Viewing Google free/busy calendar data in Exchange
How it works
The Google-to-Exchange free/busy sync can be broken down into two phases.
- Google moves f/b data from Google Calendar to an Exchange public folder database.
- Exchange users retrieve that f/b data from the public folder database and view it within Outlook calendar.
Phase 1: Moving f/b data from Google Calendar to the Exchange public folder
Once you've enabled interop, Google will automatically sync the f/b data of all Google Calendar users from Google to your Exchange public folder every 15 minutes. Google uses the Exchange Web Services URL and the username/password of the Exchange Role Account you entered in step #6 to gain access to your Exchange public folder.
Breaking down the Exchange public folder
Exchange needs to be able to match each Google user's f/b data with a unique Exchange identifier or else Exchange will not be able to know whose f/b data is whose. To do this, the Interop service labels each Google user's f/b data with his/her corresponding LegacyExchangeDN attribute value. The LegacyExchangeDN is the same value you have to enter into your Admin console in previously listed step #6.
After you create mail-enabled contacts for each Google Calendar user and add their LegacyExchangeDN's into your Admin console via step #6 of the Interop setup, Google will be able to store f/b data in the Exchange public folder and organize it by user.
Phase 2: Viewing Google f/b data in Outlook calendar
Once Google users' f/b data is stored locally in the Exchange public folder, Exchange users need to be able to view that data within Outlook calendar's free/busy scheduler. Outlook users can simply create a new event and click the Scheduling tab within a calendar event window, after which they'll be able to type the name of a G Suite user and then see their f/b data.
Breaking down Exchange's f/b data retrieval
Exchange can retrieve free/busy calendar data using a few different access methods, one of which is via a query to the public folder database. After an Exchange user clicks to view the Outlook free/busy scheduler, Exchange determines which f/b access method it will use based on the event attendee's availability address space, which corresponds to the domain in the attendee's email address (email@example.com). If the attendee's availability address space has been assigned the public folder database f/b access method, then Exchange will query the public folder whenever it looks up the attendee's f/b status.
Here's the problem. While the Interop service stores Google users' f/b data in your Exchange public folder database, Exchange's default f/b access method assigned to your primary domain name does not query the public folder database. As a result, Exchange will not find a Google user's f/b data if that user's email address is within your Exchange primary domain (and, thus, your default availability address space).
To fix this problem, we recommend adding your G Suite domain alias as a new availability address space in Exchange and assigning it the public folder f/b access method, as described in step #3 of our Interop configuration instructions.
Once you've created your availability address space, you can then create a mail-enabled contact in Exchange for each G Suite user whose free/busy data you want to sync to Exchange. You can create your mail-enabled contacts by following step #4 of our Interop configuration instructions.
Finally, when an Exchange user clicks in Outlook to view the f/b status of a Google user by using the mail-enabled contact created in step #4, Exchange will check the Google user's availability address space and notice that it needs to use the public folder access method to view the user's f/b data. After that, Exchange will access the public folder, find the Google user's f/b data based on the user's LegacyExchangeDN, and it will return the data to the Outlook user within the free/busy scheduler.