Inbound connections limit in Windows XP

For a Microsoft Windows 2000 version of this article, see
122920 .


At a computer that is running Windows XP or Windows 2000, when you attempt to connect to another Windows XP computer, you may receive the following error message:
No more connections can be made to this remote computer at this time because there are already as many connections as the computer can accept.


This behavior occurs if the computer reaches the maximum number of inbound connections that the computer can host.

In this case, when Windows 2000 client made a null session connection, the Windows XP based server counts this connection as one session. Therefore, the computer returns the error messages that are mentioned in the "Symptoms" section even if the computer connections are less than the session limit.

Note For Windows XP Professional, the maximum number of other computers that are permitted to simultaneously connect over the network is ten. This limit includes all transports and resource sharing protocols combined. For Windows XP Home Edition, the maximum number of other computers that are permitted to simultaneously connect over the network is five. This limit is the number of simultaneous sessions from other computers the system is permitted to host. This limit does not apply to the use of administrative tools that attach from a remote computer.

More Information

Any file, print, named pipe, or mail slot session that does not have any activity is automatically disconnected after the AutoDisconnect time has expired; the default for the AutoDisconnect time is 15 minutes. When the session is disconnected, one of the ten connections becomes available so that another user can connect to the Windows XP system. Therefore, lowering the AutoDisconnect time can help to reduce some of the problems that users may encounter with the ten-connection limit or the five-connection limit on a system that is not used heavily for server purposes.

You can configure the AutoDisconnect time by running the following command from a command prompt:
net config server /autodisconnect:time_before_autodisconnect
Specify the time in minutes.

Note The Windows Server service is self-tuning. Typically, the server configuration parameters are autoconfigured (calculated and set) each time you start Windows XP. If you run the net config server command in conjunction with the /autodisconnect, /servcomment or /hidden options, the current values for the automatically tuned parameters are displayed and written to the registry. After these parameters are written to the registry, you cannot tune the Server service by using the Networks tool in Control Panel. If you change any of the Server service settings, Windows XP can no longer automatically tune the Server service for your new configuration. To avoid losing the Server service's automatic self-tuning capability, make the change by using Registry Editor instead from a command line or from Control Panel.
All logical drive, logical printer, and transport level connections combined from a single computer are considered to be one session; therefore, these connections only count as one connection in the ten- connection limit. For example, if a user establishes two logical drive connections, two Windows sockets, and one logical printer connection to a Windows XP system, one session is established. As a result, there will be only one less connection that can be made to the Windows XP system, even though three logical connections have been established.

The only way system A will have multiple sessions to another system, system Z, is if system A is running services that create logical connections to system Z. For example, if a user is logged on to system A as guest and a service is running on system A under the user1 account, and both the user and the service (as user1) establish connections to system Z, two sessions are established. Each logon session that uses the Server service counts against the connection limit.

Per development: The connection limit refers to the number of redirector-based connections and is enforced for any file, print, named pipe, or mail slot session. The TCP connection limit is not enforced, but it may be bound by legal agreement to not permit more than 10 clients.

For more information about Inbound connections limit in Windows 2000, click the following article number to view the article in the Microsoft Knowledge Base:

122920 Inbound connections limit in Windows


Article ID: 314882 - Last Review: Sep 23, 2011 - Revision: 1

Microsoft Windows XP Home Edition, Microsoft Windows XP Professional