You are running a web server that is accessed by browsers from multiple mobile devices.
Due to the way TCP/IP works, connections can not be closed immediately. Packets may arrive out of order or be retransmitted after the connection has been closed. CLOSE_WAIT indicates that the remote endpoint (other side of the connection) has closed the connection. TIME_WAIT indicates that local endpoint (this side) has closed the connection. The connection is being kept around so that any delayed packets can be matched to the connection and handled appropriately. The connections will be removed when they time out within default period of four minutes.
Nevertheless, the number next to your TIME_WAIT statistic, 646750, is extremely excessive.
It means that 646750 connections were closed in the last 4 minutes, which makes 2694 per second!
Evidently, some of these mobile devices are heavily malfunctioning and are bombarding your server
with connections that are not being properly closed from the client side, or that you are serving an
enormous number of clients (which makes no sense for a single server).
If you are unable to isolate which mobile devices or application
are at the cause of the problem and to fix them,
you don't control the client side and can only alleviate the problem on the server side.
One parameter that can improve this congestion is TcpTimedWaitDelay, described as:
Determines the time that must elapse before TCP can release a closed
connection and reuse its resources. This interval between closure and
release is known as the TIME_WAIT state or 2MSL state. During this
time, the connection can be reopened at much less cost to the client
and server than establishing a new connection.
Reducing the value of this entry allows TCP to release closed
connections faster, providing more resources for new connections.
However, if the value is too low, TCP might release connection
resources before the connection is complete, requiring the server to
use additional resources to reestablish the connection.
TcpTimedWaitDelay can be modified by regedit at
It contains the number of seconds to wait. The default is 240 seconds (4 minutes).
Reboot is required if changed.
For example, changing to 30 seconds and with 2694 connections per second will mean that only
80820 connections will be waiting for close.
This number is still enormous, but the change will still reduce the usage of connection resources.