Source note · SIP 503 and trunk out-of-service failures
On such a failure the client SHOULD send an otherwise identical request with a new Via branch (a new transaction) to the next element in the DNS SRV-ordered list.
Checked 2026-09-25
That request is sent to the next element in the list as specified by RFC 2782.
- Vendor
- IETF
- Product
- SIP
- Subsystem
- DNS server location
- Deployment
- any
- Region
- not restricted
- Release range
- current as of 2026-09-25
- Checked
- 2026-09-25
Sources
- RFC 3263: Session Initiation Protocol (SIP): Locating SIP Servers — RFC Editor / IETF · tier 1 standards and regulators · Section 4.3 (also Section 4.2)
Cite this note
APA
WarmTransfer. (2026, September 25). SIP 503 and trunk out-of-service failures: source note sip-503-trunk-failures-rfc3263-next-server. WarmTransfer. https://warmtransfer.net/knowledge/claims/sip-503-trunk-failures-rfc3263-next-server
BibTeX
@misc{warmtransfer-claim-sip-503-trunk-failures-rfc3263-next-server,
title = {SIP 503 and trunk out-of-service failures: source note sip-503-trunk-failures-rfc3263-next-server},
author = {{WarmTransfer}},
year = {2026},
url = {https://warmtransfer.net/knowledge/claims/sip-503-trunk-failures-rfc3263-next-server},
note = {Source note sip-503-trunk-failures-rfc3263-next-server, checked 2026-09-25}
}