SystemConfig_Network class

This class is the event type class for network events.

The following syntax is simplified from MOF code.

Syntax

[EventType(17), EventTypeName("Network")]
class SystemConfig_Network : SystemConfig
{
  uint32 TcbTablePartitions;
  uint32 MaxHashTableSize;
  uint32 MaxUserPort;
  uint32 TcpTimedWaitDelay;
};

Members

The SystemConfig_Network class has these types of members:

• Properties

Properties

The SystemConfig_Network class has these properties.

MaxHashTableSize

Data type: uint32

Access type: Read-only

Qualifiers: WmiDataId(2)

The size of the hash table in which TCP control blocks (TCBs) are stored. TCP stores control blocks in a hash table so it can find them very quickly.

MaxUserPort

Data type: uint32

Access type: Read-only

Qualifiers: WmiDataId(3)

The highest port number TCP can assign when an application requests an available user port from the system. Typically, ephemeral ports (those used briefly) are allocated to port numbers 1024 through 5000.

The value for the highest user port number TCP can assign is controlled by a registry setting. For more information, see MaxUserPort.

TcbTablePartitions

Data type: uint32

Access type: Read-only

Qualifiers: WmiDataId(1)

The number of partitions in the Transport Control Block table. Partitioning the Transport Control Block table minimizes contention for table access. This is especially useful on multiprocessor systems.

TcpTimedWaitDelay

Data type: uint32

Access type: Read-only

Qualifiers: WmiDataId(4)

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.

RFC 793 published by the IETF requires that TCP maintains a closed connection for an interval at least equal to twice the maximum segment lifetime (2MSL) of the network. When a connection is released, its socket pair and TCP control block (TCB) can be used to support another connection. By default, the MSL is defined to be 120 seconds, and the value of this entry is equal to two MSLs, or 4 minutes. For more information, see RFC 793.

Reducing the value of this entry using a registry setting 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.

Normally, TCP does not release closed connections until the value of this entry expires. However, TCP can release connections before this value expires if it is running out of TCP control blocks (TCBs). The number of TCBs the system creates is controlled by a registry setting. For more information, see MaxFreeTCBs.

Requirements

Requirement	Value
Minimum supported client	Windows Vista [desktop apps only]
Minimum supported server	Windows Server 2008 [desktop apps only]

See also

SystemConfig