@natalie @pidgin Yes and no.

#SkypeForBusiness is the only #SelfHosting & #OnPremise option and like #Atlassian with #Jira, #Microsoft does discourage non-"#Cloud" / "#SaaS" deployments anew but they still honour existing #licenses and don't want to mess with big licensees that do #VolumeLicensing to pay for thousands of licenses in bulk.

I wish I could go into more detail but that's as far as I can go barring #NDA|s *unless summoned by court or regulators like @bsi ...