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Cisco TMSXE dual integration with Office 365 and on-premise exchange


I have a question on what to do when you are migrating from an Exchange on-premise solution to an Office 365 environment and how to integrate Cisco TMS and TMSXE into both solutions while migration occurs?

I am running 

TMS Version 14.6.1

TMSPE Version 1.4.1

TMSXE Version 4.1

CUCM 10.5.2

About 50 plus CTS and TC Code endpoints

All of our users are used to scheduling via exchange calendars and the Excahnge administrators has said that Office 365 users can only book on-premise calendars as tentative.

I need to test moving all the rooms/calendars to Office 365, but can find no answers on this which is why I have come to the professionals.

Cisco TAC has told me that a dual integration is in no way supported, which leads me to the question of how I achieve a dual integration without disrupting services for our users?


CJ Guinn

2 Replies 2


This is what I got back from Cisco on the Hybrid deployment:

Office 365 may be deployed in combination with on-premises Exchange servers. Cisco TMSXE supports combining Exchange servers on-premises and in the cloud provided that:

  • On-premises Exchange servers are either Exchange 2013 (recommended) or Exchange 2010.
  • Active Directory is on premises, which is required to work with Cisco TMS. Cisco TMSXE must access the same

Active Directory as Cisco TMS.

  • All users are in the same environment (on premises or Office 365) as the room mailboxes they will book, and the WebEx Scheduling Mailbox, if applicable. This is due to a Microsoft limitation on hybrid deployments. Note that the same service user can be used cross premises. For more information on these Microsoft limitations, see the Microsoft support article Cross-premises Calendar editing is unavailable in a hybrid deployment of Exchange Online in Office 365 and on-premises Exchange Server.

Note that the above limitations on cross-premises booking also apply to environments where Exchange is transitioning from on-premises to cloud or from cloud to on-premises. 

Chenna Krishna
I am looking for same integration now. What i found is, we have to enable CAS in TMSXE and need to point Auto discover to CAS server in TMSXE. If mailbox not found in On Premises Exchange CAS server will forward requests to Cloud ( Office 365). We don't have to do anything in TMSXE end.

I hope it helps.
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