Appliance Access is Denied and Webex audio problems

Question

Hi there, Need your help and expertise. We have an HA here with Sophos XGS2300 (SFOS 19.5.3 MR-3-Build652). The following problem occurs in particular with Webex Audio / Video. From external to internal and vice versa, the audio and video channel is established without any problems. However, if the employees at the same location call each other directly, no audio/video channel is established. Even if the corresponding firewall rule is set to Any / Any as a test. No UDP is blocked by the DOS protection. What we see is that almost at the same time there are "Appliance Access Denied" actions. 
 We do not have this behavior with MS Teams or any other VoIP provider. We are currently at a loss as to what this could be. 
 Thanks for any help. Stefan

LuCar Toni · Answer

Try to play with the SIP settings. Looks like Webex wants to do SIP: https://docs.sophos.com/nsg/sophos-firewall/20.0/help/en-us/webhelp/onlinehelp/AdministratorHelp/RulesAndPolicies/FirewallRules/VoIPSIPModuleTurnOnOff/index.html

Vivek Jagad · Answer

Hi StefanS , Thank you for reaching out to the community, You can also try to prioritize this via SD = REF: Sophos Firewall: How to prioritize the traffic via SD-WAN for the applications

Appliance Access is Denied and Webex audio problems

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