Back when P-Asserted-Identity was coming into being I screamed at the
top of my lungs that it was going to get abused. The reply was that the
telephone network was a closed system so it wasn't a problem. It turns
out that we were both sort of right. At that time, email submission
authentication was still pretty uncommon so most ISP's were open relay
sewers so there was nobody to name and shame, so we figured that it
would be a good idea to provide that means. That's pretty much the case
of telephony now since their providers don't care what the identity is
in the signaling. But it was always the case that they could care and
not allow spoofing, just like I can't spoof email addresses from my
gmail account. And very unlike email, telephony has lots of regulatory
machinery to require that to happen.
Mike
On 10/4/22 11:22 AM, [email protected] wrote:
On October 3, 2022 at 16:05 [email protected] (Michael Thomas) wrote:
> The problem has always been solvable at the ingress provider. The
> problem was that there was zero to negative incentive to do that. You
> don't need an elaborate PKI to tell the ingress provider which prefixes
> customers are allow to assert. It's pretty analogous to when submission
> authentication was pretty nonexistent with email... there was no
> incentive to not be an open relay sewer. Unlike email spam, SIP
> signaling is pretty easy to determine whether it's spam. All it needed
> was somebody to force regulation which unlike email there was always
> jurisdiction with the FCC.
Analogies to email are always fraught.
How often do LEGITIMATE telco customers make hundreds if not thousands
of calls per hour w/o some explicit arrangement with their telco?
As they say, a telephone company is a vast, detailed billing system
with an added voice feature.
Quite unlike email where it's mostly fire and forget plus or minus
hitting a spam filter precisely because there is no billing, no
incentive. And no voice "snowshoeing".
I doubt robocalls are ever made with anything like spam
roboarmies.
With email it's like every single computer on the net with an IP
address has, in effect, a (potentially) fully functional "originating
switch" (again, some exceptions like port 25 blocking.) People have
run spambots from others' printers etc.
