RFC 6314, an Informational RFC from July 2011, assumes NATs without SIP-aware ALGs. It notes that ALGs have limits, including needing signaling and media to pass through the same device and failing with encrypted signaling.

Checked 2026-09-25

Vendor
IETF
Product
SIP
Subsystem
NAT traversal / ALG
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-rfc6314-no-alg-assumption. WarmTransfer. https://warmtransfer.net/knowledge/claims/sip-calls-drop-30-seconds-rfc6314-no-alg-assumption

BibTeX

@misc{warmtransfer-claim-sip-calls-drop-30-seconds-rfc6314-no-alg-assumption,
  title  = {Calls that drop after about 30 seconds: source note sip-calls-drop-30-seconds-rfc6314-no-alg-assumption},
  author = {{WarmTransfer}},
  year   = {2026},
  url    = {https://warmtransfer.net/knowledge/claims/sip-calls-drop-30-seconds-rfc6314-no-alg-assumption},
  note   = {Source note sip-calls-drop-30-seconds-rfc6314-no-alg-assumption, checked 2026-09-25}
}

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