Source note · SIP ALG problems on firewalls and routers
In the Fortinet technical tip, default-voip-alg-mode under config system settings defaults to proxy-based. Setting it to kernel-helper-based disables the FortiGate SIP ALG.
Checked 2026-09-25
- Vendor
- Fortinet
- Product
- FortiGate (FortiOS)
- Subsystem
- VoIP inspection
- Deployment
- on-premises
- Region
- not restricted
- Release range
- FortiOS 5.x era per 2015 tip; later releases unconfirmed
- Checked
- 2026-09-25
Sources
- Technical Tip: Disabling VoIP Inspection — Fortinet (Fortinet Community technical tip authored by Fortinet staff) · tier 2 current vendor documentation · Step 2 Disable SIP-ALG
Cite this note
APA
WarmTransfer. (2026, September 25). SIP ALG problems on firewalls and routers: source note sip-alg-problems-fortigate-voip-alg-mode. WarmTransfer. https://warmtransfer.net/knowledge/claims/sip-alg-problems-fortigate-voip-alg-mode
BibTeX
@misc{warmtransfer-claim-sip-alg-problems-fortigate-voip-alg-mode,
title = {SIP ALG problems on firewalls and routers: source note sip-alg-problems-fortigate-voip-alg-mode},
author = {{WarmTransfer}},
year = {2026},
url = {https://warmtransfer.net/knowledge/claims/sip-alg-problems-fortigate-voip-alg-mode},
note = {Source note sip-alg-problems-fortigate-voip-alg-mode, checked 2026-09-25}
}