---
title: ecn
framework: network
role: symbol
role_heading: Instance Property
path: network/nwprotocolip/metadata/ecn
---

# ecn

A specific Explicit Congestion Notification flag value to set on an IP packet.

## Declaration

```swift
var ecn: NWProtocolIP.ECN { get set }
```

## See Also

### Sending IP Options

- [init()](network/nwprotocolip/metadata/init().md)
- [NWProtocolIP.ECN](network/nwprotocolip/ecn.md)
- [serviceClass](network/nwprotocolip/metadata/serviceclass.md)