ControlChannelTriggerStatus ControlChannelTriggerStatus ControlChannelTriggerStatus ControlChannelTriggerStatus Enum


Specifies if the system was able to complete configuration of a ControlChannelTrigger object for use by class elements in the Windows.Networking.Sockets and related namespaces.


This enumeration is not supported on Windows Phone.

public : enum class ControlChannelTriggerStatus
enum class winrt::Windows::Networking::Sockets::ControlChannelTriggerStatus : int32_t
public enum ControlChannelTriggerStatus
Public Enum ControlChannelTriggerStatus

Windows 10 requirements

Device family
Windows Desktop Extension SDK (introduced v10.0.10240.0) Windows Mobile Extension SDK (introduced v10.0.10240.0) Windows 10, version 1803 (introduced v10.0.17134.0)
API contract
Windows.Networking.Sockets.ControlChannelTriggerContract (introduced v1) Windows.Foundation.UniversalApiContract (introduced v6)


HardwareSlotAllocated HardwareSlotAllocated HardwareSlotAllocated HardwareSlotAllocated 2

A hardware slot was allocated by the system.

HardwareSlotRequested HardwareSlotRequested HardwareSlotRequested HardwareSlotRequested 0

The policy check succeeded and a hardware slot has been requested from the system.

PolicyError PolicyError PolicyError PolicyError 3

A policy error occurred when the system tried to complete configuration of a ControlChannelTrigger. This error can occur when an app has requested more connections for hardware or software slots than are permitted by system policy.

ServiceUnavailable ServiceUnavailable ServiceUnavailable ServiceUnavailable 6

The service provided by the ControlChannelTrigger is unavailable. This can happen if the network connection broker service is not yet ready but the app is trying to establish a ControlChannelTrigger channel. This status code is provided under the following conditions:

  • When there is fast user switching and the new user is trying to establish the ControlChannelTrigger channel.
  • When the system is entering a low power mode (Connected standby mode) and the app is trying to create a software slot. Software slots are available only when the system is active and not in low power mode.

The mitigation in both these cases is to listen for System Event broker events and register the ControlChannelTrigger channel at that point.

SoftwareSlotAllocated SoftwareSlotAllocated SoftwareSlotAllocated SoftwareSlotAllocated 1

The policy check succeeded and a software slot was allocated by the system.

SystemError SystemError SystemError SystemError 4

A system error occurred when the system tried to complete configuration of a ControlChannelTrigger for a hardware slot.

TransportDisconnected TransportDisconnected TransportDisconnected TransportDisconnected 5

The network transport associated with the ControlChannelTrigger was disconnected. The underlying TCP connection was already disconnected by a TCP reset received from the remote destination or a graceful disconnect by either the app or the remote destination. The most common occurrence is a TCP reset or a graceful disconnect sent by the remote destination.


The system maintains a policy on the number of ControlChannelTrigger instances that can be configured for a UWP app, to limit resource usage and extend battery life. Once configuration by the system is complete, each ControlChannelTrigger instance represents either a hardware or software slot for an established TCP connection that is to be maintained even when the app is suspended (moved from the foreground to the background).

A local computer system can be in several power states:

  • System active
  • Connected standby
  • Shutdown An app in the system active mode can receive a control channel trigger when either a software or hardware slot is used. An app in the connected standby mode can only receive a control channel trigger when a hardware slot is used.

See also