RFC 5626 requires registrars that implement it to support the Path header mechanism, and the outbound option tag tells the UA the registrar is compliant.

Checked 2026-09-25

Registrars that implement this specification MUST support the Path header mechanism
Vendor
not restricted
Product
SIP
Subsystem
registration
Deployment
any
Region
not restricted
Release range
RFC 5626
Checked
2026-09-25

Sources

Cite this note

APA

WarmTransfer. (2026, September 25). SIP registration failures: source note sip-registration-failures-outbound-path-required. WarmTransfer. https://warmtransfer.net/knowledge/claims/sip-registration-failures-outbound-path-required

BibTeX

@misc{warmtransfer-claim-sip-registration-failures-outbound-path-required,
  title  = {SIP registration failures: source note sip-registration-failures-outbound-path-required},
  author = {{WarmTransfer}},
  year   = {2026},
  url    = {https://warmtransfer.net/knowledge/claims/sip-registration-failures-outbound-path-required},
  note   = {Source note sip-registration-failures-outbound-path-required, checked 2026-09-25}
}

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