Subject: RE: Mission focus (was Re: [Sipping] Requirements fortheidentificationof IMScommunicationservices.)

From: "Mark Searle" <[email-masked]>
Date: Mon, 27 Mar 2006 09:03:12 +0100

Hi Henry,

It is clear that the only sensible route for the future is to use the
Internet to support integrated services and replace the PSTN with an
equivalent service.  The benefits are too great to avoid trying to
achieve this and the market is hungry for a solution.  21Cn in the UK is
trying to achieve this by integrating legacy PSTN edge equipment with
SIP-based (IMS) core communications.  They, of course, have the
challenge of delivering equivalence first time.  Extremely ambitious
don't you think? Especially considering organizations such as these are
more used to hard state machines, hard accountability and ASN.1 than
soft state and XML. 

By the way, I appreciate the view that flood aircraft strikes and tube
bombs are indeed major problems for telecoms.  During the tube strike
the mobile network went down because everyone tried to phone home. So
you are right that classic PSTN does not help us in these situations.
Fortunately we have Tetra and satellite phones. However, the more
pressing emergency requirement is more mundane.  A heart attack at home
or a small fire that kills the supply to one or two homes is far more
common than suicide bombers. People need to rely on service.  

I don't mean to sound negative, especially in response to Dean's email.
I am committed as anyone to delivering integration through SIP and IP as
anyone.  I just think that there is a lot learn about 100 years of
telecommunications.  Whether we achieve integration by staying faithful
to the aims of the IEFT or introduce structures that are more resonant
of the legacy PSTN I don't know. This answer to this question is as much
commercial as technical. What I do know is that telecom's has a lot to
learn about the IETF but that the dismissive attitude of some sectors of
the IETF to the PSTN is disappointing. 
 
Regards Mark

-----Original Message-----
From: Henry Sinnreich [mailto:[email-masked]] 
Sent: 27 March 2006 03:50
To: 'Mark Searle'; 'Dean Willis'
Cc: 'Andrew Allen'; [email-masked]; [email-masked]
Subject: RE: Mission focus (was Re: [Sipping] Requirements
fortheidentificationof IMScommunicationservices.)

Mark,

You are raising an interesting point:

>Perhaps SIP should ...inform ...that 
>SIP was never intended to support resilient communications.

Here are some facts: During all major recent disasters, the Internet did
not
fail while the telecom networks did fail. This has to do with the
original
Internet design to withstand atomic warfare, design from the cold war
years.

- During Katrina the mayor of New Orleans could reach the president only
using Vonage,
- During 7/11 in NY, only Internet communications worked, including an
emergency SIP service from Columbia University,
- During the floods in Central Europe, etc.

It is therefore high time to migrate the public emergency services and
emergency preemption services to the Internet. They will work more
reliable,
at less cost and allow better communications, such as video and the
conveyance of location, vital signs, etc. And last but not least the
integration with emergency applications using SIP events and presence. 

Thanks, Henry

-----Original Message-----
From: Mark Searle [mailto:[email-masked]] 
Sent: Sunday, March 26, 2006 6:02 PM
To: 'Dean Willis'
Cc: [email-masked]; 'Andrew Allen'; [email-masked];
[email-masked]
Subject: RE: Mission focus (was Re: [Sipping] Requirements
fortheidentificationof IMScommunicationservices.)

Hi,

There is a misunderstanding. I do not mean for you to replicate the act
of circuit switching at 64kbit per second.  That is easy.  You could do
it with wet string. My comment about skype was to do with running
communication services that are essential to the social and economic
well being of the country; that can be relied on in an emergency or when
the deal needs to be done.  With great responsibility comes great
dinosaur standards processes that are the curse of the PSTN as well as
one of its strengths.  Perhaps you believe that communication over the
internet should not aim for such lofty ideals.  Perhaps SIP should
therefore consider its position and inform the IMS standards body,
rather than politely consider its requirements, that SIP was never
intended to support resilient communications and the IMS is wasting its
time.  If you really believe this you might save them a lot of
unnecessary work.

Oh, and digital photography would never have taken over from 35mm if it
could not match the quality of 35mm and offer other benefits besides.
Can you say you have the correct metaphor yet?   

Regards Mark

-----Original Message-----
From: Dean Willis [mailto:[email-masked]] 
Sent: 27 March 2006 00:13
To: Mark Searle
Cc: [email-masked]; 'Andrew Allen'; [email-masked];
[email-masked]
Subject: Mission focus (was Re: [Sipping] Requirements
fortheidentificationof IMScommunicationservices.)

Mark Searle wrote:

> What ever the undoubted advantages of the Internet for delivery of
data
> services we have yet to see a functioning Internet voice service.  By
> this I mean a commercial end-user replacement for the PSTN. 

So?

The Internet is NOT the PSTN. It is a different environment, with 
different principles, different physics, different goals, different 
business models, different applications, different regulation, and a 
different user experience.

Trying to exactly replicate the PSTN on top of the Internet is at best 
an academic exercise (and as Henning might say, I mean "academic in the 
worst way").

This is equivalent to using transgenetic science to turn a turkey-on-rye

sandwich into a roast-beef-on-wheat:

http://www.sluggy.com/daily.php?date=060320

I've spent about ten years in this exercise and I've come to realize 
that while I believe using the Internet to provide applications that 
help people communicate is a very reasonable thing to do, there's no 
good reason to artificially constrain ourselves to trying to replace the

PSTN, and that worrying about "Gee, we haven't replaced the PSTN yet" is

a complete waste of time.

I expect that the PSTN will muddle along doing what it does, reliable, 
stable, and relatively stagnant, until it has become as relevant to the 
working world as the smoke signals of the neolithic plains dwellers are 
to today's average mobile-equipped high-school student. From time to 
time, there will be some transitional overlap requiring us to adapt, but

that's not really the intent, focus, and mission of this working group.

To repphrase: The mission of the SIP working group is NOT to replicate 
and/or replace the PSTN. Our mission is to define an Internet protocol 
that facilitates human-centric real-time communications.

Given that OTHER organizations (generally outside of IETF) are trying to

use our work to talk to (3GPP IMS), replicate (ETSI TISPAN ISDN 
supplementary services) or replace (ITU NGN) the PSTN or parts thereof, 
we SHOULD consider their requirements and MAY act upon them, but we MUST

NOT jeopardize our mission in doing so.

This is the Internet. Behaving "like the PSTN" is just as much of a 
requirement to our work as "advancing 35mm film between two spools" is 
to digital photography. Get the picture?

--
Dean Willis

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