In the RFC 3665 registration example the credentialed retry REGISTER keeps the same Call-ID as the challenged REGISTER and increments CSeq from 1 to 2.

Checked 2026-09-25

Vendor
not restricted
Product
SIP
Subsystem
registration
Deployment
any
Region
not restricted
Release range
RFC 3665
Checked
2026-09-25

Sources

Cite this note

APA

WarmTransfer. (2026, September 25). SIP registration failures: source note sip-registration-failures-callid-cseq-retry. WarmTransfer. https://warmtransfer.net/knowledge/claims/sip-registration-failures-callid-cseq-retry

BibTeX

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

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