According to Fortinet, from FortiOS 5.2 the FortiOS proxy-based SIP ALG handles all SIP traffic by default. In FortiOS 5.0 the SIP session helper applied when no VoIP profile was applied.

Checked 2026-09-25

Since FortiOS v5.2, the FortiOS proxy/ALG handles all SIP traffic by default.
Vendor
Fortinet
Product
FortiGate (FortiOS)
Subsystem
VoIP inspection
Deployment
on-premises
Region
not restricted
Release range
FortiOS 5.0 and 5.2
Checked
2026-09-25

Sources

Cite this note

APA

WarmTransfer. (2026, September 25). SIP ALG problems on firewalls and routers: source note sip-alg-problems-fortigate-52-proxy-default. WarmTransfer. https://warmtransfer.net/knowledge/claims/sip-alg-problems-fortigate-52-proxy-default

BibTeX

@misc{warmtransfer-claim-sip-alg-problems-fortigate-52-proxy-default,
  title  = {SIP ALG problems on firewalls and routers: source note sip-alg-problems-fortigate-52-proxy-default},
  author = {{WarmTransfer}},
  year   = {2026},
  url    = {https://warmtransfer.net/knowledge/claims/sip-alg-problems-fortigate-52-proxy-default},
  note   = {Source note sip-alg-problems-fortigate-52-proxy-default, checked 2026-09-25}
}

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