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# CFNetwork Constants

Constants for use with CFNetwork.

## Topics

### Constants

[`let kCFHTTPVersion3_0: CFString`](/documentation/CFNetwork/kCFHTTPVersion3_0)

HTTP version 3.0.

[`let kCFStreamNetworkServiceTypeAVStreaming: CFString`](/documentation/CFNetwork/kCFStreamNetworkServiceTypeAVStreaming)

A multimedia audio and video streaming service.

[`let kCFStreamNetworkServiceTypeResponsiveAV: CFString`](/documentation/CFNetwork/kCFStreamNetworkServiceTypeResponsiveAV)

A responsive, time-sensitive, multimedia audio and video service.

[`let kCFStreamNetworkServiceTypeResponsiveData: CFString`](/documentation/CFNetwork/kCFStreamNetworkServiceTypeResponsiveData)

A responsive, time-sensitive data service.

[`let kCFStreamPropertyAllowConstrainedNetworkAccess: CFString`](/documentation/CFNetwork/kCFStreamPropertyAllowConstrainedNetworkAccess)

A Boolean value that indicates whether connections may use the network when the user has specified Low Data Mode.

[`let kCFStreamPropertyAllowExpensiveNetworkAccess: CFString`](/documentation/CFNetwork/kCFStreamPropertyAllowExpensiveNetworkAccess)

A Boolean value that indicates whether connections may use a network interface that the system considers expensive.

[`let kCFStreamPropertyConnectionIsExpensive: CFString`](/documentation/CFNetwork/kCFStreamPropertyConnectionIsExpensive)

A Boolean value that indicates if the connection is using a network interface that the system considers expensive.

### Macros

[`#define CFN_EXPORT`](/documentation/CFNetwork/CFN_EXPORT)


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