KES 12.3.0.493 for Windows breaks 3CX

[COPE IT]

Hi,

After updating to KESB 12.3.0.493 for Windows through yesterday, our 3CX calls are now badly impacted.  There are a number of methods of using 3CX; Windows app, Microsoft Store desktop app, "Electron" Desktop app (soon to be deprecated) and Web browser.

With the Windows app, I am now unable to dial any target (voicemail, other extension or outside line).  It immediately hangs up as "call failed".

In both the new Microsoft Store app version and Web browser, these are allowed to dial, but call quality is poor and very quiet, despite microphone input level being at maximum.

I uninstalled KESB 12.3.0.493 and immediately all call functions and audio quality was restored under 3CX.

Reinstalled KESB 12.3.0.493 and all problems with 3CX returned.

Any suggestions as to how to remedy this, perhaps by policy etc?  Or does this need a code/database fix from Kaspersky?

Thanks

Edited January 11 by COPE IT

[Demiad]

Hello again

Try temporarily disabling SSL inspection. Set the option "Do not scan encrypted connections": https://support.kaspersky.com/kes-for-windows/12.3/175124

If the result is ok, return the SSL-inspection settings. Then add a VOIP server address(-es) exception for SSL-inspection: https://support.kaspersky.com/kes-for-windows/12.3/175151

[COPE IT]

Hi Demiad - thanks for your suggestions.

We already have SSL inspection disabled under our settings.  The setting is locked from end-user editing as set by policy on the Admin Server.

In the Policy, we have defined a small set of Trusted web addresses which are local services on the LAN, defined by DNS or IP addressing.  Our 3CX (VoIP) server is included in this list (by wildcard on local sub-domain addresses).

I have two policies, one for the majority of users, and one for my small Developer team, where we needed to add a couple more trust exclusions.

However, that trust list was not getting pushed down to the client computers under this policy, which was apparently because the setting was not "locked" to prevent end-user adjustments.

I tested locking the setting in the policy, applying the policy and reloading 3CX - it then worked OK.  (I had to re-unlock the setting and reaply in order to review the list under the local KES setting to confirm that it now had the exclusions list, then go back and lock it again and reapply).