RFC 3578 states that in overlap operation all INVITEs except one typically receive 4xx responses such as 484 Address Incomplete.
Checked 2026-10-02
- Vendor
- not restricted
- Product
- not restricted
- Subsystem
- Overlap signalling
- Deployment
- any
- Region
- not restricted
- Release range
- RFC 3578 as published
- Checked
- 2026-10-02
Sources
- RFC 3578: Mapping of Integrated Services Digital Network (ISDN) User Part (ISUP) Overlap Signalling to the Session Initiation Protocol (SIP) — RFC Editor / IETF · tier 1 standards and regulators · Section 3.3
Cite this note
APA
WarmTransfer. (2026, October 2). Troubleshooting SIP 404 Not Found and 484 Address Incomplete call failures: source note sip-404-484-troubleshooting-rfc3578-484-responses. WarmTransfer. https://warmtransfer.net/knowledge/claims/sip-404-484-troubleshooting-rfc3578-484-responses
BibTeX
@misc{warmtransfer-claim-sip-404-484-troubleshooting-rfc3578-484-responses,
title = {Troubleshooting SIP 404 Not Found and 484 Address Incomplete call failures: source note sip-404-484-troubleshooting-rfc3578-484-responses},
author = {{WarmTransfer}},
year = {2026},
url = {https://warmtransfer.net/knowledge/claims/sip-404-484-troubleshooting-rfc3578-484-responses},
note = {Source note sip-404-484-troubleshooting-rfc3578-484-responses, checked 2026-10-02}
}