Poly CCX Phones and Time
Came across an annoying issue with Poly CCX Teams phones this week, so worth documenting here briefly to save others the same pain. In short: The phones log into Office 365 and MUST have the time accurate to within 5 minutes, otherwise they will not log on. Indeed, if they drift, they will stop working. Out of the box, they will try and get time over NTP from time.windows.com, and fall back to north-america.pool.ntp.org. If you do not have port 123 open to the Internet from the network where the phones will sit, then you can get them to look at an on-prem NTP server, but there is a major gotcha. You can configure DHCP scope option 42 to point at your on-prem NTP server (usually, in a Windows environment, a local domain controller) however that's not enough - you also need to tell the phone NOT to override this setting: because out of the box, it does . So to get a phone working in such an environment, you may need to follow these steps (assuming you do have Scope Option 42 appro