VoIP issue SIP ALG detected...?
-
Hi all,
PfSense 2.4.5 running on Hyper-V. Comcast static IP, Gig cable service. 15 Yealink phones accessing a CoreDial hosted PBX. Phone/Voice vendor was on site at my customer's office rolling out their phones and service. Asked me to make sure SIP ALG is disabled in pfSense. I know that the ALG is not implemented in pfSense. Set firewall to conservative mode and increased UDP timeouts per docs and JimP's excellent video on YouTube regarding VoIP and pfSense. Phones seem to be working fine but phone vendor says that as long as SIP ALG is detected they can expect voice quality issues, etc. Only thing I didn't do yet was the QoS traffic prioritization.
When on site, their tech ran a little command line utility on his laptop called sip-alg-detector.exe (I found it and got the same result too) which reports that SIP ALG is detected yet we know it isn't in pfSense. Does anyone know if there is something hidden in Comcast routers even when in bridge mode that can cause this to be detected, or is there anything else I can check in pfSense? I'm nearly out of ideas.
Thanks for any ideas!
Matt
-
@matty-ct said in VoIP issue SIP ALG detected...?:
Does anyone know if there is something hidden in Comcast routers even when in bridge mode that can cause this to be detected
Hi,
an idea
Many ISPs also use the SOHO routers / modems as public hotspots on an independent network, next to your internet connection. (+++SIP-ALG)
(this is especially true in larger cities)This feature works in addition to the device bridge mode or router mode, this does not matter.
Several known devices have FW-handling incorrectly with the SIP-ALG + hotspot (open wifi) function.You may have this problem as well...
BTW:
pfSense certainly doesn't do this, SIP-ALG
-
Problem solved. Had to call Comcast. As you suspected, even though the modem is in bridge-mode it still does NAT for the hot spot services and had SIP ALG on in some hidden area that is not customer facing. Comcast was able to disable and after a reboot the test utility came up clean.
Thanks for the hint.
Matt
-
@matty-ct said in VoIP issue SIP ALG detected...?:
As you suspected,
You welcome.
Somehow I felt this
