Technical Tip: Disabling VoIP Inspection

Publisher

Fortinet (Fortinet Community technical tip authored by Fortinet staff)

URL

https://community.fortinet.com/t5/FortiGate/Technical-Tip-Disabling-VoIP-Inspection/ta-p/194131

Published

2015-03-27

Updated

unknown

Accessed

2026-09-25

HTTP status

200

License

Fortinet copyright; all rights reserved; no-redistribution; short excerpts and locators only

Source notes citing this source

• 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. in context
• After changing FortiGate SIP handling, the tip says to clear existing SIP sessions (filter on destination port 5060 and clear) or reboot the unit. in context
• The same Fortinet tip also removes the SIP session helper. You list entries under config system session-helper and delete the entry that handles SIP. The entry number, 13 in the tip's example, varies by device. in context
• The Fortinet tip states that re-enabling the FortiGate SIP ALG requires a restart. in context
• Fortinet's 2015 technical tip says the FortiGate SIP ALG should be disabled only for troubleshooting, to isolate a problem. Cisco instead recommends switching SIP ALG off for Webex Calling as standing practice. disputed in context
• 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. in context

Cite this source record

APA

WarmTransfer. (2015, March 27). Technical Tip: Disabling VoIP Inspection. WarmTransfer. https://warmtransfer.net/knowledge/sources/fortinet-community-disabling-voip-inspection

BibTeX

@misc{warmtransfer-fortinet-community-disabling-voip-inspection,
  title  = {Technical Tip: Disabling VoIP Inspection},
  author = {{WarmTransfer}},
  year   = {2015},
  url    = {https://warmtransfer.net/knowledge/sources/fortinet-community-disabling-voip-inspection},
  note   = {Fortinet (Fortinet Community technical tip authored by Fortinet staff), accessed 2026-09-25}
}