# OpenAM Administration Guide
Chapter 9. Configuring Single Sign-On within One Domain

Sidebar | Prev | Up | Next

## 9.2. Cookies and the SSO Session Process

OpenAM uses cookies to track user sessions. The diagram shown next illustrates how OpenAM assigns and tracks cookies.

In the diagram:

- The domain shown in the description is `example.net`

- The protected resource application can be found on `app.example.net`

- The OpenAM server is located on `sso.example.net`.

[D]

A client points his browser to a protected resource application. An agent on the application checks the client browser cookies for the presence of a session ID, a component of an SSO Token. If such a Session ID exists and is valid, the agent requests validation (see arrow 8).

If no valid session ID currently exists, the agent redirects the client to OpenAM for authentication (AuthN). The client is then sent to OpenAM for AuthN. If the client submits valid credentials, the AuthN service creates a session cookie. The SSO Token and configured domain name is embedded in that cookie. OpenAM issues an HTTP redirect to send the client browser back to the protected resource. The SSO Token is actually a Java Object.

The agent then verifies the validity of the session with the OpenAM session service, before granting access.