On Thu, Sep 10, 2020 at 7:24 PM Michael Thomas <mike@mtcc.com> wrote:
We're probably not communicating because lots of carriers are using VoLTE which SIP end to end,
it's likely SIP end-to-end on the singular platform at that carrier (LTE), but if the termination gets to 'not LTE' handsets, it's not SIP anymore. If the call exits that carrier, it's not guaranteed to remain SIP all the way either.
so that is a lot more that 1%. I know that my local telco uses SIP over fiber at the little pedestal which terminates POTS and never touches SS7 anything from what I can tell. e.164 addresses are a relic of legacy telephony signalling, even if they're still used to make the user part of a From: address.
What's the thing that matters here though? "The call originator's 'true' identifying data can be carried through the network to the recipient" and that: "decisions about termination of the call can be made reliably based on the call source originator identification information" right? Can that be done on the PSTN or the SIP-parts-of-PSTN or 'sip over the wild internet' ? yes, if you require your interconnect partners to not tell lies...