Source note · SS7 and carrier interworking concepts
RFC 3398 maps ISUP cause values 34 (no circuit available), 38 (network out of order) and 41 (temporary failure) to the SIP response 503 Service Unavailable.
Checked 2026-09-24
- Vendor
- IETF
- Product
- SIP-ISUP gateways
- Subsystem
- ISUP-to-SIP cause mapping
- Deployment
- carrier, on-premises
- Region
- not restricted
- Release range
- current as of 2026-09-24
- Checked
- 2026-09-24
Sources
- RFC 3398: Integrated Services Digital Network (ISDN) User Part (ISUP) to Session Initiation Protocol (SIP) Mapping — IETF / RFC Editor · tier 1 standards and regulators · Section 7.2.4.1 ISDN Cause Code to Status Code Mapping, table
Cite this note
APA
WarmTransfer. (2026, September 24). SS7 and carrier interworking concepts: source note ss7-carrier-interworking-cause34-38-41-to-503. WarmTransfer. https://warmtransfer.net/knowledge/claims/ss7-carrier-interworking-cause34-38-41-to-503
BibTeX
@misc{warmtransfer-claim-ss7-carrier-interworking-cause34-38-41-to-503,
title = {SS7 and carrier interworking concepts: source note ss7-carrier-interworking-cause34-38-41-to-503},
author = {{WarmTransfer}},
year = {2026},
url = {https://warmtransfer.net/knowledge/claims/ss7-carrier-interworking-cause34-38-41-to-503},
note = {Source note ss7-carrier-interworking-cause34-38-41-to-503, checked 2026-09-24}
}