document it appears that there are defined (at least) two
>>>ways of doing this.
>>>
>>>*	Creating a new version of an existing package
>>>*	Creating a new package that extends the existing one.
>>>
>>>
>>>Can somebody please comment on the factors helping to determine which 
>>>of these two mechanisms should be uses?
>>>
>>>Thanks,
>>>Sasha
>>>.
>>>
>>
>>
> 
> 
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