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Secure Caller-ID Fallback Mode

The information below is for an old version of the document.
Document Type
This is an older version of an Internet-Draft whose latest revision state is "Replaced".
Expired & archived
Author Eric Rescorla
Last updated 2014-01-15 (Latest revision 2013-07-14)
Replaced by draft-ietf-stir-oob, draft-ietf-stir-oob, RFC 8816
RFC stream (None)
Stream Stream state (No stream defined)
Consensus boilerplate Unknown
RFC Editor Note (None)
IESG IESG state Expired
Telechat date (None)
Responsible AD (None)
Send notices to (None)

This Internet-Draft is no longer active. A copy of the expired Internet-Draft is available in these formats:


A major challenge with RFC 4474-style identity assertions has been that SIP operates in highly mediated and interworked environments. SIP requests may pass through gateways, policy enforcement devices or other entities that receive SIP requests and effectively act as user agents, re-initiating a request. In these circumstances, intermediaries may recreate the fields protected by the RFC4474 signature, making end-to end integrity impossible. This document describes a mechanism for two compliant endpoints to exchange authentication data even in the face of intermediaries which remove all additional call signaling meta-data or which translate from SIP into protocols incapable of understanding identity meta-data (e.g., where one side is the PSTN).


Eric Rescorla

(Note: The e-mail addresses provided for the authors of this Internet-Draft may no longer be valid.)