Trace caller-ID disagreements hop by hop

When a handset displays a different caller ID than an upstream provider record, do not assume application identity selection failed and do not add identity headers speculatively. Correlate the same call across the application transfer, originating SIP INVITE, provider ingress and egress, terminating carrier, and handset detail.

At each boundary, separate asserted identity headers from forwarding provenance, privacy, and attestation. Apply one minimal correction at the first boundary where identity changes and preserve required forwarding headers until trace evidence shows they are wrong.

A provider record may summarize ingress or normalized fields and does not prove the egress INVITE or handset presentation. Adding an asserted-identity header cannot reliably repair a downstream override.