Increasing number of sessions on RDesktop

superuser.com/questions/118272/how-can-i-configure-the-max-connection-limit-for-remote-desktop-connections
Windows 2003 by default allows the RDP connections to administer the server remotely. But if you want more users to login and work on the same, you need to make it as a Terminal Server and you also need to buy licenses for your clients that connect to it.
It is called CALs and it can be either per device or per user. So if you have 5 licenses, you'll be able to connect to that server the way you want.
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Run Command-Type gpedit.msc-Click on Computer Configuration -Administrative Templates-Windows Components-Terminal Service and Increase the "Limit Number of Connections"
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You will need to install Terminal server on your system. Go to Administrative tools, then Configure your server, and follow the wizard to make your system a Terminal server. At that time, the concurrent connections are virtually unlimited
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allow users to connect remotely using Terminal Services 
Specifies whether to allow users to connect remotely using Terminal Services.
You can use this setting to configure Terminal Services remote access for the target computers.
If the status is set to Enabled, users can connect to the target computers remotely using Terminal Services. You can limit the number of users who can connect simultaneously by configuring the "Limit number of connections" setting or the "Maximum Connections" option on the Network Adapter tab in the Terminal Services Configuration tool.
If the status is set to Disabled, the target computers maintain current connections, but will not accept any new incoming connections.
If the status is set to Not Configured, Terminal Services uses the "Allow users to connect remotely to your computer" option on the target computer to determine whether remote connection is allowed. This option is found on the Remote tab in System Properties.
 Start a program on connection
Configures Terminal Services to run a specified program automatically upon connection.
You can use this setting to specify a program to run automatically when a user logs on to a remote computer.
By default, Terminal Services sessions provide access to the full Windows desktop, unless otherwise specified with this setting, by the server administrator, or by the user in configuring the client connection. Enabling this setting overrides the "Start Program" settings set by the server administrator or user. The Start menu and Windows Desktop are not displayed, and when the user exits the program the session is automatically logged off.
To use this setting, in Program path and file name, type the fully qualified path and file name of the executable file to be run when the user logs on. If necessary, in Working Directory, type the fully qualified path to the starting directory for the program. If you leave Working Directory blank, the program runs with its default working directory. If the specified program path, file name, or working directory is not the name of a valid directory, the terminal server connection fails with an error message.
If the status is set to Enabled, Terminal Services sessions automatically run the specified program and use the specified Working Directory (or the program default directory, if Working Directory is not specified) as the working directory for the program.
If the status is set to Disabled or Not Configured, Terminal Services sessions start with the full desktop, unless the server administrator or user specify otherwise. (See Computer Config\Administrative templates\Windows Components\System\Logon\"Run these programs at user logon" setting.)
Note: This setting appears in both Computer Configuration and User Configuration. If both settings are configured, the Computer Configuration setting overrides.