User Unable to Login (On-Premise Skype)
Time to Execute: 45m
Kindly look if the correct DNS records are setup.
Look for AV records and CName External Access Edge Pool record.
Open cmd and type av.domain.com and look if they are pointing to the edge external ip addresses. And same for CName sip,domain.com and see if the output is the address of edge pool..
Further
For mobile client if wanted, create a lyncdiscover record which will point to reverse proxy..