For connection-oriented transports, RFC 5626 sets the default CRLF keep-alive upper bound at 120 seconds with a lower bound of 95 seconds.

Checked 2026-09-25

The fixed upper bound or the default configurable upper bound SHOULD be 120 seconds (95 seconds for the lower bound)
Vendor
not restricted
Product
SIP
Subsystem
keep-alive
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-tcp-keepalive. WarmTransfer. https://warmtransfer.net/knowledge/claims/sip-registration-failures-outbound-tcp-keepalive

BibTeX

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

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