Subject: Note to Henry (Was: Re: DTMF signaling between media gateways - ouch!)

From: "Pete Cordell" <[email-masked]>
Date: Tue, 23 Nov 1999 17:25:17 -0000

Sorry for busting ya party Henry.  I didn't realise a personal invitation
was required.

Trouble is, I don't see any point inventing fan-dabby-doozo new services if
the basics are not covered off.  I reckon that 80% of calls even in the
brave new world of SIP will never go any where near any fancy services.
Degrading the basic call experience in these cases so that we can add a few
extra services does not make sense to me.  From a US perspective I can see
this issue is not a big problem, but globally I think you would be
committing suicide if this is not catered for.  Sure, if we could say this
can be handled by the gateways that would be great, but my analysis (and I'm
quite happy for others to prove me wrong) shows that it can't be.
Unfortunately, that means that SIP has to tackle it.

Sorry for not proving to be entertaining, but in reality Jonathan's last
e-mail seems to be pretty much there in terms of crystallising what needs to
be said.  Let's finish it off.  I too will then be pleased to see this
thread end!

Pete

=============================================
Pete Cordell
[email-masked]
=============================================

-----Original Message-----
From: Henry Sinnreich <[email-masked]>
To: Pete Cordell <[email-masked]>; Schroeder, Tim
<[email-masked]>; [email-masked]
<[email-masked]>
Date: 23 November 1999 13:28
Subject: RE: DTMF signaling between media gateways - ouch!

>Pete Cordell wrote
>> I'm here because
>
>Pete, if this is the reason for stuffing our mail, just say so and let's
get
>back to designing features we need for new services. As mentioned,
telephony
>legacy systems can be accommodated by gateway features and their ways need
>not be ported to the Internet. I suggest we stop this thread, it's been a
>drag already.
>
>Henry
>
>Henry Sinnreich
>MCI WorldCom
>400 International Parkway
>Richardson, Texas 75081, USA
>
>
>> -----Original Message-----
>> From: [email-masked]
>> [mailto:[email-masked]]On Behalf Of Pete Cordell
>> Sent: Tuesday, November 23, 1999 5:24 AM
>> To: Schroeder, Tim; [email-masked]
>> Subject: Re: DTMF signaling between media gateways - ouch!
>>
>>
>> My feeling is that SIP stopped being purely an initiation protocol a long
>> time ago.  In fact, when the BYE method was added, it no longer was
purely
>> an initiation protocol.  It went further down the path when all the call
>> transfer stuff was added.
>>
>> I'm here because SIP is being touted as a solution for Internet
Telephony,
>> which involves more, much more, than just initiation.  If that's not what
>> it's about a decision needs to be made quickly and the message
>> that is being
>> spread by SIP advocates needs to be changed to avoid confusion in
>> the market
>> place.
>>
>> Pete
>>
>> =============================================
>> Pete Cordell
>> [email-masked]
>> =============================================
>>
>> -----Original Message-----
>> From: Schroeder, Tim <[email-masked]>
>> To: [email-masked] <[email-masked]>
>> Date: 22 November 1999 23:44
>> Subject: RE: DTMF signaling between media gateways - ouch!
>>
>>
>> >I'm a bit confused by much of this DTMF discussion.  SIP is a Session
>> >Initiation Protocol, so it understands how to initiate sessions.  As for
>> the
>> >mid-call DTMF tones,
>> >
>> >(1) If they are coming from some network where those tones *do* have
>> session
>> >initiation implications, then the gateway ought to be able to map them
to
>> >the existing set of SIP messages in some rational fashion.  So, in a
>> network
>> >where the DTMF 7 tone (R for record) means to add a recording
>> device to the
>> >call, the SIP gateway would map this to an invite of a recording
>> device to
>> >the call.
>> >
>> >(2) If those tones don't have session initiation implications,
>> then I don't
>> >see why any of the SIP network servers would understand them
>> (any more than
>> >a gateway would understand them); only the end systems would.  Yes, they
>> may
>> >be used for signaling, but it's not session initiation signaling, and I
>> >don't understand the desire to somehow wrap them up into SIP messages
and
>> >send them between end systems that way.  I see SIP as being used
>> to set up
>> a
>> >session between end systems, possibly consisting of two media
>> channels, one
>> >used for end system signaling, one used for end system data.  I haven't
>> made
>> >the leap that because the end systems are interpreting some data as
>> >signaling, that the data should be sent using SIP messages.
>> >
>> >My impression from reading all the DTMF messages (and in trying
>> to catch up
>> >-- there were a lot of them!) is that two separate kinds of signaling
>> >(session initiation, and some higher level service signaling) are being
>> >confused.  Currently SIP handles the first type.  Adding the INFO method
>> >might make it able to handle some of the second type, but I
>> don't think it
>> >can handle all service signaling that easily.
>> >
>> >Tim Schroeder
>> >
>> >
>> >
>> >This e-mail and any files transmitted with it are the property of SBC,
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>> >named recipient(s) or otherwise have reason to believe that you have
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>> >or copying of this e-mail is strictly prohibited.
>> >
>> >
>> >
>>
>>
>
>
>

---

From: "Gregory D. Girard" <[email-masked]>
Date: Tue, 23 Nov 1999 21:20:23 -0500

Michael,
Please see my comments below marked "GG:"

-

>Greg,
>
>I guess that since the Internet has functionality above the PSTN
>that it would have been Dead-on-Arrival too?

GG: The internet as currently deployed has yet to offer itself as a
telephony market to compete with the PSTN for  point-to-point connections.
And even service provider's today are not suggesting anything but very
carefully manged IP links, only very few of which have anything to do with
the internet. The difference is that SIP is positioned as an IP-version of
the PSTN singnaling mechanisms; the "data equivelent" if you will. In that
capacity, if it cannot
allow an application to perform on a parity with PSTN interfaces, it has not
use to telephony interfaces used in my company's products. Another solution
will have to be found while we all marvel at SIP advanced features.

>
>Seems odd to me that you are commenting on an IETF list.

GG: IETF has invade the telephony space via the data-oriented telephony
solutions supported by media gateways interconnected via IP backbone.
Insofar as internet technologies are involved, it falls under the IETF. No
big mystery there.

>
>Lets get real here .... your customers would have NEVER given
>you feedback on ICQ (e.g., AOL IM or Yahoo Messenger) a
>few years ago. Why ... because they didn't know what these
>new features could do for them.

GG: My customers are sophisticated next gen service providers, many of who
monitor this to watch the progress, and who will comment on activity you see
here. For example, I got a call from one thanking me for stirring the SIP
pot regarding the much neglected DTMF issue that have raised such a stir.
This very comment may read by a customer or potential customer, most of whom
realize that services can't get rolled out over a pure data interface till
this SIP interface is worked out.
>
>The Internet provides lots of services that can be used in concert
>with real-time transport (e.g., telephony apps) ... probably the most
>user impacting apps have not yet been written! ... but we desire an
>architecture that enables them.

GG: Excellent, then why would that we ignore base-line functionality that is
already a defacto and de jure standard in the telephony world ? Lets build
on a base of functions rather than spin off into advance features. I'll
grant you that JPEG images through signaling pathways and web integration
with signaling interfaces is exciting futuristic stuff. My only point is
that without basic features, we can't roll-out the services for the existing
market.
>
>If you really feel this way .... that we are brain-dead for not replicating
>EVERY functionality of the PSTN in the IDENTICAL manner the PSTN
>implements them .... I have to wonder what you are doing here?
>
>(He tried to say in as nice a way as possible),

GG: I understand your frustration with party poopers like myself and others
that keep pressing for boring old PSTN-like features. We are really nice
guys...well, actually I don't know them personally, but anyways...I've got a
problem and maybe you can help me:

I have 10+ service providers that say they would just love to drop our
platform in to provide a whole range of rather basic telephony services,
ranging from calling card, to voice mail, to unified messaging. Only thing
is, they are building a VoIP or VoATM infrastructure and insist on a
data-only services interface to keep pace with the data-centric network
architecture. If I go along to get along, I don't have a story for them that
they believe, or for that matter, that I believe.  There are a lot of loose
ends and I've brought them to the attention of this list. My inquiries here
have generated HUNDREDS of messages in the last few weeks, about half of
which elaborate on the subject in a very serious manner. Obviously someone
has felt that basic service issues like DTMF were important enough to
discuss.  After considering the many many thoughtful opinions presented
here, I believe that I finally do have a solution to my problem set, so for
me the excercise was very rewarding. Whether or not the SIP model moves
forward as a result is another matter. I offer no apologies for making the
point that SIP functionality *may* need to address a larger problem set than
anticipated years ago when first incepted.

Greg Girard
>
>Michael Ramalho
>
>
>At 06:23 PM 11/23/99 -0500, Gregory D. Girard wrote:
>>Hey Pete, you hit the nail on the head in your comments below. I've done
the
>>analysis. I've spoken to the customers. We (Iperia) have relationships
with
>>all major gateway manufacturers. The message is crystal clear that SIP (Or
>>its replacement/adjunct) must cover the basics before any fancy stuff even
>>matters a damn to anyone anywhere. If SIP can't duplicate legacy for
>>starters, it Dead on Arrival and will belong in the archives of great
>>intellectual achievements that never made it commerically, right up there
>>with the H.324 videophone stuff where the bottom fell out about a year
ago.
>>Greg Girard
>>From: Pete Cordell <[email-masked]>
>>To: Henry Sinnreich <[email-masked]>
>>Cc: [email-masked] <[email-masked]>
>>Date: Tuesday, November 23, 1999 12:30 PM
>>Subject: Note to Henry (Was: Re: DTMF signaling between media gateways -
>>ouch!)
>>
>>
>Michael A. Ramalho, Ph.D.
>Cisco Systems
>Wall Township, NJ
>Office email: [email-masked]
>Personal email: [email-masked]
>Office: +1.732.449.5762
>Cell: +1.732.809.0188
>