Taken together, the sources show From as a user-supplied, displayable identity and PAI as the network-asserted identity, which is why platforms can show an anonymous or main-number From while carrying the real caller in PAI for billing or attestation.
inferred · Checked 2026-10-02
- Vendor
- not restricted
- Product
- not restricted
- Subsystem
- P-Asserted-Identity
- Deployment
- multi-tenant, on-premises
- Region
- not restricted
- Release range
- current as of 2026-10-02
- Status
- inferred
- Checked
- 2026-10-02
Sources
- RFC 3325: Private Extensions to the Session Initiation Protocol (SIP) for Asserted Identity within Trusted Networks — IETF / RFC Editor · tier 1 standards and regulators · Sections 1 and 9.1, read with RFC 3261 8.1.1.3 and Microsoft ForwardPai Example 2
Cite this note
APA
WarmTransfer. (2026, October 2). SIP identity headers: P-Asserted-Identity and Diversion and History-Info: source note sip-identity-headers-pai-vs-from-roles. WarmTransfer. https://warmtransfer.net/knowledge/claims/sip-identity-headers-pai-vs-from-roles
BibTeX
@misc{warmtransfer-claim-sip-identity-headers-pai-vs-from-roles,
title = {SIP identity headers: P-Asserted-Identity and Diversion and History-Info: source note sip-identity-headers-pai-vs-from-roles},
author = {{WarmTransfer}},
year = {2026},
url = {https://warmtransfer.net/knowledge/claims/sip-identity-headers-pai-vs-from-roles},
note = {Source note sip-identity-headers-pai-vs-from-roles, checked 2026-10-02}
}