What is the Cassini Web server?The Cassini Web server is a simple, fully managed Web server that hosts ASP.NET. The Cassini Web server is a combination of the following:
- A simple HTTP listener that was built by using System.Net.Sockets.
- A hosting sample of ASP.NET that was built by using System.Web.Hosting APIs. This lets you host ASP.NET from any managed application.
What are some known functionality limitations of the Cassini Web server?
- It can host only one ASP.NET application per port.
- It does not support HTTPS.
- It does not support authentication.
- It responds only to localhost requests.
Does the Outlook client use Internet Information Server (IIS)?Microsoft Internet Information Server (IIS) is a Web server that includes configuration, logging, authentication, authorization, HTTPS support, multiple-site support, and performance and reliability tuning. It would require significantly more resources and would put an additional burden on the client computer if the Outlook client used IIS. Additionally, IIS requires local administrator privileges to be configured and adequately maintained. The Cassini Web server does not depend on IIS. However, it can run side-by-side with IIS depending on the configuration settings.
How does the Outlook client use the Cassini Web server?The Cassini Web server is installed during the installation of the Outlook client and is preconfigured to listen to port 2525. The CassiniPort registry setting must be set to 2525 so that the Outlook client can communicate with the Cassini Web server.
The Cassini Web server starts only when the Microsoft CRM Outlook toolbar is loaded in Microsoft Outlook. Therefore, the Cassini Web server runs within the Outlook process on the client computer. After Outlook closes, or after the CRMAddin.dll file is unloaded, the Cassini Web server unloads from the Outlook process.
The Outlook client uses the Cassini Web server to render the Microsoft CRM pages in Outlook. The .aspx pages are stored in the \Microsoft CRM\Client\res\web folder. Additionally, the .aspx pages are similar to the pages that are used by the Microsoft CRM Web site, except for certain code that is specific to the Outlook client.
The Outlook client pages are rendered by the Cassini Web server when the Outlook client is online or offline. The location of the data that is retrieved by the .aspx pages depends on the state of the Outlook client. If the Outlook client is online, TCP/IP is used to retrieve the data through SOAP calls to the Microsoft CRM server. If the Outlook client is offline, the data is retrieved through named pipes from the Microsoft SQL Server Desktop Engine (MSDE) database.