Source note · Carrier escalation evidence packages
RFC 3398 maps ISUP causes 34, 38, 41, 42 and 47 (no circuit, network out of order, temporary failure, switching equipment congestion, resource unavailable) to SIP 503 Service Unavailable.
Checked 2026-09-24
- Vendor
- IETF
- Product
- SIP-ISUP interworking
- Subsystem
- cause mapping
- Deployment
- any
- Region
- not restricted
- Release range
- RFC 3398
- 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 8.2.6.1, ISUP cause to SIP response table
Cite this note
APA
WarmTransfer. (2026, September 24). Carrier escalation evidence packages: source note carrier-escalation-evidence-isup-congestion-503. WarmTransfer. https://warmtransfer.net/knowledge/claims/carrier-escalation-evidence-isup-congestion-503
BibTeX
@misc{warmtransfer-claim-carrier-escalation-evidence-isup-congestion-503,
title = {Carrier escalation evidence packages: source note carrier-escalation-evidence-isup-congestion-503},
author = {{WarmTransfer}},
year = {2026},
url = {https://warmtransfer.net/knowledge/claims/carrier-escalation-evidence-isup-congestion-503},
note = {Source note carrier-escalation-evidence-isup-congestion-503, checked 2026-09-24}
}