Subject: [Rucus] Lost use cases

From: "Pars Mutaf" <[email-masked]>
Date: Thu, 27 Mar 2008 01:41:45 +0200

Hello,

What is missing IMHO is a discussion about the profits
of publishing phone numbers. If we can understand why
users would like to publish their phone numbers on the Web
(and why they can't today) we can better measure the
problem.

Cell phone users do not publish their phone numbers
today because they want to avoid undesired calls.

For example, I would very much like to leave a message
on a forum for selling an item or asking for help and paste my
cell phone number. We can invent many possible use cases of
cell phones. Today we do not publish our phone numbers because
we don't even think about it. We unconsciously fear SPIT and
protect our tranquility.

What (i.e. which use cases of cell phones) we really lose
because of SPIT or "the fear of it"? This question has not been
answered IMO.

Regards,
pars
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From: "Dan Wing" <[email-masked]>
Date: Wed, 26 Mar 2008 18:02:39 -0700

> -----Original Message-----
> From: [email-masked] [mailto:[email-masked]] 
> On Behalf Of Pars Mutaf
> Sent: Wednesday, March 26, 2008 4:42 PM
> To: [email-masked]
> Subject: [Rucus] Lost use cases
> 
> Hello,
> 

My cellular phone and my home phone are not running VoIP, so I
don't fear SPIT.  Rather, I fear some whack-job person, awake
at 2am in the morning (in my timezone), who wants to get 
information about the item I am selling.  

I would say it is the inability for me, as the owner of the
phone number, to set policies for who can call me and when
they can call me.  Some mobile phones have such a capability
with custom ringtones (including no ringing for unknown
numbers), which can also be adjusted based on time.  With that,
and with the ability to prevent redirecting to voicemail, I 
could reasonably publish my number on a public forum -- 
afterall, it isn't just EBAY and Craigslist where I might want
to have random people call me.

This does not seem to be a new problem with VoIP, SIP, or 
SPIT -- or am I missing something?

-d

---

From: "Pars Mutaf" <[email-masked]>
Date: Thu, 27 Mar 2008 13:05:26 +0200

On Thu, Mar 27, 2008 at 3:02 AM, Dan Wing <[email-masked]> wrote:
>  don't fear SPIT.

Excuse the bad sentence. I mean, you probably fear SPIT hence
here you are in this ML interested in the problem.

>  Rather, I fear some whack-job person, awake

Why are you preventing redirecting to voicemail. You are
unconsciously limiting yourself. These are not solutions.
A better solution would be to use a disposable phone number.

>  SPIT -- or am I missing something?

Why are we looking for a new problem? There is already a problem.
Users have shown already that they can't want to publish their
phone numbers without SPIT.

The problem is not even telemarketing calls. The problem is
the possibility to receive undesired calls to that device that you
carry in your pocket. The number that you paste on the web,
stays on the web. But the solution is not hiding the numbers.
This cannot be called a solution.

Thanks,

pars

- Hide quoted text -

---

From: "Pars Mutaf" <[email-masked]>
Date: Thu, 27 Mar 2008 13:15:53 +0200

To check if there is already a problem (without SIP) you can Google the
term "Disposable phone number" , for example.

With this regard, SIP even brings a solution to unwanted calls. Because it can
make the design and distribution of disposable phone numbers easier
and cheaper. You don't need multiple phone lines with SIP. You don't
need to "buy" them.

Regards,
pars

---

From: "Dan Wing" <[email-masked]>
Date: Thu, 27 Mar 2008 08:27:40 -0700

> To check if there is already a problem (without SIP) you can 
> Google the term "Disposable phone number" , for example.

I may have poorly worded my previous email.  I agree there
is a problem today with receiving phone calls.  Today's problem, 
however, is not "SPIT".

The only viable approach to the problem of "which phone number
should I place in my classified advertisement to sell my car", on 
the PSTN, is a disposable phone number.

> and cheaper. You don't need multiple phone lines with SIP. You don't

Yes, we can probably have have disposable URIs, and phone numbers, 
cheaper in SIP than we could in the PSTN.

-d

---

From: Dan York <[email-masked]>
Date: Thu, 27 Mar 2008 14:25:53 -0400

Pars,

> (and why they can't today) we can better measure the

I don't understand this point.  I *do* publish my phone number on my  
web pages today. Thankfully I don't receive many calls.

> today because they want to avoid undesired calls.

Perhaps, but I *do* see quite a few postings on the web, especially  
in forums selling things, that do include valid phone numbers. Maybe  
this is just true in North America, but I see phone numbers all the  
time online.

> cell phones.

I do that today.  I've posted numerous items to Craigslist.org that  
have included my actual phone number.

> Today we do not publish our phone numbers because

Maybe I need more caffeine today but I guess I still don't understand  
the point you are trying to make.

Are you saying that you believe people do NOT post their cell phone  
online because they do not want to receive "unwanted  
communications"?  And that you believe we need to categorize *why*  
people do not post their phone numbers?

If so, I'm not entirely clear what this precisely has to do with  
SPIT.  I can think of many reasons not to post my phone number that  
have everything to do with regular communication over the PSTN and  
have nothing whatsoever to do with SIP.

To put that another way, what is different about posting your number  
on the web if SIP is a transport versus PSTN?  Why is this special  
and something we should think about?

Confused,
Dan

-- 
Dan York, CISSP, Director of Emerging Communication Technology
Office of the CTO    Voxeo Corporation     [email-masked]
Phone: +1-407-455-5859  Skype: danyork  http://www.voxeo.com
Blogs: http://blogs.voxeo.com  http://www.disruptivetelephony.com

Build voice applications based on open standards.
Find out how at http://www.voxeo.com/free

---

From: "Pars Mutaf" <[email-masked]>
Date: Thu, 27 Mar 2008 20:28:35 +0200

On Thu, Mar 27, 2008 at 5:23 PM, Dan Wing <[email-masked]> wrote:
>  > From: Pars Mutaf [mailto:[email-masked]]
>  > Sent: Thursday, March 27, 2008 12:49 AM
>  > To: Dan Wing
>  > Subject: Re: [Rucus] Lost use cases
>  >
>  Yes, that is one approach.
>
>  Or a phone number with policies attached to it.
>
>
>  I agree.
>  But a disposable phone number is a phone number that is published
>  one day and, one day later, purposefully made to not work.
>
>  Would it not be best to publish a phone number that always worked,
>  and provided exactly the policies the owner desired?

If we can design it, or depending on the designs, having a single phone
number may be easier for the user, I agree. This is in fact possible with
IPsec. Equivalent of and even better than disposable phone numbers can
be made with IPsec.

IPsec security associations are end-to-end hence disposable ;-)

BTW I have a draft on that issue:
https://www1.tools.ietf.org/html/draft-mutaf-humanresolv-00

> Policies
>  meaning who can call, when they can call, and even potentially
>  _why_ they are calling.

I agree for "who" and "when". But "why" can itself be exploited for
spam I guess. I can send you spam explaining you why I'll call you.
But IMO the solutions must be designed for flexibility. The user's
should be able to choose solutions. After all user experience will
determine which solutions work best and how they work best.

>  And allow for exceptions if the caller
>  is willing to expend effort; afterall, there are exceptions today
>  if the caller is willing to expend effort -- today, that effort
>  is usually social engineering effort.

IMO the caller can always be required some reasonable effort.
But this also must be designed for flexibility. This may not
work for lazy callers and sometimes the call may be beneficial
for the callee.

pars

---

From: "Pars Mutaf" <[email-masked]>
Date: Thu, 27 Mar 2008 21:07:35 +0200

On Thu, Mar 27, 2008 at 8:25 PM, Dan York <[email-masked]> wrote:
>  Pars,
>
> I don't understand this point.  I *do* publish my phone number on my web
> pages today. Thankfully I don't receive many calls.

> I do that today.  I've posted numerous items to Craigslist.org that have
> included my actual phone number.

...
> Perhaps, but I *do* see quite a few postings on the web, especially in
> forums selling things, that do include valid phone numbers. Maybe this is
> just true in North America, but I see phone numbers all the time online.

My first question: do you publish your "cell" phone number? Personally,
I did it and I seriously regretted.

Why? Because cell phone number is different. Believe me I did research on my
friends. I asked 10s of people. Everybody says that they wouldn't publish cell
phone number. Cell phone number is somewhat precious, cell phone user has a
different psychology probably because cell phone became an extension of the
body.

My second question: would you publish your phone number on a dating site?
(not you nor me, I mean the user perspective)

My third question: would you publish your cell phone on a phone book?
Why cellular phones do not have phone books? This means that phone
book is useless? We have a lot of phone books for home phones.

> Are you saying that you believe people do NOT post their cell phone online
> because they do not want to receive "unwanted communications"?

Yes.

> And that you
> believe we need to categorize *why* people do not post their phone numbers?

Defining use cases where users would in normal conditions publish
their phone numbers look like a good idea.

> If so, I'm not entirely clear what this precisely has to do with SPIT.  I
> can think of many reasons not to post my phone number that have everything
> to do with regular communication over the PSTN and have nothing whatsoever
> to do with SIP.
>
> To put that another way, what is different about posting your number on the
> web if SIP is a transport versus PSTN?  Why is this special and something we
> should think about?

For example, SIP URIs have "sip:" before the phone identifier and can be
more easily detected by robots. But this is orthogonal to the fact that cell
phone number is more precious. Maybe not.

pars

---

From: "Dan Wing" <[email-masked]>
Date: Thu, 27 Mar 2008 13:08:57 -0700

> My first question: do you publish your "cell" phone number? 
> Personally, I did it and I seriously regretted.
> 
> Why? Because cell phone number is different. Believe me I did 
> research on my friends. I asked 10s of people.  Everybody says 
> that they wouldn't publish cell phone number.  Cell phone 
> number is somewhat precious, cell phone user has a 
> different psychology probably because cell phone became an 
> extension of the body.

It is not just different psychology -- it is money.  In the United 
States, it costs money to receive a cellular phone call with any 
of the major carriers (AT&T, Sprint, Verizon, T-Mobile, etc.).  In 
Europe and most other GSM-centric countries, incoming calls are 
free.  

Almost everywhere in the world, incoming calls to land-line phones
are free.

-d

---

From: "Pars Mutaf" <[email-masked]>
Date: Thu, 27 Mar 2008 22:31:13 +0200

>  of the major carriers (AT&T, Sprint, Verizon, T-Mobile, etc.).  In

Thanks for the information.

>  Europe and most other GSM-centric countries, incoming calls are

Yes here incoming calls are free.
pars

---

From: "Pars Mutaf" <[email-masked]>
Date: Fri, 28 Mar 2008 14:44:41 +0200

>  of the major carriers (AT&T, Sprint, Verizon, T-Mobile, etc.).  In

What are the incentives making the callee pay in US?
Is it likely to be the same with SIP?
Depends on link-layer technology?

Thanks,
pars

---

From: John Levine <[email-masked]>
Date: 28 Mar 2008 15:26:16 -0000

>What are the incentives making the callee pay in US?

To considerably summarize and oversimplify, in North America we have
the world's largest integrated numbering area, with all phone numbers
in a fixed length 3+3+4 format where the first three digits are an
area code assigned to a particular geographic area. It now covers the
U.S., Canada, all of the remote island parts of the U.S., and many of
the islands in the Caribbean.*

When cellular phone service was invented in the early 1980s, there
weren't enough spare area codes to overlay a separate set for mobile
phones, so they integrated mobile phones into the standard numbering
and dialing plan.  They also integrated them physically; many early
cell switches attached to the network like large PBXes.

Since you could not and cannot tell from the number dialed whether
you're calling a fixed or mobile phone, the rule has always been that
the cost to the caller depends only on the rate center of the number
called.  Back in the 1980s the rates were distance sensitive, these
days for landlines they're typically free for local calls and a flat
rate elsewhere in the country, for mobiles they're all flat rated.
This means that the mobile user pays whatever extra cost his carrier
charges for mobile service.  There were a few experiments with caller
pays mobile, all of which were complete failures for both technical
reasons (no way to pass the charge through on inbound long distance
calls) and the practical reason that nobody was willing to call them.

This has a couple of advantages relative to caller pays.  One is that
since the mobile customer is aware of all of the per minute costs, we
have robust price competition for all mobile calls, and the average
per minute cost (overall, not just outbound) is about half here what
it is in Europe.  The latest round in the price wars is $99/mo flat
rate for unlimited inbound and outbound calling, a price that is
certain to drop in the next couple of years.  Another advantage is
that we have number portability between mobile and landline, with most
of the action being people porting their old landline numbers to
mobile.

People used to hide their mobile numbers for fear of getting unwanted
calls they'd have to pay for.  These days we all have bundle plans
that include more monthly minutes than we ever use, so people who hide
their phone numbers do it either out of habit, or because their phone
is always on and they don't want it to ring at inconvenient times
unless it's someone they know they want to talk to.

>Is it likely to be the same with SIP?

It's certainly going to be the same that no North American caller
would put up with extra charges to call some numbers.  The only
surcharged numbers here are in the special purpose 900 area code which
is very disreputable and is widely blocked from business phones.

We already see call management features on VoIP phones that e.g.
divert off-hours calls to voicemail except from numbers on a
whitelist.  Even without spit, this is useful to avoid the annoyance
factor of callers on the other side of the country who can't figure
out that it may be 9 AM where they are, but it's 6 AM where you are.

R's,
John

* - If anyone's wondering why we don't do it the ITU way, it's because
AT&T offered their plan to the ITU about 50 years ago and the ITU
turned it down and invented a plan that protected PTT fiefdoms.
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From: "Dan Wing" <[email-masked]>
Date: Fri, 28 Mar 2008 09:03:13 -0700

> What are the incentives making the callee pay in US?

That way, carriers get money in both directions.  It has just always
been set up this way -- since the dawn of the US's closed cellular
system.  Blame it on Craig McCaw, founder of McCaw Cellular.  The
US system was designed for in-car cellular phones with more powerful
transmitters; this saves money over handheld units which require 
more ground stations.  It took a decade for this trend to finally
reverse itself.  The carriers have little incentive to give up
their revenue for incoming minutes.

> Is it likely to be the same with SIP?

I don't know; that is a business decision.  Certainly things 
like the iPhone and gPhone (Android) could well cause the
existing revenue model to be adjusted.

> Depends on link-layer technology?

I would say it depends more on what the market will bear.

-d