365 UC
Published in

365 UC

What doesn’t work in Microsoft Teams if you’re hosted in Skype on-prem?

If there ever was a blog post borne out of learning something on the fly, it’s this one.

Okay, before I start, when I talk about SfB* coexistence modes, I mean any of the SfBWithTeamsCollab, SfBWithTeamsCollabAndMeetings or SfBOnly coexistence modes. I don’t want to type SfBWithTeamsCollab about a million times. I might also refer to SfBWithTeamsCollab as ‘collab mode’.

So, long story short, we’ve moved the vast majority of our users over to SfBWithTeamsCollab coexistence mode. We still have a few on Islands mode, and we have a few test users in TeamsOnly mode.

With regards to Skype, we’re still predominantly running Skype for Business Server 2015, in hybrid. We have about 1000 people in Skype Online, but there is another long and boring story why we haven’t moved everyone yet.

So, it’s been about a week since the change to ‘collab mode’ for the vast majority of users. This is what I’ve learned about having people spread across the various coexistence modes as well as across Skype on-prem and Skype Online…

Issues with chat and presence

So, what do some of these No’s look like in the Teams client:

When an Islands mode/Skype on-prem user tries to chat with a SfB* mode/Skype on-prem user it (kind of) correctly sees that the user is a Skype user:

However, when the user clicks on the “Continue your conversation here” link it never converts to a Skype interop chat. This means the SfB* user cannot be reached.

Presence is also broken and shows a strange nonsensical date:

Things are slightly different when the recipient is in Skype Online. The presence now works:

However, the chat still doesn’t work and in actual fact when clicking the “Continue your conversation here” link the chat windows just disappears?


So far, I’ve only focused on communications within my own tenant. The affects on Federation are also affected by the location of the Skype profile. In fact, if you’re an Islands user and hosted on-prem, the effects are even worse. This table shows that an Islands user using Teams with Skype on-prem can’t contact anyone via Federation:

This table was taken from Bryan Nyce’s video, which can be seen on YouTube here. Go watch it.


So, how can you avoid some of these scenarios?

  1. Move everyone to Skype Online. Of course, this is easier said than done.
  2. If you’re only just starting to look at Teams, get the coexistence mode changed to SfB* as soon as you can (DO IT NOW!). By all means change people to Islands mode to test all the features, but let them know about all the shortcomings up front. If you leave Islands mode out there too long, people will see the change to SfB* mode as taking something away, despite your best efforts explaining otherwise.
  3. If using SfB* coexistence modes with Skype on-prem, try not to have anyone in Islands mode.
  4. Don’t use the coexistence modes at all. Go from Islands to TeamOnly overnight. This would be very unlikely in anything larger than a small org.
  5. Would it be better if users in SfB* modes didn’t see any presence at all in Teams? If they can’t chat or call, why do they need presence, especially as they have to use Skype for all that? It would certainly minimise the presence issues seen when in SfB* mode.



Get the Medium app

A button that says 'Download on the App Store', and if clicked it will lead you to the iOS App store
A button that says 'Get it on, Google Play', and if clicked it will lead you to the Google Play store
Matt Ellis

Unified Communications guy, Pompey fan, burger eater, coffee drinker...