Source note · Call blocking and analytics labeling remediation
RFC 8688 defines SIP 608 (Rejected) for an intermediary, such as a call analytics engine, that blocked the call; it can carry a jCard in Call-Info giving the intermediary operator's contact for redress.
Checked 2026-09-24
This code informs the SIP User Agent Client (UAC) that an intermediary blocked the call and provides a redress mechanism
- Vendor
- IETF
- Product
- SIP
- Subsystem
- response-codes
- Deployment
- any
- Region
- not restricted
- Release range
- RFC 8688
- Checked
- 2026-09-24
Sources
- RFC 8688: A Session Initiation Protocol (SIP) Response Code for Rejected Calls — IETF / RFC Editor · tier 1 standards and regulators · Section 1 and jCard/Call-Info section
Cite this note
APA
WarmTransfer. (2026, September 24). Call blocking and analytics labeling remediation: source note call-blocking-labeling-rfc8688-608. WarmTransfer. https://warmtransfer.net/knowledge/claims/call-blocking-labeling-rfc8688-608
BibTeX
@misc{warmtransfer-claim-call-blocking-labeling-rfc8688-608,
title = {Call blocking and analytics labeling remediation: source note call-blocking-labeling-rfc8688-608},
author = {{WarmTransfer}},
year = {2026},
url = {https://warmtransfer.net/knowledge/claims/call-blocking-labeling-rfc8688-608},
note = {Source note call-blocking-labeling-rfc8688-608, checked 2026-09-24}
}