Subject: RE: [Megaco] interpretation of H.248.23 andisp package and thedwa /data signals

From: "Kevin Boyle" <[email-masked]>
Date: Wed, 27 Apr 2005 12:52:30 -0400

Your interpretation is incorrect.  The dwa signal is designed to perform
data delivery associated with ANY alerting, whether prior to or during
ringing.  This is clearly stated in the procedures section of the document.

Kevin 

-----Original Message-----
From: [email-masked] [mailto:[email-masked]] On Behalf Of
Wayne Cutler
Sent: Tuesday, April 26, 2005 5:45 AM
To: [email-masked]
Cc: [email-masked]; [email-masked]; [email-masked]
Subject: Re: [Megaco] interpretation of H.248.23 andisp package and
thedwa/data signals

>Question 1:

>The description of the display with alerting signal in H.248.23 has the
following text:

>"Sends the display information to the CPE. This signal indicates that 
>the
data must be applied during alerting ? either power ringing, or call
waiting. >Therefore, this signal implies alerting, which will be
appropriately applied to the CPE by the gateway, based upon the on
hook/off-hook status of the >line."

>The ETSI specification, EN 300 659-1, On-Hook Data Transmission, 
>defines
the following data transmission methods:
>1. prior to ringing (including TAS equal to Ringing Pulse-Alert 
>Singal), 2. during ringing (ie between the first and second ringing 
>pattern)

>Which signals defined in the andisp package should be used to support 
>the
two methods because it is not clear from the andisp package descrition for
dwa >signal can be applied for method 1?

>Question 2:

>Additionally it would be useful to find out what MG and MGC vendors 
>have
implemented for methods 1 and 2.

Hi Jan,

For question 1, we'd read h248.23 as meaning that andisp/dwa should be used
for option 2 (during ringing) and andisp/data for option 1 (prior to
ringing).

In terms of question 2, this is what the Marconi CA & MSAN has implemented.

Regards,
Wayne

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---

From: "Kevin Boyle" <[email-masked]>
Date: Thu, 28 Apr 2005 09:48:14 -0400

Funny that no one asked on the list for any clarification, and instead made
a logically inconsistent assumption based upon some wording that
conveniently fit some arbitrary preconception of how it should work.  This
would seem to be a problem for the implementors, not a problem in the
standard.  I can tell you as the author of the original text proposal that
the intent is as I have described.  If it wasn't this way, then why would we
even bother with the dwa signal at all?  The premise that some of the
alerting-associated display would use dwa and some wouldn't is logically
unsound.  What benefit would that have to anyone?
 
This is the same concept that applies to the tones packages: the MG must
know how to produce the signals per its local requirements.  In the VoIP
world, it is entirely conceivable that a MG serving a handful of
terminations in one part of the world could be controlled by an MGC in a
completely different part of the world.  It is not feasible to force the MGC
to have knowledge of the physical characteristics of, for example,
congestion tone in every locality across the face of the earth.  The data
requirements alone would be staggering, considering the size and complexity
of a number of the tonesets in existence.  However, it is feasible to have
the MG aware of the single toneset it serves per its location.  The MG has
to have this information anyway, either provisioned internally or explicitly
signaled to it.  Because the MG has to know this, the logical choice is to
move the knowledge of that information to the MG, and give the MGC tools to
signal intent to the MG for the MG to translate into frequencies and
cadences.
 
Caller ID falls into the same category.  You, yourself, point out below that
there are two methods in the UK alone for delivering FSK data.  Why would we
burden the MGC with needing to know information that it will never use?  The
MG, again, must know how to setup and deliver the data.  So the logical
choice is to push that knowledge into the MG, and give the MGC a simple
signal that says "Ring the phone, and while you're at it, here's FSK to
transmit in whatever fashion is applicable for the termination."
 
More comments inline. [KJBII]
 
Kevin

  _____  

From: Wayne Cutler [mailto:[email-masked]] 
Sent: Thursday, April 28, 2005 5:06 AM
To: Boyle, Kevin [NCRTP:3Z40:EXCH]
Cc: [email-masked]; [email-masked]; [email-masked];
[email-masked]
Subject: RE: [Megaco] interpretation of H.248.23 andisp package and thedwa
/data signals

Hi Kevin, 

ETSI FSK delivery is described in ETSI EN 300 659 which has a section (6.1)
called "Data Transmission Associated with Ringing" which is then further
split into 2 sub-sections, namely "Data Transmission during Ringing" (6.1.1)
and "Data Transmission Prior to Ringing" (6.1.2). 

Interestingly, the trasnmission that uses a TAS of RP is regarded as "prior
to ringing" since the timings are different to the splash of ringing that is
used 
for the "during ringing" scenario. 

[KJBII] This is irrelevant and is a detail for the MG to handle.  The dwa
signal is specifically designed to indicate either scenario, based on the
per-termination provisioning of the local requirements applicable to the MG.

Therefore, the andisp dwa & data signals align nicely with the ETSI split
and more than one company has interpreted the standard in this way and
progressed to implementation. I would  disagree with your assertion about
the procedures "clearly stating" this distinction. In fact, the cited UK
example is incorrect since there are two methods used in the UK, namely the
"BT method" which is prior to ringing (and uses a TAS or LR followed by
DT-AS) and the "Bellocore" method used by Cable Operators (that uses a TAS
of RP). 

[KJBII] It is incorrect?  The first example shows the "Bellcore" method
which is clearly a "during ringing" delivery.  The second example shows the
"BT" method which is clearly a "prior to ringing" delivery.  Both examples
use the SAME SIGNALLING, regardless of the timing of data transfer -- as is
very clearly shown. To quote from the text describing the "BT" method: "NOTE
-- This is the same as the previous example, since TAS should be provisioned
for the gateway's location." To further quote from the procedures section
(emphasis mine): "Any location-specific signalling requirements in the setup
of the DWA delivery are implied within the signal." I am not sure how much
more explicit it can be, frankly.

I think it's a bit late to try and claim that the H248.23 words "during
alerting" means "associated with alerting" - especially given the wording of
the EN. 
 
[KJBII] I believe you are splitting hairs here in an attempt to avoid fixing
your incorrect implementation.  I note that the name of the signal is
"Display with Alerting", not "Display during Alerting". I would also point
out that "alerting" is NOT the same as "ringing".  Everyone who was
associated with the design of this package understood the intent as I have
explained it, including Bruno Chatras who was one of the major contributors
to the package as it stands today.  I note that there were NO COMMENTS to
this or any other effect from Marconi during the development of the package.
At the time, I believe that Brian Rosen was the one who was working on H.248
for Marconi. I will state again: the interpretation that dwa does not apply
to certain instances of Caller ID delivery.

Regards, 
Wayne 

	"Kevin Boyle" <[email-masked]> 

27/04/2005 17:52 

        To:        Wayne Cutler <[email-masked]>,
[email-masked] 
        cc:        [email-masked], [email-masked],
[email-masked] 
        Subject:        RE: [Megaco] interpretation of H.248.23 andisp
package and thedwa        /data signals

Kevin 

-----Original Message----- 
From: [email-masked] [ <mailto:[email-masked]>
mailto:[email-masked]] On Behalf Of Wayne Cutler 
Sent: Tuesday, April 26, 2005 5:45 AM 
To: [email-masked] 
Cc: [email-masked]; [email-masked]; [email-masked] 
Subject: Re: [Megaco] interpretation of H.248.23 andisp package and
thedwa/data signals 

Hi Jan, 

Regards, 
Wayne 

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

From: "Kevin Boyle" <[email-masked]>
Date: Thu, 28 Apr 2005 10:37:49 -0400

If the text is confusing, then we can certainly update it.  I will be more
than happy to propose a Corrigendum to H.248.23 to clear this up.
 
Kevin

  _____  

From: Jan Lindquist (AL/EAB) [mailto:[email-masked]] 
Sent: Thursday, April 28, 2005 3:03 AM
To: Boyle, Kevin [NCRTP:3Z40:EXCH]; Wayne Cutler
Cc: [email-masked]; [email-masked]; [email-masked]
Subject: RE: [Megaco] interpretation of H.248.23 andisp package and
thedwa/data signals

Hello Kevin,
 
Can the description in the dwa signal be updated?  The text is misleading
specially when comparing to the ETSI specification, during alerting and
during ringing almost have the same meaning.  Can "during alerting" be
changed to "associated to alerting"?  This will help clarify the usage of
dwa.
 
Thanks,
JanL
 
-----Original Message-----
From: Kevin Boyle [mailto:[email-masked]] 
Sent: den 27 april 2005 18:53
To: Wayne Cutler; Jan Lindquist (AL/EAB)
Cc: [email-masked]; [email-masked]; [email-masked]
Subject: RE: [Megaco] interpretation of H.248.23 andisp package and
thedwa/data signals

Kevin 

-----Original Message----- 
From: [email-masked] [mailto:[email-masked]
<mailto:[email-masked]> ] On Behalf Of Wayne Cutler 
Sent: Tuesday, April 26, 2005 5:45 AM 
To: [email-masked] 
Cc: [email-masked]; [email-masked]; [email-masked] 
Subject: Re: [Megaco] interpretation of H.248.23 andisp package and
thedwa/data signals 

Hi Jan, 

Regards, 
Wayne

---

From: "Kevin Boyle" <[email-masked]>
Date: Thu, 28 Apr 2005 11:24:11 -0400

I am sure it will help to ensure that a Corrigendum is produced in a timely
manner, and event if it didn't, it certainly wouldn't hurt matters.
 
Kevin

  _____  

Sent: Thursday, April 28, 2005 11:02 AM

Thank you Kevin.  The change is appreciated.  Do you need any liaison
statement from TISPAN to motivate the change in SG16?
Regards,
JanL
 
-----Original Message-----
From: Kevin Boyle [mailto:[email-masked]] 
Sent: den 28 april 2005 16:38
To: Jan Lindquist (AL/EAB); Wayne Cutler
Cc: [email-masked]; [email-masked]; [email-masked]
Subject: RE: [Megaco] interpretation of H.248.23 andisp package and
thedwa/data signals

Kevin

  _____  

Hello Kevin,

Thanks,
JanL
 
-----Original Message-----
From: Kevin Boyle [mailto:[email-masked]] 
Sent: den 27 april 2005 18:53
To: Wayne Cutler; Jan Lindquist (AL/EAB)
Cc: [email-masked]; [email-masked]; [email-masked]
Subject: RE: [Megaco] interpretation of H.248.23 andisp package and
thedwa/data signals

Kevin 

-----Original Message----- 

Hi Jan, 

Regards, 
Wayne