Question about Interop, SfB<>Teams


When a Teams user in Teams-only mode IMs a SfB user (on-prem with hybrid enabled) who is in Islands mode, should the IM go to Skype?  All we see is a missed IM in the recipient's mailbox.

24 Replies
Would it be possible to somehow declare that we'd like the IM to go to Skype instead of the Teams Contact? We can respond to IMs from Skype users but can't initiate the conversations.
This will be a tough challenge for us also. Recommendations are if you have SFB Online, to keep people in Islands mode until you get to the "event horizon" of having enough people on Teams Only. Then, switch everyone. BUT, Teams Only people will NOT be able to chat with SFB users in Islands mode IF that SFB person doesn't use Teams also UNLESS the SFB user initiates a conversation every 30 days.
Ok, so after the SfB user initiates a chat, the Teams user can then initiate chats to the SfB user after that for a window of 30 days? Where did you find this info?
So you're seeing this issue as well? Teams -> SfB chat doesn't work unless that SfB user first chats the Teams user?
The idea here is to use Skype Only mode for those users so the messages from Teams users get routed over. If they plan to use both clients but you don't want chat, then the newer Skype for Business with Teams (collab only) or (Collab with meetings) would be the way to go. The question is when those modes will be functional because I don't think they are rolled out fully just yet!

IMHO Interop is a MESS between SFB & Teams, not even including hybrid.

We're piloting Teams now, were in 'Islands' Mode at the org level, and things started really screwing up - IM's initiated from 'UpgradeToTeams' users sent to 'Islands' users in SFB would send an email to the user, inviting them and giving them links to upgrade/DL Teams.


I fixed this by switching the org to SkypeOnly, and my users who have Teams in the wild are now complaining about cross-platform IM/Presence issues.  These people, however have not been upgraded and I've been telling them to use SFB until they get their upgrade notice.

'Islands' is no longer recommended apparently, despite the guidance given as recently as Ignite.

This is indeed expected behavior.  I ran into this same scenario during my testing of the different policies.  A Teams client in 'TeamsOnly' mode will not be able to initiate a chat to a SFB user.  However, the Teams client can receive chats from the SFB user.  Take that same teams client out of 'TeamsOnly' mode and back into 'Islands' mode and then the Teams client will be able to initiate a chat with a SFB client.


I'm trying to find the MS article that backs this up, but I am having difficulties locating it at this time.  I'll update my post or write a new post if I am able to find it.

The issues is you guys are all using Islands, it's supposed to route to Teams to Teams no matter what, that's what Islands is designed to do. You have to setup Skype Only and Teams only if you want to have one and the other with cross chat etc. Soon as you start with Island Mode you dig yourself into a hole that's not fun to get out of as you have discovered!

Official MS documentation states that chat is possible in TeamsOnly mode with Skype for Business users as long as Teams users are also Skype Online users.

best response confirmed by Kevin TRELOHAN (MVP)

Hey Guys, 
Those of you going through coexistence and upgrade scenarios I HIGHLY HIGHLY HIGHLY recommend watching these video's. I went through these the other day and they are so informative and will answer many of the questions you guys have and are very detailed in the way interop should work and the modes and all of that!


The recordings are located here

yes " Interoperability only supports basic chat and calling between Skype for Business and Teams, and interop escalation scenarios for desktop sharing and multi-party chat and calling" from here
So we have started testing Skype only mode, but it does not work as intended. Our test user is still getting chats that originate from Teams delivered to his Teams client, and is still able to sign into Teams.

On the MS interop documentation, I see this:
Skype for Business only
In this coexistence mode, users remain in Skype for Business—not Teams—for chat, meeting and calling capabilities, and they don’t use Teams for teams and channels. This mode is available today; however, in the current implementation Teams modalities are not turned off for the user automatically. This capability is upcoming. In the interim, admins can remove the Teams license for any users who need to stay in Skype for Business as their only communications application.

So - does this mean that in addition to moving the user to Skype only upgrade policy, we must remove the Teams feature from their enterprise license for the time being?
When you set Skype Only did you use Powershell to set the users etc or the GUI? Using powershell to set Skype Only works better than using the GUI as it doesn't really seem to do anything with interop, but setting powershell from what I've seen sets the IM routing sent from a Teams user should go to the users Skype for Business if you use Powershell to set the upgrade policy.

The thing that article is talking about is the reverse of Teams only mode, where if you try using Teams it basically says your organization isn't using Teams yet, you need to use Skype for business click here.


We're still grappling with this.  SFBOnly at the org level caused its own issues with IM/Presence, and so my director had me reset the org to Islands.   

While t-shooting with the org in SFBOnly, I worked on a ticketed escalated to SevA/CritSit with a MS Engineer who provided me with the table below on the routing of IM's from/to clients depending on the mode the users are in.  I found it very helpful in testing. 





I took the opportunity to ask deep/probing questions based on what has been discussed herein by others.  She was extremely helpful so I thought I'd share some of my takeaways:  


  1. The version of Office you're running can impact what you see in SFB when you are switched to TeamsOnly.  (Awaiting Final confirmation and req'd minimum SFB Build if possible).  Later builds will block SFB access, but earlier ones allow you to use SFB/Teams interchangeably w/o alerts, further muddying the routing t-shooting waters. 
  2. Once a user is cut over to SFBOnly, I was told there is a 14-day cache period that must expire for the users' new status to be shown in the org (the 'this user is using SFB and some Teams Features may not be available' banner, as well as the little 'S' SFB icon beside their name in the Chat section).  Upon asking, I was told there was no way to manually force/expedite this cache flush.
  3. A SFBOnly user's presence change can take up to 4 mins to be reflected in a TeamsOnly user's Teams client.
  4. A TeamsOnly user's presence update is updated on a SFBOnly users SFB Client <5 seconds.  
  5. From TeamsOnly, a SFBOnly User's 'true' presence status can only be initiating a new chat. 

Scenarios & expected behaviors with Tenant in SFBOnly Mode and some users have individual user policy set to TeamsOnly:

 User A = SfBOnly upgrade policy per tenant policy

User B = TeamsOnly User


  1. If UserA initiates chat from SfB it will land in user UserB's Teams client. When User B replies, User A will receive in SfB
  2. If UserA accesses the Teams client and initiates a conversation to UserB, the chat will go to Teams and if the UserB continues to use that Teams thread the messages will continue to go to Teams even for the SfBOnly user.  However, if User B create a new chat, it will route to UserA's SfB client.
  3. A TeamsOnly user should not use existing chat threads. They should initiate a new chat via the icon that has a pencil at top left of search, to ensure routing will go to intended recipient. This should be done for all chats in Teams as most users are SfBOnly in tenant but may have used Teams.  New Chat will make sure the chat is going to route to recipient's SfB client. If UserB does not initiate a new chat thread, it is possible they are using an old chat thread where the UserA was using Teams.
  4. To easily identify the routing in the Teams client, Teams user will see a banner at top of the conversation indicating the recipient is using SfB (again so long as the Teams user has initiated a new chat per #2 above).
  5. It is possible to have both Teams - Teams chat threads and Teams-Skype Chat threads in the Teams client depending on when the chat thread was created and who created them. Skype chats are identified in recent chats with a "S" for Skype beside user name.
  6. Presence in Teams is polled and could take up to 4 minutes to be updated - hence when a SfB user manually changed his presence and was in an Active chat with a Teams user, the Teams client took more than 5 seconds to update the SfB user's presence.
  7. User B shouldn't be able to initiate chat via Skype client (I am able to do so however, and that might be a function of an old Office/SFB Client build)

I don't like Islands, but I have no choice at this point.  We have an older office build too... <grrrr>

HTH, all.  This info is current from a Teams/SFB CritSit engineer as of yesterday (12/19/2018) - YMMV depending on your Ring, Office, slight breezes, or a butterfly flapping its wings in the Amazon...    \_(ツ)_/¯ 




That is inaccurate. It's only true if there is already a chat open. TeamsOnly users cannot start a new chat to the SFB client of an Islands user.


Several aspects here.

First, at this point when you set SfBOnly, you also *must* set chat off in messaging policy, calling off in calling policy, meetings scheduling off in meeting policy. We intend to greatly simplify this soon.

Second, there is some latency in the actual application of the policy. If you want to test without the latency, you can exit Teams and remove the store (cached values) from %appdata%\Microsoft\Teams

Rob, I am not sure about the 30 days?


That said, if you need interop, your users should not be in Islands but in one of the interop modes.

John, our guidance has not changed from Ignite. From your comments it seems some aspects are unclear, let me try and clarify.

You stated: "IMHO Interop is a MESS between SFB & Teams, not even including hybrid.

We're piloting Teams now, were in 'Islands' Mode at the org level, and things started really screwing up - IM's initiated from 'UpgradeToTeams' users sent to 'Islands' users in SFB would send an email to the user..."

This is by design. We have repeated there is no interop in Islands. You have an island of SFB and an island of Teams and no bridge between them.

If you want interop you need to have users in one of the interop modes. This was described at length for example in session BRK3142 at Ignite. What we said there is still 100% valid.
Thank you