Microsoft Exchange On-Premises - Calendar synchronization

  • Release version: Yokohama
  • Updated January 30, 2025
  • 5 minutes to read
    • Summarize
    Summarized using AI
    This content was generated using new OpenAI-powered functionality. Results are provided on an as is basis and are not guaranteed to be accurate or complete.

    Summary of Microsoft Exchange On-Premises - Calendar synchronization

    This feature enables ServiceNow customers to synchronize workplace reservations between the Workplace Reservation Management application and Microsoft Exchange On-Premises calendars. It supports bidirectional synchronization, allowing reservations made in either system to be reflected in the other. Because Microsoft Exchange On-Premises is accessible only within an organization's local network, synchronization relies on a MID server installed locally to communicate with the calendar provider securely.

    Show full answer Show less

    Key Features

    • MID Server Integration: Communication with the Microsoft Exchange On-Premises calendar is established via a MID server installed in the same local environment as Exchange. This setup enables secure and frequent synchronization.
    • Microsoft EWS Calendar Processor: A new calendar processor, Microsoft EWS, is included to support the on-premises calendar provider within the Workplace Calendar Synchronization application.
    • Synchronization from Workplace to Exchange: Reservations created in Workplace Reservation Management are synchronized to the on-premises Exchange calendar through the MID server using the Microsoft Exchange Server Spoke.
    • Synchronization from Exchange to Workplace: A scheduled job named WSDRS Sync Calendar items performs delta synchronization, retrieving incremental changes from Exchange calendars using synchronization tokens. This job is disabled by default and must be enabled and configured to run at desired intervals (default is every five minutes).
    • Synchronization Tokens and Pagination: Synchronization tokens serve as reference points to retrieve updates incrementally. Parameters like page size, sync batch size, and sync batch interval control the volume and frequency of synchronization requests.
    • Event Handling: Changes are translated into events (Create, Update, Delete, Read, Retrieve attendees) in ServiceNow for each reserved resource, enabling accurate reflection of calendar updates.
    • Strict Mode Option: When enabled, events are sent to a general email address instead of directly to employees' calendars. Employees receive invitations and can only modify reservations via Workplace Reservation Management, improving control over calendar changes.
    • Past Reservations Synchronization: Customers can synchronize past reservations by specifying start and end date/time ranges. Certain conditions apply, including activation of the calendar provider and reservable sync configurations. It is recommended to limit past events to fewer than 1000 per room to optimize performance.
    • 'No Request' Handling: This feature allows admins to generate and validate the payload for calendar events without making actual API calls to the calendar provider. It helps verify payload syntax before live synchronization.

    Practical Considerations for ServiceNow Customers

    • Ensure a MID server is installed and configured in the same local network as Microsoft Exchange On-Premises to enable communication.
    • Set up the Microsoft Exchange Server Spoke and create the necessary connection and credential aliases for authentication.
    • Activate and properly configure reservable sync records to enable synchronization and generation of synchronization tokens.
    • Enable and schedule the WSDRS Sync Calendar items job to automate inbound synchronization from Exchange to Workplace Reservation Management.
    • Use strict mode if you want to limit direct calendar event creation on employee calendars and prefer invitations via a general email address.
    • For synchronizing past reservations, ensure the configured periods and volume comply with recommended limits to avoid performance issues.
    • Note that the Workplace Reservations for Microsoft Outlook Add-in does not support Microsoft Exchange On-Premises integration.

    Create a connection with Microsoft Exchange On-Premises and synchronize reservations made using the Workplace Reservation Management application. You can synchronize all the reservations that are made using the Workplace Reservation Management to the On-Premises calendar and vice versa. The reservation synchronization from an On-Premises calendar to the Workplace Reservation Management is performed using various approaches like subscriptions, synchronization tokens, events, and occurrences.

    The Microsoft Exchange On-Premises, unlike other calendar providers, isn’t accessible online. The provider is remote and is accessible only by the organization locally. To synchronize calendar reservations with this on-premise setup, the Workplace Calendar Synchronization application enables you to communicate using the MID server. A MID server is installed in the same local setup where the Microsoft Exchange On-Premises is installed. This way, a communication can be established with the MID server and communicate frequently. To support the on-premises calendar provider, a new calendar processor, Microsoft EWS is supported in the Workplace Calendar Synchronization application.
    1. Connect MID server with ServiceNow®.
    2. Create a connection and credential alias.
    Important:
    The Workplace Reservations for Microsoft Outlook Add-in application does not support Microsoft Exchange On-Premises.

    Synchronization from Workplace Reservation Management to Microsoft Exchange On-Premises

    Synchronize reservations to the on-premises calendar from Workplace Reservation Management by communicating using the MID server.

    Synchronization from Microsoft Exchange On-Premises calendar to Workplace Reservation Management

    The reservation synchronization from the Microsoft Exchange On-Premises calendar to the Reservation portal is done by running a timely scheduled job, WSDRS Sync Calendar items.

    An approach called, Delta synchronization is used by the Workplace Calendar Synchronization application. With Delta synchronization, you retrieve only the incremental changes made on a resource email id of the calendar using a reference point called as synchronization token. That is, for each room (each reservable sync record), linked to the on-premises calendar provider you get the synchronization tokens, which are the reference points to get the update from the calendar in increments.
    • Based on the Page size, Sync batch size and the Sync batch interval, the information is retrieved by the synchronization tokens. For example, if you specified the values as 5, 500, and 60 respectively (in the previous fields). It means that you can raise 500 requests in an interval of 60 seconds. The synchronization results five changes in a page.
    • When you create a reservable sync configuration record under the on-premises calendar, you must ensure that is activated.
    • When the sync record is activated, a flow is triggered and a synchronization token for that reservable synchronization record is created in the Sync Deltas module.
    • The scheduled job, WSDRS Sync Calendar items, is provided with the application to get the latest changes for all the active reservable sync configurations. The scheduled job is set to False by default and it must be enabled to start synchronizing. By default, the scheduled job is set to run for every five minutes. However, you can set the scheduled job time as you want. At any time, you can also manually execute it.
    • The changes made on the reservable sync configurations are created as events in the Events module. The application creates Create, Update, Delete, Read, and Retrieve attendees events for Microsoft Exchange On-Premises calendar.
    • For each sync record, an event is created. Depending on the page size specified on the calendar provider, the changes are displayed. If there are any pending changes, it is displayed during the next scheduled job run.
    • The API that is used to get the synchronization tokens, saves the response in the Response field of the event. The API provides changes made on a single reservation, multi-reservation, and the parent recurring reservation.
    • Using the response created by the API, a reservation is created in the Workplace Reservation Management application.
    • With every scheduled job run, the synchronization token is also updated which is used as the reference point for the next synchronization.

    Strict mode

    The Workplace Calendar Synchronization application enables you to configure your connections and configurations with Microsoft Exchange On-Premises in strict mode as well. In strict mode, events are not directly created in an employee's calendar, instead, they are sent to a general email address. Employees are invited to the event. You can specify a strict mode email id through which you want to sync reservations. Employees can only make changes using the Workplace Reservation Management application.

    To enable strict mode, you can enable the Strict mode option in the while configuring the on-premises calendar provide. The requesters are considered as invitees.

    Synchronizing past reservations

    The Workplace Calendar Synchronization enables you to also synchronize reservations made in the past. You can specify the date and time range in the Sync start date time and Sync end date time fields. For the on-premises calendar, the following conditions must be met to sync past reservations:
    • The calendar provider that is the Microsoft Exchange On-Premises calendar provider that you configured must be active.
    • The Synchronize past reservations field must be selected.
    • The reservable sync configuration for which you want to sync past reservations must be active.
    Note:
    Ensure that the reservations that you want to sync from the past are not above 1000. If in cases the expected number of past events are more than 1000, it is recommended to modify the system property sn_wsd_rsvsync.ewsPastSyncPeriodInMonths. Specify the value in months keeping in mind the expected past reservations. A single sync syncs reservations from those many months. Ensure that the specified number of months do not have more than 1000 reservations per room/resource.

    'No request' handling

    No request is a mechanism to validate the generated syntax of the payload of an event created for the calendar. But, instead of sending the event to the calendar provider, it is only created. The admin can validate the payload content of the event (JSON) to ensure that is generated as expected. 'No request' ensures that the application does not make any API calls to the calendar provider when you create, update, or cancel a reservation in the Workplace Reservation Management application.