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# handleOutboundData(from:readBytesStartOffset:readBytes:)

Make a filtering decision about a chunk of outbound data.

```
func handleOutboundData(from flow: NEFilterFlow, readBytesStartOffset offset: Int, readBytes: Data) -> NEFilterDataVerdict
```

## Parameters

`flow`

An [`NEFilterFlow`](/documentation/NetworkExtension/NEFilterFlow) object containing information about the flow.

`offset`

An unsigned integer containing the offset of the data stored in `readBytes`. This offset is measured from the beginning of the flow’s outbound data.

`readBytes`

An <doc://com.apple.documentation/documentation/Foundation/NSData> object containing the data to be filtered.

## Return Value

An [`NEFilterDataVerdict`](/documentation/NetworkExtension/NEFilterDataVerdict) indicating how the system should handle the chunk of data and all subsequent outbound data for the flow.

## Discussion

`NEFilterDataProvider` subclasses must override this method.

---

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