IP Communicator calls to phones no one can hear me

[rogerssa]

Been trying to figure out why when myself or my users are connected via VPN and call in to another phone no one can hear me.

The funny part of this is that if I call and leave a user voice mail it works just fine.  If I call any cell phone with IP communicator they can hear me just fine.  It is only when I make a call from phone to phone.  If I'm connected directly on the network it does work just fine.  

So yes I believe it is something with my Fortinet Firewall and the VPN.  But I just can't figure it out.  I would think they should never hear me, but when it works ok to voicemail and to other phones I'm just confused as can be.

Shane

[TomMar1]

It is most likely incoming UDP traffic being blocked by the FW.

Best thing to do would be monitor FW traffic in real time and see what is being blocked.

UDP ports in the range 16384 to 32764 need to be allowed

[rogerssa]

I had made sure all incoming was allowed from the VPN to internal networks.  

I had NAT turned off for some reason for that same policy.  I just turned it back on and now it is all working perfectly.  

Shane

[TomMar1]

Glad it works now, but tighten your incoming rule set up if indeed you are allowing ALL incoming VPN traffic to ALL internal networks.  I would only allow specific protocols and ports to the necessary networks.

[rogerssa]

I agree I will tighten it up. VPN has to be allowed and authenticated with 2 factor. So I only have a handful of users that can access VPN. If someone tries to access VPN that isn't allowed I get email instantly of an attempt.  I do plan to lock it down to just a few protocols today as well to make it better.