RFC 6314 notes that NAT policy can close connections after a period of inactivity. It points to RFC 5626 (SIP Outbound) keep-alives, rather than SIP signaling itself, as the way to keep NAT bindings open.

Checked 2026-09-25

NAT policy can dictate that connections should be closed after a period of inactivity.
Vendor
IETF
Product
SIP
Subsystem
NAT traversal
Deployment
any
Region
not restricted
Release range
RFC 6314
Checked
2026-09-25

Sources

Cite this note

APA

WarmTransfer. (2026, September 25). Calls that drop after about 30 seconds: source note sip-calls-drop-30-seconds-nat-binding-timeout. WarmTransfer. https://warmtransfer.net/knowledge/claims/sip-calls-drop-30-seconds-nat-binding-timeout

BibTeX

@misc{warmtransfer-claim-sip-calls-drop-30-seconds-nat-binding-timeout,
  title  = {Calls that drop after about 30 seconds: source note sip-calls-drop-30-seconds-nat-binding-timeout},
  author = {{WarmTransfer}},
  year   = {2026},
  url    = {https://warmtransfer.net/knowledge/claims/sip-calls-drop-30-seconds-nat-binding-timeout},
  note   = {Source note sip-calls-drop-30-seconds-nat-binding-timeout, checked 2026-09-25}
}

Read in context