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Re: [Ecrit] FW: [Geopriv] Winterbottom-ecrit-direct considered



Brian,

Is the security goal here more access control (i.e., controlling who can send calls to a PSAP) or attribution/identification for post-hoc action.

If it's the latter, then ISTM that the problem can largely be reduced to having a certificate infrastructure that binds authenticated identities to real-world entities. The "extended validation" certificates that current commercial CAs issue seem to largely satisfy this requirement.

--Richard


On Oct 27, 2009, at 4:31 PM, Brian Rosen wrote:

Of course not all VSPs will have trust relationships with all PSAPs. One can hope that long term, we can evolve to transitive trust relationships
that work pretty well cross border.

The emergency guys are actually terrified of private/individual domains sending them calls, and we're telling them we expect that to be possible, but rare, and we're giving them mechanisms that will effectively allow them to turn off calls selectively, based on factors including what domain the call comes from. They expect that such calls will be one of the loopholes where they get equivalents to sim-less calls, which drive them nuts. They don't want ANY calls that don't come from service providers, although they seem to be okay with the notion that the SP may not have great identity (AOL being a poster child). So, while indeed they understand, and have concerns about having to take calls from Sierra Leone VoIP services Pty, they would much rather have a call that went through them then a call that went through
no service provider at all.

I'm not trying to make calls direct from devices or private domains
impossible, but I think the notion that we're promoting them is a very bad
idea until we have effective mechanisms to prevent abuse.

Brian




On 10/27/09 9:02 AM, "Marc Linsner" <mlinsner at cisco.com> wrote:

Brian,

I'm a little confused. I don't remember you objecting to requirement RE1
from RFC5012 and I remember your use case about a Sierra Leone VSP.

Are you implying that *all* VSPs will have a trust relationships with *all*
PSAPs?

What is the difference between a call coming from a private/ individual domain (as in not a commercial VSP) and a VSP on the other side of the world
(outside the jurisdiction)?

I'm trying to figure out whether you're objecting to anonymous calls to the
PSAP or the mechanisms proposed in this draft?

[Don't take this as my endorsement of the draft, as I'm not sure I agree
with UAs registering with the ESRP.]

-Marc-


On 10/26/09 8:59 PM, "Brian Rosen" <br at brianrosen.net> wrote:

First of all, I put it on the wrong email list, sorry about that.

Then, we have carefully arranged it so that there is no identity coming from the access network provider, and because the location is coming from that provider, we really don't want to. But even if we did, we would need a
really good identifier, and there isn't one.

The problem we have with -direct is anonymous callers, and if they have any option, they would also be location-less. Until and unless we get rid of anonymity, we can't encourage service provider-less calls. The draft does not make any provision to provide any kind of identity. Many networks (think free wifi for example) would make providing good identity difficult.

The fact is that there is a SERVICE provider in nearly all of the
communications systems. The SERVICE provider is in a position to assist the emergency calling system when it needs more information. That's what a good SERVICE provider does. Cutting them out is not a great idea. Most of the attempts to provide real time communications between people have evolved
to using service providers, even when there were alternatives.  File
transfer via something like Torrent is a counterexample (which isn't real time), but even there, you end up with service providers like The Pirate Bay (R.I.P) to provide introduction services. I don't think we're going to see changes that eliminate service providers, and in this case, they provide value to the emergency calling systems. All of the emergency professionals I know have issues with service providers, but they would react with horror
if you suggested cutting them out.  Ask them, please.

So, I claim you have a solution in search of a problem. We have solved the
"calling network isn't the access network" problem already.  Service
providers ARE in the path now, in nearly every case (in fact a counter example escapes me, although there probably are some). There is no movement I can detect which would change that any time soon; quite the opposite. We have a known killer problem without some kind of subscription to a service that provides a good identity, for which you provide no answers. We have experience with the killer problem: sim-less calling was supposed to provide a way to make an emergency call in exactly the kinds of circumstances you are describing. Our real world experience is that you create a huge problem
that diverts resources from helping people to chasing scammers and
flea-market sellers.

Nothing is perfect: you can get a AIM screen name without a very good identity for example. However, the notion that we're going to provide direct access without a service provider deliberately, especially without really good identity from the access network is, in my opinion not only a no, it's a heck no. I'll line up as many emergency service professionals as
you would like to tell you this is a harmful idea.






On 10/26/09 7:56 PM, "Dawson, Martin" <Martin.Dawson at andrew.com> wrote:

I am glad this has come up. It's a debate that has to happen if we are to
move
beyond a long standing legacy misconception.

In the circuit service world - whether it was POTS or mobile, the access network had full responsibility for delivering the emergency call. In that world, routing an emergency call meant getting a circuit established to the correct call center. In most parts of the world, this was done using the regional part of the PSTN to switch the circuit to a call center on the
PSTN.
In some jurisdictions, such as the US, it was done directly from the local exchange carrier to the call center. Either way, there was no third party
involved.

Now we have the Internet. We still have public access network providers.
They
switch packets onto the Internet for their subscribers. They can similarly
ensure that packets reach the local emergency call centers.

The fact is that there was no equivalent of a VSP in the traditional environment. VoIP is a presence service, and it had no common equivalent in the PSTN world. It could have, but the narrowband state of technology and
the
common market use cases didn't support its development. By the time ISDN arrived, the PSTN had already slipped into its palliative stage without
realizing it.

It's an entrenched misconception that because the circuit service provided
by
exchange carriers was most commonly used for "voice" (but, it should be
noted,
also for fax, telex, tty, security system monitoring and, even, IP data)
that
VSPs are somehow equivalent to exchange carriers. They are not.

Indeed, involving VSPs in emergency calls is the Internet equivalent of involving long distance providers in POTS emergency calls. They are neither necessary nor particularly helpful; they can't be guaranteed to be within
the
emergency jurisdiction; depending on them actually diminishes the efficacy
of
emergency service access. It does not help the caller, the emergency
service,
nor the third party to insist on the third party's involvement.

It can't be helped if you have over sold the benefits of VSP involvement to yourself and others Brian. It is time to have a reasoned debate. From my perspective, the argument that there is no "subscription" involved is
patently
false. There has to be a subscription of some description in order to get to the Internet. Yes, there is free public Internet access (just as there are free courtesy phones on the PSTN and free access to emergency services from pay phones. All these services are still connected to the public Internet infrastructure and they all represent an "operator" with some level of
information about the caller.

With the over-emphasis on VSPs, what is missing from the ECRIT and i3 models is the direct interface for querying the access network for subscriber data (should it prove necessary). These models need to take the long view of how
emergency calling is done in the Internet age; they should not be
protracting
an unnecessary reliance on VSPs.

I have deleted the premature and prejudicial text from the subject heading.
And I'll leave this on ECRIT as the most appropriate WG.

Cheers,
Martin

-----Original Message-----
From: ecrit-bounces at ietf.org [mailto:ecrit-bounces at ietf.org] On Behalf Of
Hannes Tschofenig
Sent: Tuesday, 27 October 2009 8:23 AM
To: ecrit at ietf.org
Subject: [Ecrit] FW: [Geopriv] Winterbottom-ecrit-direct considered harmful,
at least given our current experiences

FYI: feedback from Brian regarding a recent ECRIT contribution.

-----Original Message-----
From: geopriv-bounces at ietf.org
[mailto:geopriv-bounces at ietf.org] On Behalf Of Rosen, Brian
Sent: 26 October, 2009 23:10
To: geopriv at ietf.org
Subject: [Geopriv] Winterbottom-ecrit-direct considered
harmful, at least given our current experiences

The notion behind -direct is to not use a service provider to
place an emergency call.  Instead, the device registers with
an Emergency Services Routing Proxy immediately before the
call and the call is routed directly from the device to the ESRP.

At least at the moment, this is an exceedingly bad idea.

Emergency calling authorities like service providers, a lot.
They like them because they can hold them accountable, and the
service providers don't like theft of service, which is
something the emergency call guys have an analog to.

The facts are that where unaccountable access to emergency
calling is allowed, huge numbers of false calls occur, with no
way to stop them, and no way to tell the good ones from the
bad ones.  This has been seen multiple times where so called
"simless" or "unauthenticated" calls are allowed.

-direct precisely duplicates simless calling.  The only
"registration" is an emergency registration, only emergency
calls are allowed, any device can make an emergency call if
all it has is a (radio) connection to any network.
We can predict, with a very high degree of certainty, that the
feature will be horribly abused: for example to test that a
phone without a service plan works.

There have been studies which show tens of thousands of bad
calls with zero good ones.  Nearly every authority I know
where the regulator has insisted on simless calling wants it
repealed.  There is one counter example I know where the fact
that they got a couple, literally, of good calls among the
tens of thousands of bad calls was considered enough reason to
put up with the problem.

Service providers give us information that may be useful: a
subscriber name and address for example, which is not
spoofable by the caller.  They have ways to trace callers,
especially bad callers.  They don't want their systems abused
any more than the emergency calling authorities do.

This is a bad idea.  A very bad idea.  Please stop it.

Someday, we may have better ways to prevent abuse. Until we
do, service providers are a good thing on an emergency call.
We don't want them cut out.

Brian

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