IVR block Meraki FIREWALL

[ITGOOKULAMKMK]

We are implemented Interactive Voice Response (IVR), but when we try to call from outside, we can’t get any voice assistance—only silence—and the call connects to the primary number. Our IVR team is trying to rectify this issue, but unfortunately, they reported that it was caused by a blocked firewall. I didn’t get any block log from the firewall. Can you help sort out this issue?

[cmr]

Have they told you what ports need to be open (5060?) and to where?  Do you already have a rule similar to the above that includes some internal hosts, but not others?

[ITGOOKULAMKMK]

They did not assign any port; they use a SIP line.

[IvanJukic]

Hi @ITGOOKULAMKMK ,

If your MX firmware is release 18.2 and newer you can use the Firewall Log monitoring tool. This will display the if the traffic is blocked or not. 

https://documentation.meraki.com/MX/Firewall_and_Traffic_Shaping/Firewall_Logging

You can also check the Firewall rules as well, just in case there is no traffic when using the Tool.

https://documentation.meraki.com/MX/Firewall_and_Traffic_Shaping/MX_Firewall_Settings

[ITGOOKULAMKMK]

HI @IvanJukic ,

  we are using MX64 

Restricted from versions 18.200 and higher

[IvanJukic]

Hi @ITGOOKULAMKMK 

Thanks for letting me know. So if the call connects and you get silence. Most likely the  RTP streams (it carries the audio) are being blocked or dropped.
So, check for things like (1:1 NAT, port forwarding, etc) on the Firewall. Also, have your team check the logs on the PBX/Platform for any NAT/Port issues.

[van604]

Thanks @IvanJukic for this info, didn't know this.  just stumbled onto this tidbit

[IvanJukic]

No problem at all @van604 ...

It is fairly new feature and sometimes I forget it is there. But when I do remember, it saves me a lot of time, going through pcaps & logs.