UPDATE: Microsoft have changed their stance on support for TLS 1.0 and 1.1 within Office 365 post October 31st 2018. From this date, TLS 1.0/1.1 will not be supported, but devices still using these will not be blocked from connecting to Office 365. Read more about it here.
Ahhhh fond memories. I recall with much joy the first time I deployed Lync Phone Edition (LPE) devices, all those years ago (not that long ago: 2010 to be precise). In the Lync world, for many years these were the only devices you could deploy for end users, meeting rooms or common areas where a physical handset was a requirement.
How times have changed.
The approach Microsoft took to providing devices that natively registered to Lync was simple: Microsoft provided the code (known as Aries, which ran on Windows CE 6.0), and vendors (Polycom, HP, Aastra) provided the functional phone components around it: Microsoft controlled the software stack (responsible for support and updates), and the vendors looked after the rest. These devices were known as Lync “Optimized” devices. However, it soon became apparent that making phones was not core to Microsoft’s business, and there were plenty vendors out there that did it better. It was around the end of 2011 that we first began to see “Compatible with Lync” handsets from Polycom and others start to hit the market.
As covered by Polycom’s Jeff Schertz here, “Compatible with Lync” handsets were devices that moved away from using a Microsoft provided and supported codebase, and towards using devices manufactured by 3rd parties that understood the finer nuances of telephony design. The software stack was owned and developed by each vendor, with each undertaking Third Party Interoperability Program (3PIP) certification before their devices were given the seal of approval from Microsoft to register against Lync. Looking at the broader ecosystem of 3rd party software and devices that integrate with Skype for Business, this was the model Microsoft moved forward with until recently, where we have begun to see the Microsoft developed and supported software stack start to take centre stage again, Surface Hub, Skype Room System, Microsoft Teams devices… (a topic for another blog…)
So, since 2011, we have had handsets available that were not based on Aries code which we could deploy to end users. LPE device support continued, with Support for LPE devices registering natively to Skype for Business Online also supported. This however will soon cease to be the case.
The Discontinuation of Support for TLS 1.0 and 1.1 in Office 365
As outlined here, Microsoft is dropping support for Transport Layer Security (TLS) versions 1.0 and 1.1 in Office 365 from October 31st 2018.
Why is this an issue you ask?
Windows CE 6.0 does not support anything above TLS 1.0. This is of course the underlying Operating System in use on LPE devices, so as of the end of October, if you have LPE devices, they will no longer be able to register against Skype for Business Online.
But I’m still using on-premises Lync/Skype for Business. Does this affect me?
If you’re still using on-premises Lync/Skype for Business infrastructure to support your end users, you have some wiggle room, but also take into account where your Exchange environment is. Are you using Lync/Skype for Business on-premises but Exchange Online? Your phones will sigh in, but any Exchange interop (voicemail, meeting invites etc) will cease to function. I would also add that it would be considered best practice to disable TLS 1.0/1.1 on your on-premise servers and enjoy added piece of mind of using a stronger security suite. Optional of course.
What devices are affected?
- Polycom: CX500, CX600, and CX3000
- Hewlett-Packard: 4110 and 4120
- Mitel-Aastra 6721ip and 6725ip
I Use On-Premises Lync/Skype for Business: How many LPE devices do I have?
A very good question, and I’m glad you asked. Luckily, the team at Insync Technology have put together a free tool that will tell you exactly how many LPE devices you have out there! So simple!
To get access to the tool, check our the rest of this blog here: http://blog.insynctechnology.com.au/still-using-lync-phone-edition-devices-you-better-read-this

Looks like the link to the tool above is broken / taken down. Can you advise if this tool is still available?
Hi Keith,
This tool no longer exists sorry. Check out Get-CsConnections (https://www.ucunleashed.com/269) if you want to find out how many LPE devices you have registered against your on-prem servers.