Disable the SIP Application-level Gateway (ALG)

Publisher

Palo Alto Networks

URL

https://docs.paloaltonetworks.com/ngfw/administration/app-id/disable-the-sip-application-level-gateway-alg

Published

2026-09-24

Updated

unknown

Accessed

2026-09-25

HTTP status

200

License

Palo Alto Networks copyright; all rights reserved; no-redistribution; short excerpts and locators only

Source notes citing this source

• Palo Alto Networks states that when a VoIP client application has NAT intelligence embedded, the firewall's SIP ALG can interfere with signaling and cause the client application to stop working. in context
• On Palo Alto Networks NGFWs, the SIP ALG is used to open dynamic pinholes in the firewall where NAT is enabled. in context
• To disable the SIP ALG on a Palo Alto Networks NGFW, go to Objects > Applications and select the sip application. Choose Customize for ALG in the Options section, check Disable ALG, click OK, and commit. in context
• Registration failures attributed to SIP ALG plausibly come from Contact or Via rewriting that conflicts with the endpoint's own NAT handling. The collected vendor sources state interference in general terms but do not document a registration-specific mechanism. inferred in context

Cite this source record

APA

WarmTransfer. (2026, September 24). Disable the SIP Application-level Gateway (ALG). WarmTransfer. https://warmtransfer.net/knowledge/sources/paloalto-docs-disable-sip-alg

BibTeX

@misc{warmtransfer-paloalto-docs-disable-sip-alg,
  title  = {Disable the SIP Application-level Gateway (ALG)},
  author = {{WarmTransfer}},
  year   = {2026},
  url    = {https://warmtransfer.net/knowledge/sources/paloalto-docs-disable-sip-alg},
  note   = {Palo Alto Networks, accessed 2026-09-25}
}