Source note · Wrong or missing caller ID on outbound calls
A user agent may send P-Preferred-Identity to a trusted proxy as a hint about which identity to assert, and the proxy must remove that header from any message it forwards.
Checked 2026-09-25
The proxy MUST remove the user-provided P-Preferred-Identity header from any message it forwards.
- Vendor
- IETF
- Product
- SIP
- Subsystem
- identity headers
- Deployment
- any
- Region
- not restricted
- Release range
- RFC 3325
- Checked
- 2026-09-25
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 · Section 6 (P-Preferred-Identity / hints for multiple identities) as returned by retrieval
Cite this note
APA
WarmTransfer. (2026, September 25). Wrong or missing caller ID on outbound calls: source note caller-id-presentation-problems-ppi-removed-by-proxy. WarmTransfer. https://warmtransfer.net/knowledge/claims/caller-id-presentation-problems-ppi-removed-by-proxy
BibTeX
@misc{warmtransfer-claim-caller-id-presentation-problems-ppi-removed-by-proxy,
title = {Wrong or missing caller ID on outbound calls: source note caller-id-presentation-problems-ppi-removed-by-proxy},
author = {{WarmTransfer}},
year = {2026},
url = {https://warmtransfer.net/knowledge/claims/caller-id-presentation-problems-ppi-removed-by-proxy},
note = {Source note caller-id-presentation-problems-ppi-removed-by-proxy, checked 2026-09-25}
}