Source note · SIP registration failures
The first digit of a SIP Status-Code gives the response class (for example 4xx is a request failure), and the last two digits carry no categorisation role.
Checked 2026-09-25
The first digit of the Status-Code defines the class of response.
- Vendor
- not restricted
- Product
- SIP
- Subsystem
- message-format
- Deployment
- any
- Region
- not restricted
- Release range
- RFC 3261
- Checked
- 2026-09-25
Sources
- RFC 3261 — SIP: Session Initiation Protocol — IETF / RFC Editor · tier 1 standards and regulators · Section 7.2 Responses
Cite this note
APA
WarmTransfer. (2026, September 25). SIP registration failures: source note sip-registration-failures-status-class-digit. WarmTransfer. https://warmtransfer.net/knowledge/claims/sip-registration-failures-status-class-digit
BibTeX
@misc{warmtransfer-claim-sip-registration-failures-status-class-digit,
title = {SIP registration failures: source note sip-registration-failures-status-class-digit},
author = {{WarmTransfer}},
year = {2026},
url = {https://warmtransfer.net/knowledge/claims/sip-registration-failures-status-class-digit},
note = {Source note sip-registration-failures-status-class-digit, checked 2026-09-25}
}