Solved SIP ALG Detected, Unknown Cause.

[bmadison]

Everything worked just fine until I switched ISP's. New ISP I am getting Detected SIP ALG. I can switch to old ISP and no error (I haven't shut off service to old ISP yet). UDM Pro SIP is disabled. Called New ISP to troubleshoot and was told to contact 3CX. Seems the only thing affected so far is Android Softphone, it is in a perpetual "Connecting..." state in top right corner.

• 3CX Version, 18.0.237
• Server OS, Raspberry Pi
• Is the 3CX Server Hosted and where? On-premises
• IP Phone Make/Model/Firmware version, Grandstream
• Provisioning Method: Loca
• Trunk Provider or VoIP Gateway Make/Model, Flowroute
• Has the Firewall Checker passed: Sort of
• Are custom Phone Templates being used: NO

 

[SweetAction]

If you are using the same network equipment except the ISP (and it's related modem) I would assume that the ISP itself is doing some SIP ALG and you will have to work with them on turning it off. It could also be some sort of Double NAT or CGNAT going on.

 

[bmadison]

Sent your reply to the ISP and they fixed it. It was a Double NAT.

Thank you.

 

[ChrisC_3CX]

Glad to hear you managed to sort this out!

Since everything now seems to be in order I'll be closing this thread.