Before Skype for Business Online can the utilized properly, DNS needs to be configured to direct client applications and federated organizations to the Skype for Business Online environment in Microsoft Office 365. To ensure proper entry of the required records, you may need to contact your DNS hosting provider to make the necessary changes.
This document covers public DNS entries. If for some reason, an agency has a DNS zone in their internal name servers for their SIP domains, the records below will need to be put in place there, as well.
These autodiscover records allow Skype for Business Online clients across all platforms to automatically discover the settings necessary to connect to Office 365. Without this record, clients may not be able to consistently connect to Skype for Business Online. This must be in place for each domain name used to sign into Skype for Business Online.
Use the following records:
lyncdiscover
webdir.online.lync.com
sip
sipdir.online.lync.com
_sip
_tls
100
10
443
sipdir.online.lync.com
_sipfederationtls
_tcp
100
10
5061
sipfed.online.lync.com