Team-to-Team chat when SFB is homed on-premise

[VigilanteWang]

We have moved some users to TeamsOnly Mode(Hybrid connectivity all set). The rest of users are in Island mode. 

The question is: When 2 Island mode users having Team-to-Team chat/call, does the traffic go through the on-premise intranet, Specifically, does such chat interact with on-premise sfb servers just like sfb-to-sfb chat?

In this article, it says: 

Users who are homed on premises interact with on-premises Skype for Business servers

and

Teams users inherently have a Skype for Business home, whether they use Skype for Business or not. If you have on-premises Skype for Business users that are also using Teams (side by side), those users are homed on premises

[#2 · Accepted solution]

Hi,

As long we talk about within the organisation Teams chat will not go via Skype on-premises servers for Island users. If you are talking about federation (chat with users from other organisations) it will go via your servers.

When it comes to federation you will not be able to federate from Teams for Islands users homed in Skype4B On-Premises.