On 7/9/21 3:32 PM, K. Scott Helms wrote:
On Fri, Jul 9, 2021 at 4:47 PM Michael Thomas <m...@mtcc.com
<mailto:m...@mtcc.com>> wrote:
On 7/9/21 1:36 PM, K. Scott Helms wrote:
> Nothing will change immediately. Having said that, I do expect
that
> we will see much more effective enforcement. The investigations
will
> come from the ITG (Industry Traceback Group) with enforcement
> coming from FCC or FTC depending on the actual offense. The
problem
> has been that it's been far too easy for robocalling companies
to hop
> from one telecom provider to another. Now there are requirements
> around "know your customer" that telecom operators have to
follow and
> the ITG will have a much better chance of figuring out who the bad
> actor is than they have in the past.
The thing is that that shouldn't have been held up by rolling out
STIR.
With email, there was nothing akin to the FCC so it was really the
only
name-and-shame stick we had. This could have been done years ago.
It wouldn't work the same and I say that as someone who ran email for
ISPs for decades and just got done with a STIR/SHAKEN implementation.
There's far more money in robocalls than there ever has been in spam.
The other thing is that the technologies are fundamentally different.
Don't get me wrong, there are parallels, but comparing email to the
various flavors of telephony (POTS, SIP, MGCP, H.323, etc) isn't all
that useful because they're so different. When I get an email as a
provider I can always figure out the path it took to get to me. The
same is not at all true for a call, though I can trace it to a degree
via the CDRs from carriers I work with. Much of the call path will be
opaque and often in the case of robocallers it's intentionally so.
Number porting is another (big) difference. We could always choose to
forward email for a customer who left our service, but imagine if
email literally let that person take their address with them
regardless of who was providing the hosting for the email.
Once it hits a SIP gateway it's pretty much the same. The thing that I
think that made the made the biggest -- and this coming from one of the
inventors of DKIM -- was shutting down open relays. With email there was
no back pressure on ESP's to close them so DKIM was at least a way to
name and shame, or at least that was one of the goals at least in my
mind. It's hard to say whether there was actually cause and effect, but
the reality now is that open relays are pretty much gone -- at least
with ESP's.
I was one of the early Cassandras telling people that
P-Asserted-Identity was going to lead to exactly what has happened for
which I got told I was wrong, and then threw up my hands and went and
worked on email. This could have been dealt with 15 years ago and it
could have trivially piggybacked off of the DKIM work -- heck I even
hacked a SIP stack to prove the point. And it should have learned the
lessons with email which it apparently has not because the 9th of July
don't seem any different than the 30th of June.
Also: since there are PSTN gateways which fundamentally can't be secured
spammers will take advantage of the holes as they become economically
viable. The entire scheme of attesting for e.164 addresses was a
complete waste of time. The problem is with the SIP gateway that onramps
the bogus calls not whether somebody should be able to assert a given
address real time. Those onramps could have taken those measures a
decade ago but didn't just like the open email sewers before requiring
submission auth. I think that Peterson has some other wacky shit to make
PSTN gateway traversal better, turning a Rube Goldberg contraption into
something even worse. The entire thing is madness with its complexity
but I would expect nothing less from the SIP WG.
> Longer term I worry that this will lead to more attacks on PBXs,
> eSBCs, and VOIP handsets to be able to call either from that
endpoint
> itself or be able to use the SIP credentials. The market for
robocalls
> will certainly not disappear.
>
A meta question that really needs to be asked these days is why we
even
need telco telephony anymore. A lot of problems go away if you are
not
in thrall to 100 year old technology and its accreted kruft.
Robocalls really aren't a product of the legacy PSTN. Today almost
none of them originate from anywhere but VOIP. Now, you can certainly
say that if SS7 had robust authentication mechanisms that we could
then trust caller ID (more) but there's no sign of us abandoning the
PSTN anytime soon. Having said that, there's any number of protocols
we rely on today that have the exact same gap. BGP is arguably even
worse than SS7.
I'm not speaking about PSTN qua PSTN/SS7, etc. I'm speaking about being
shackled to an architecture that isn't relevant today. The
bellheadedness of STIR is frightening: they actually scrape SIP From:
addresses and have a regex to determine if it's a telephone number.
People don't use telephone numbers for anything but phones, and all of
the rest is email addresses. There is fundamentally nothing stopping SIP
From: m...@mtcc.com be how reach me. STIR leaves that use case in limbo:
I've never been able to get a straight answer about it, which means in
reality it's not supported. I'd actually like that quite a bit more
especially since it would make it difficult right off the bat to spoof
my domain vs. spoofing area codes. Doubly so for spear phishing. We
already know how to do federation: email. There is just no justification
for keeping the legacy PSTN kruft, and even worse wagging the dog.
Mike, Cassandra to the end
