After a flow fails, RFC 5626 caps the wait before re-registering at W = min(max-time, base-time * 2^consecutive-failures), with max-time defaulting to 1800 s and base-time to 30 s if all flows failed or 90 s if at least one is still up.

Checked 2026-09-25

W = min (max-time, (base-time * (2 ^ consecutive-failures)))
Vendor
not restricted
Product
SIP
Subsystem
registration-recovery
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-backoff. WarmTransfer. https://warmtransfer.net/knowledge/claims/sip-registration-failures-outbound-backoff

BibTeX

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

Read in context