In an advisory, the company said it was likely that there would be many dependencies and connectivity considerations that had to be taken into account, before use of TLS 1.2 was possible in Office 365.
TLS is a cryptographic protocol that provides communications security over a computer network.
One poster to the Linux Users of Victoria mailing list said video conferencing equipment installed at his workplace for use with Skype 4 business as part of an Office 365 migration did not use TLS 1.2 and hence did not work.
"I don't believe that there will be any great impact," he said. "When we discussed this on the LUV list in 2016 the case for supporting older versions of TLS was not strong and the incidence of such old software will have decreased since then.
"However a follow-up post to the list mentions newly released hardware that doesn't support TLS 1.2 so it will cause problems for some people."
The Microsoft advisory said there were three scenarios for which one needed to plan:
- Lync/Skype client connectivity to Office 365;
- On-premises server integration w/Office 365; and
- Third-party integration with Skype for Business Online.
The advisory provides detailed advice about possible issues and how to avoid them.
"Now that Microsoft has officially dropped support for older and less secure protocols there's no reason for anyone else to support them for general use (i.e. for a website supporting random visitors)," Russell said.
"But I expect some people running intranet servers will keep supporting older systems."
The advisory said: "Your organisation’s environment may be comprised of various networking or security devices that may include proxy servers and load balancers, or other networking components. Be sure to validate TLS 1.2 supportability, test carefully, and contact the vendor if needed."