Strange issue to allow Web filtering on Skype for Business / Microsoft Lync

[heskez]

Hi, 

I've got a strange issue with a web filtering profile in relation to Skype for business URL's,. 

I've made a simple rule to allow ports TCP 50000-59999 and TCP 5061 (SIP implementation) and works all fine. 

Second I've made a rule to allow HTTPS to a range of Skype locations. And apply APP/IPS and SSL profile. 

I excempt the Skype URL's from scanning.

It works all fine. 

When I enable WEB/AV/DLP Profile it goes wrong. 

To resolve I've made a custom "Internet Telephony Custom" category and add the Skype URL's. 

I set the action to "Allow" within the Web filtering profile. 

I start debug on urlfilter enable and get result (ftgd-allow) from chache on the corresponding URL's which is good imo.

Nevertheless it still goes wrong (visible with RST within diag sniffer packet logs) and I can't logon in Skype 

when I enable the Web filtering profile. Same applies to AV and DLP Profile. 

Could this be a bug since it considers all three profiles?

Best,

E