Re: [codec] #5: Mention DTMF in requirements

[stephen botzko <[e-mail]>]

I would agree with this if I saw reasonable evidence that a preponderance of
gateways and sending systems provide the signaling in these RFCs.

Since I am not sure that this is the case, I am unconvinced that we can
totally remove the requirement.

I'd also say that an encoder that detects the DTMF tones and outputs the RFC
4733/34 events would fully meet the requirement.

Stephen Botzko

On Sun, Mar 28, 2010 at 11:36 AM, Marc Petit-Huguenin <[e-mail]>wrote:

> I disagree with the "SHOULD".  RFC 4733 and RFC 4734 takes care of DTMF and
> much
> more, so this must be an explicit non-goal.  This is an *Internet* codec
> that we
> are talking about so it should reuse as much as possible of the existing
> Internet framework.
>
> And BTW, RFC 473[34] is not out of band, it's codec switching.  RFC 47[34]
> is an
> audio codec, simply very good at compressing a very specific set of
> frequencies/phases, and replacing everything else by silence.  RFC 4730 and
> RFC
> 2676 are out of band.
>
> On 03/26/2010 03:37 PM, Michael Knappe wrote:
> >  I would agree with 'should'. Lot's of dtmf out there still, but also
> > out of band options (rfc 2833 / 4733) that make in-band carriage less a
> > concern for SIP telephony applications.
> >
> > Mik
> >
> > *From*: [e-mail] <[e-mail]>
> > *To*: Christian Hoene <[e-mail]>
> > *Cc*: [e-mail] <[e-mail]>
> > *Sent*: Fri Mar 26 18:10:31 2010
> > *Subject*: Re: [codec] #5: Mention DTMF in requirements
> >
> > Perhaps analog DTMF carriage is a SHOULD?
> >
> > I agree that out-of-band is preferable, however, there still are
> > scenarios where coded DTMF tones will be sent.  It would be nice (though
> > IMHO not essential) for this carriage to work.
> >
> > Stephen Botzko
> >
> > On Fri, Mar 26, 2010 at 3:04 PM, Christian Hoene <[e-mail]
> > <mailto:[e-mail]>> wrote:
> >
> >     Hi,
> >
> >     > If the point of this issue to allow this codec to be used to
> >     successfully
> >     > transit an IP network between two TDM networks,
> >
> >     which is not the primary use-case.
> >
> >     > I'd suggest that out-of-
> >     > band tone transport is far preferable to trying to ensure that the
> >     codec
> >     > will carry the tones adequately to allow them to be detected after
> >     > regeneration.
> >
> >     I totally agree. Out-of-band is much better than inband.
> >
> >     Sorry for my radical view but I believe that analog DTMF is an old
> >     and obsolete technology not worth considering anymore.
> >
> >     Christian
>
>
> --
> Marc Petit-Huguenin
> Personal email: [e-mail]
> Professional email: [e-mail]
> Blog: http://blog.marc.petit-huguenin.org
>