---
title: isViable
framework: networkextension
role: symbol
role_heading: Instance Property
path: networkextension/nwudpsession/isviable
---

# isViable

The viability of a UDP session represents whether or not data can be transferred.

## Declaration

```swift
var isViable: Bool { get }
```

## Discussion

Discussion Evaluates to true if the session can read and write data, false otherwise. Use Key-Value Observing to watch this property.

## See Also

### Monitoring the session state

- [state](networkextension/nwudpsession/state.md)
- [NWUDPSessionState](networkextension/nwudpsessionstate.md)