Configure the Number of Simultaneous Sessions Supported

Updated: March 24, 2010

Applies To: Windows 7, Windows 8, Windows Server 2008, Windows Server 2008 R2, Windows Server 2012, Windows Vista

You can use this procedure to change the number of Telnet sessions the Telnet Server service will support.

By default, Telnet Server supports two simultaneous connections.

Membership in the local Administrators group, or equivalent, is the minimum required to complete this procedure.

To change the port number used by Telnet Server

  • At a command prompt, type the following, and then press ENTER:

    tlntadmn [\\server] config maxconn=Number:

    • \\server

      The name of the computer running Telnet Server whose simultaneous connection limit you want to change. If this parameter is not present, then the command runs against the Telnet Server service installed on the local computer.

    • config maxconn=Number

      Specifies the maximum number of connections. You must specify this number with a positive integer that is smaller than 10 million.

Formatting legend

Format Meaning


Information that the user must supply


Elements that the user must type exactly as shown

Between brackets ([])

Optional items

Additional considerations

  • Tlntadmn.exe must be run at a command prompt that was opened by using the Run as administrator option. If you do not run it at an elevated command prompt, you receive an Access is denied message.

  • The Tlntadmn.exe tool is installed with Telnet Server, so it might not be present on a computer that does not have Telnet Server installed.

  • You can determine the current number of connections supported by Telnet Server by running the command:

    tlntadmn [\\server]

    Windows displays several current settings, including the current maximum connections number.

See Also


Enable the Telnet Server Service
Grant Access to a Telnet Server
Configure Telnet Server Authentication
Configure Telnet Server to Allow Administrator Access by using Password Authentication
Configure the Command Interpreter Used by the Telnet Server
Configure the TCP Port Number Used by Telnet Server
Configure Idle Session Timeouts for Telnet Sessions
Configure the Domain Used for User Name Authentication