Enable Free/Busy information between the Office 365 users from two different tenants, when the Autodiscover of one of them is pointing On-Premise


Introduction:

If your organization has 2 major tenants under which user population is getting migrated, since the users would be placed into 2 different tenants free/busy information sharing is not enabled by default. Following document introduces the options and steps which are needed in order to have the Free/busy information shared between 2 tenants.

 

What is Free/Busy data?

Free/busy data is information about the availability of individuals within an organization at specified times. The user status data indicates whether the time period specified is free, busy or tentative, or if the user has set their out of office status. However, the data contains no explanatory information, such as whether the user is in a meeting or has a personal appointment or whether they are physically in the office at the requested time.

 

What is the Organization relationship?

In order to setup a free/busy sharing between the two tenants, it is required that a New organization relationship needs to be created - An organization relationship is a one-to-one relationship between businesses to allow users in each organization to view calendar availability information. When it is set up, Administrator is actually setting level of information that the users in the external organization can view. The external organization may set up the same or different settings on their side.

 

Scope of this article:

This article only covers the steps that are required in order to enable Free/Busy information sharing between the Office 365 users from two different tenant. This articles does not cover the topic of sharing the On-Premise Free/Busy information with Office 365 users or On-premise to On-Premise Free/Busy sharing between two hybrid infrastructures.

This articles covers the activation of Free/Busy information between ContosoEU.onmicrosoft.com (a European tenant) and ContosoNA.onmicrosoft.com (a North America tenant).

 

Configuration Part:

Configuration of the free/busy information can be broken into two part and those are:

a) Initial configuration

b) Managing the configuration

 

Initial Configuration:

Following are the steps which can be followed in order to setup the Organization relationship.

On the European tenant

  1. From the Office 365 admin center dashboard, go to Admin > Exchange.
  2. Go to Organization > Sharing.
  3. Under Organization Sharing, click New .
  4. In New organization relationship, in the Relationship name box, type a friendly name for the organization relationship as “Contoso EU to Contoso NA tenant”
  5. In the Domains to share with box, type the domain for the external Office 365 or Exchange on-premises organization as ContosoNA.onmicrosoft.com.
  6. Select the Enable calendar free/busy information sharing check box to turn on calendar sharing with the domains. Set the sharing level for calendar free/busy information and set which users can share calendar free/busy information.

To set the free/busy access level, select one of the following:

  • Calendar free/busy information with time only.
  • o   Calendar free/busy with time, subject, and location.
  1. Click save to create the organization relationship.
  2. Once the setup is completed, Organization relationship should show up the following information auto populated into it.
  3. Also make sure that all the federated domains are well populated into the Organization relationship.

 

On the US tenant:

  1. From the Office 365 admin center dashboard, go to Admin > Exchange.
  2. Go to organization > sharing.
  3. Under Organization Sharing, click New .
  4. In new organization relationship, in the Relationship name box, type a friendly name for the organization relationship as “Contoso NA to Contoso EU tenant”
  5. In the Domains to share with box, type the domain for the external Office 365 or Exchange on-premises organization as contosoeu.onmicrosoft.com
  6. Select the Enable calendar free/busy information sharing check box to turn on calendar sharing with the domains. Set the sharing level for calendar free/busy information and set which users can share calendar free/busy information.

To set the free/busy access level, select one of the following:

  • Calendar free/busy information with time only.
  • Calendar free/busy with time, subject, and location.
  1. Click save to create the organization relationship.
  2. Once the setup is completed, Organization relationship should show up the following information auto populated into it.                         
  3. Also make sure that all the federated domains are well populated into the Organization relationship.

 

Managing this configuration:

When the initial setup is completed, it would be necessary to make sure that all the new domains which are getting added into the O365 are participating into the Organization relationship and in order to update the information onto the Organization relationship here are the steps.

  1. From the Office 365 admin center dashboard, go to Admin > Exchange.
  2. Go to organization > sharing.
  3. Double click on the Organization Relationship which has been created – type in the domain name into the section “Enter a domain here” and Press + button
  4. Click save to complete configuration

 

How to know if this has worked:

After the configuration is completed Free/busy availability details should be visible across both the tenants –any O365 users in the EU or NA tenant should be able to see the free/busy information of any EU/NA tenant user.

 

Important:

Taking into consideration that the new organization relationships were created for the vanity domains, ContosoEU.onmicrosoft.com – in the US tenant and ContosoNA.onmicrosoft.com – in the EU tenant, the new domains should be added automatically. However, recommendation process is to double-check the settings of the concerned organization relationship once a new domain will be added in the US or EU tenant

How does the Organization Relationship works in this scenario?

By creating the organization relationships with the vanity domains, all the Office 365 users from these two tenants will be able to see their Free/Busy information, based on the MFG token and here is the flow of how it actually works.

  1. A user who is in the ContosoEU tenant requests Free/Busy information for User1@contosona.com (which is on the NA tenant) This request is made at the Exchange online.
  2. The Exchange online will now lookup its organizational relationships and verify if it has one for contosona.com.
  3. Now, the Exchange online will contact the Microsoft Federation Gateway and request an authentication token for contosona.com.
  4. The MFG sends back a token because contosona.com has a trust relationship with the MFG.
  5. The Exchange Online now uses the information it obtained from the Organization Relationship to do an Autodiscover request for this domain, in order to retrieve the remote Exchange Web Services endpoint it should connect to. It then uses the address that is received to send the Free/Busy request to.
  6. Exchange Online of the NA tenant will first check whether the MFG token which the Exchange EU tenant has sent across with is valid before accepting the Free/Busy Request.
  7. It will also verify its organization relationship so that it knows what information it is allowed to return.
  8. Once the above checks are completed, the mailbox of User1@contosona.com will be queried for the Free/Busy information.
  9. Exchange Online of NA tenant will send back the Free/Busy information to the EU tenant, once it will be successfully obtained.
Comments (7)

  1. Vijay Jadi says:

    Hello Dragos, excellent effort to bring up this piece of work into a form of technet blog.

    I would be really happy to see if you could modify the title a bit to concentrate on autodiscover part as well – where its pointing to the on-premise.

    Rest part looks wonderful – would look forward to work with you again.

  2. Harihara Sudhan says:

    @Dragos Nita ,well done !!

  3. Vinayak says:

    This article about Limitations of free/busy sharing says that https://technet.microsoft.com/en-us/library/dd638083(v=exchg.150).aspx – free/busy availability lookups for Office 365-based or remote users that have been moved to the cloud will fail

    Exchange organizations that have both on-premises and cloud users   If you set up calendar sharing with another Exchange organization that is configured in a hybrid deployment with Microsoft Office 365, free/busy availability lookups for Office 365-based or remote users that have been moved to the cloud will fail. Because the organization relationship for your Exchange organization is with the remote on-premises Exchange organization, not the Office 365-based Exchange Online organization, the free/busy request can’t query the Office 365-based users. Exchange 2013 doesn’t support functionality to proxy these availability requests through the on-premises organization to the Office 365 service.

  4. Matthew_a_Noob says:

    The title of this article is “Enable Free/Busy information between the Office 365 users from two different tenants, when the Autodiscover of one of them is pointing On-Premise” but in the body of the article you state, “This articles does not cover the topic of sharing the On-Premise Free/Busy information with Office 365 users or On-premise to On-Premise Free/Busy sharing between two hybrid infrastructures.”
    The title drew me in but then I wished I got what I came for.

  5. jeff says:

    I needed to set TargetAutodiscoverEpr $null before Free/Busy worked in O365 pulling Free/Busy from an Exchange 2013 server.
    https://mikeparker365.wordpress.com/2016/06/17/manually-setting-freebusy-endpoint-for-exchange-hybrid/

  6. Alfredo Saavedra says:

    Great article!

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