Managing Internet Calendar Sharing in Exchange Server 2010 Service Pack 1 (Part 1)

If you would like to read the next part in this article series please go to Managing Internet Calendar Sharing in Exchange Server 2010 Service Pack 1 (Part 2).

In this article we will cover all server aspects of the deployment, while in the next article we will be validating the Internet Shared Calendar functionality on the client side and also how to integrate with Live Calendar.

Introduction

Exchange Server 2010 Service Pack 1 release brought a lot of new features to the table (by the way, this article is based on the Beta version available on the Internet) and in this article we will cover Internet Calendar Sharing with Internet users. Exchange Server 2010 RTM allows federated calendar between Exchange Server 2010 organizations (or at least an Exchange Server 2007 organization with an Exchange Server 2010 CAS just for Federation would work as well) where it increases the collaboration not just among users within the same organization but among different companies.

Now, Exchange Server 2010 SP1 goes beyond the company federation and allows end-users to share and retrieve calendars on the Internet in a secure and controlled way. There are two layers of security when we are talking about Calendar Sharing: the first layer is the organization level where the Exchange Administrator sets the boundaries for the Calendar Sharing; the second layer is at user level where the user can restrict a little bit more what was permitted at the Organization level. Users can easily go through OWA for instance and reduce the time window, the amount of information to be available, and their own calendar permissions. That is, either restricted or public available.

In order to provide Internet Calendar Sharing in Exchange Server 2010 Service Pack 1 and allow integration with common Internet calendars such as Live and Yahoo. Also, basing it on the iCalendar standards (RFC 2445), keep it secure and anonymous a new Virtual Directory was added to the current OWA structure, as shown in Figure 1. This new Virtual Directory has only Anonymous Authentication enabled and makes easier to an end-user to navigate in a Shared Calendar using the same Outlook Web App experience.

Figure 1

Managing Internet Calendar at Organization and CAS level

On the server side we have two different items to play with:

CAS Server and Organization configuration.

The first requirement is to enable and configure the external URL on your OWA Virtual Directory. In order to do that we can open Exchange Management Console, expand Microsoft Exchange On-Premises (<ServerName>), expand Server Configuration, and click on Client Access. Then, let’s select the desired Client Access server on the right panel, and double click on owa (Default Web Site) on the Outlook Web App tab.

In the General tab of the OWA properties, we can set the External URL by just typing in the information, as shown in Figure 2.

Figure 2

Note:
If for some reason you change your External URL you have to ask your users or at least create a script/cmdlet to stop and start publishing their calendar to get the new URLs.

The second phase of the Server level configuration will occur on the CAS Servers facing the internet where we must make sure that Internet Calendar Publishing is enabled. The attribute that we are looking for is the CalendarPublishingEnabled attribute, in order to have Internet Calendar functionality the value must be set to True. In order to retrieve the current value we can use several different ways, here we can see a couple of possible options:

• To list the Calendar of all CAS Servers:
  Get-OWAVirtualDirectory | Select Name, Server, Calendar*
• To list the information from a specific server (Figure 3)
  Get-OWAVirtualDirectory –Server <ServerName> | Select Name, Server, Calendar*
  

Figure 3

Now that we know how to list and validate if the server is correctly configured for Internet Calendar Sharing, we may have to enable the feature using the following options:

• To change all servers:
  Get-OWAVirtualDirectory | Set-OWAVirtualDirectory –CalendarPublishingEnabled:$true
• To change a specific server specifying the server on the Set-OWAVirtualDirectory cmdlet
  Set-OwaVirtualDirectory -Identity “<ServerName>\owa (Default Web Site)” -CalendarPublishingEnabled:$true
• To change a specific server without specifying the ServerName\VirtualDirectory we could use the first cmdlet specifying the server in the first cmdlet to facilitate the process:
  Get-OwaVirtualDirectory -Server <ServerName> | Set-OwaVirtualDirectory -CalendarPublishingEnabled:$true
  

The last step is to configure a Sharing Policy to allow Internet Sharing Calendar and define the level of information will be available to the end-users. The most important thing is that the domain must be set to Anonymous and any of these values for security are valid: Calendar Sharing with free/busy information only, Calendar sharing with free/busy information, plus subject and location, or Calendar sharing with free/busy information, plus subject and location and body.

We will be examining some examples of these three levels in a little bit.

The above explanation is shown in Figure 4, it does not matter if we are changing an existent policy or creating a new one from scratch but essentially the information entered will be similar to Figure 4.

Figure 4

Enabling Internet Calendar to all users

Now that we know how to configure the Sharing Policy in order to have Internet Calendar going, it’s time to demonstrate how to enable it to all users of your organization. The first step is to change the Default Sharing Policy. From the Exchange Management Console, follow these steps:

1. Open Exchange Management Console
2. Expand Microsoft Exchange On-Premises (<ServerName>)
3. Expand Organization Configuration
4. Click on Mailbox
5. Click on Sharing Policies tab
6. Double click on Default Sharing Policy
7. Select the existent Domain listed and click on Edit. Change the Domain to Anonymous and Action based on your requirements. Also make sure that Enable Sharing Policy setting is enabled, as shown in Figure 5.

Figure 5

8. Click on OK. You may receive a warning dialog box saying “Warning: You’re allowing users to access the feature that lets them publish their calendars. Make sure that the Calendar virtual directory has been enabled on the Client Access Servers so that published calendars will be accessible”, click OK.

It will work for all users that do not have any other Sharing Policy associated with their mailbox. By default all users are associated to the Default Sharing Policy, as shown in Figure 6.

Figure 6

Enabling Internet Calendar Sharing using a different policy

Another way to deploy Internet Calendar Sharing is creating a new Sharing Policy and then associating the new policy with a specific set of users. These are the steps that can be performed to achieve this solution:

1. Open Exchange Management Console
2. Expand Microsoft Exchange On-Premises (<ServerName>)
3. Expand Organization Configuration
4. Click on Mailbox
5. Click on Sharing Policies tab
6. Click on New Sharing Policy…
7. In the Introduction page. Type in the new policy name, and define the permissions and domain (Anonymous for Internet Calendar) as we’ve just seen in the previous section (Figure 7) and click Next.

Figure 7

8. In the Mailboxes page (Figure 8). Select mailboxes that will be set with this new policy. Let’s associate just a single user to start testing and then click Next.

Figure 8

9. In the New Sharing Policy page. A summary of all configuration that we have defined so far will be displayed, just click New.
10. In the Completion page. We will see the cmdlet used to create the new Sharing Policy and also a cmdlet for each user defined in the previous steps to receive the new Sharing Policy.

Conclusion

In this first article we covered all steps required to enable Internet Calendar Sharing in an Exchange Server 2010 SP1 organization. In the article to follow, we will be reviewing the client side of this process and integrating it with Internet Calendar solutions, such as Live and Yahoo.

If you would like to read the next part in this article series please go to Managing Internet Calendar Sharing in Exchange Server 2010 Service Pack 1 (Part 2).