Standards vision
Phone numbers are not going away. They can have company.
The phone number remains a useful public address: universally understood, portable between providers, and backed by decades of regulation. The open question is whether portable, verified identities can become an additional address type that works across providers — and who gets to define it.
Where SIP came from
SIP was specified in the open, by people who wanted session setup to work between independent networks rather than inside a single operator’s product. That intent survived the protocol’s adoption unevenly. In practice, much of the interconnect ecosystem grew into commercial wholesale chains where the two endpoints of a session know very little about each other.
The federation starts from the same premise SIP did: independent providers should be able to reach each other directly, under rules they agree to, without an intermediary defining the terms.
What we think comes next
An identity that a customer can carry between providers, that another provider can verify, and that no single vendor controls. Something closer to how a domain name works than to how a number range is assigned.
We are not claiming this is imminent, nor that it displaces numbering. We are claiming it is worth specifying carefully, in the open, by the providers who would have to implement it — and that a working peering network is a better place to learn from than a whiteboard.
Interoperability principles
These four principles constrain what the federation will build. They are proposed, and founding members are expected to argue with them.
| Principle | Meaning |
|---|---|
| Neutrality | The network is governed for participating members, not optimized to favor one carrier. No member gets routing preference, directory advantage, or policy exception by virtue of size. |
| Interoperability | Membership should not permanently lock a provider or an identity into one vendor. What a member registers, they can withdraw; what an identity holder holds, they can move. |
| Trust | Identity and routing claims must be attributable, auditable, and enforceable. A claim that cannot be traced to a responsible member is not a claim the federation should act on. |
| Privacy | Directory publication and reachability policy require explicit member and customer controls. Being reachable through the federation is a decision, not a default. |
Open questions we would rather answer together
These are unresolved. They are the substance of the working-group conversation, not settled positions.
What is the unit of identity?
Does a portable identity belong to an end customer, an organization, or a provider-issued account? Each answer implies a different authority model and a different portability process.
Who attests, and to what?
Existing call-signing frameworks attest to the origin of a call. A portable identity needs attestation about the holder as well. Those are different claims with different lifetimes.
How does reachability get revoked?
A directory that is easy to join and hard to leave is a lock-in mechanism. Withdrawal and revocation need to be as well specified as registration.
What does the directory reveal?
An eligibility lookup can leak a great deal about a competitor’s customer base. The query model has to be designed for that from the start.