Subject: RE: [Sipping] Kill Overlap Dialling

From: "Mark Watson" <[email-masked]>
Date: Wed, 27 Aug 2003 17:12:31 +0100

Pleeeeeease don't start this again ...

I don't think the reasons for overlap dialling, which we discussed for a
looooooong time, very painfully, have changed significantly.

As for end-of-dialling keys on SIP phones, I'd be surprised if anyone on
this list had not seen sipphone.com. You can try selling this kind of thing
in Europe without overlap, but expect reviewers to complain about connection
times. They will not always realise that most of it is the inter-digit
timer.

You can certainly change user behaviour if you explain to them that it works
differently from an old-style phone & if there is something in it for the
user as well. But if it 'looks and feels' just like a phone there will
always be people who expect it to work just like a phone. Service providers
& the market, not IETF, should decide how important those people are.

...Mark

-----Original Message-----
From: Christian Stredicke [mailto:[email-masked]] 
Sent: 26 August 2003 06:37
To: 'sipping'
Subject: [Sipping] Kill Overlap Dialling

Hi All,

the feedback which I received so far on overlap dialling was pretty
clear: There will be no overlap dialling support for SIP.

Arguments:

A. ENUM does not support overlap dialling. There are security concerns on
who will own the nodes of incomplete numbers and it was also reported that
the overhead for the node lookup is too much.

B. Countries with fixed-length numbers (like USA) can have a dial plan on
the phone. Other countries always need to press the dial button except for
cases where extension numbers are dialled. People calling from the US have
to press a dial key (or #) after dialling a non-US number. That is accepted
by the customers.

C. The lack of support of 484 responses on PSTN gateways makes overlap
dialling unusable anyway. A SIP extension would be necessary, but does not
exist at this time and the probability that we reach consensus on such an
extension in time is minimal. 

D. "Grandma" is not in the customer focus any more. "Grandchildren" are used
to cell phones and press the dial button after making up their minds on
which person to call.

E. Phones without display will not be sold in large numbers any more. If
vendors should decide to make SIP phones without display, they must include
a dial button (timeout of 5 seconds to start dialling is not feasible as
this makes printed telephone book lookup impossible).

Am I right? I this is so, we would like to stop efforts on implementing this
in out endpoints.

Best,

Christian

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---

From: Henry Sinnreich <[email-masked]>
Date: Thu, 28 Aug 2003 08:24:39 -0500

>You can try selling this kind of thing in Europe 
>without overlap, but expect reviewers to complain about connection times.

Are they buying mobile phones nevertheless?

Henry

________________________________________
From: [email-masked] [mailto:[email-masked]] On Behalf Of
Mark Watson
Sent: Wednesday, August 27, 2003 11:13 AM
To: 'Christian Stredicke'; 'sipping'
Subject: RE: [Sipping] Kill Overlap Dialling

-----Original Message----- 
From: Christian Stredicke [mailto:[email-masked]] 
Sent: 26 August 2003 06:37 
To: 'sipping' 
Subject: [Sipping] Kill Overlap Dialling 

Hi All, 

Christian 

_______________________________________________
Sipping mailing list  https://www1.ietf.org/mailman/listinfo/sipping
This list is for NEW development of the application of SIP
Use [email-masked] for questions on current sip
Use [email-masked] for new developments of core SIP

---

From: "Christian Stredicke" <[email-masked]>
Date: Fri, 29 Aug 2003 10:05:29 +0200

Sorry I was a few days offline...

The mobility feature allowed the call phones to have horrible features
like dropping packets, bad voice quality, high prices, etc...

Additionally, if you try overlap dialling on a cell phone you would be
surprised on the "look and feel": while you are still looking at the
handset (entering the number), the other party might be already
connected. That’s why all intelligent users put the handset as quick as
possible to the ear waiting for some tone!

That is different with a "classical" phone: When you dial, you have the
handset already on the ear. Hands free mode mimics that behaviour. 

Chance that we get overlap dialling into ENUM: zero. Chance that we get
all PSTN gateways to support it: almost zero. 

It's (maybe) sad but true: overlapped dialling is dead for SIP.

Christian

> -----Ursprüngliche Nachricht-----
> Von: Henry Sinnreich [mailto:[email-masked]]
> Gesendet: Donnerstag, 28. August 2003 15:25
> An: 'Mark Watson'; 'Christian Stredicke'; 'sipping'
> Betreff: RE: [Sipping] Kill Overlap Dialling
> 
> D. "Grandma" is not in the customer focus any more. "Grandchildren"
are
> used
> Am I right? I this is so, we would like to stop efforts on
implementing
> this