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# multipathServiceType

A service type that specifies the Multipath TCP connection policy for transmitting data over Wi-Fi and cellular interfaces.

```
var multipathServiceType: URLSessionConfiguration.MultipathServiceType { get set }
```

## Discussion

Multipath TCP, defined by the IETF in [RFC 6824](https://tools.ietf.org/html/rfc6824), is an extension to TCP that permits multiple interfaces to transmit a single data stream. This capability allows a seamless handover from Wi-Fi to cellular, aimed at making both interfaces more efficient and improving the user experience.

The [`multipathServiceType`](/documentation/Foundation/URLSessionConfiguration/multipathServiceType-swift.property) property defines which policy the Multipath TCP stack uses to schedule traffic across Wi-Fi and cellular interfaces. The default value is `none`, meaning Multipath TCP is disabled. You can also select handover mode, which provides seamless handover between Wi-Fi and cellular.

Multipath TCP requires server support. Resources for Linux-based systems are available at <https://mptcp.dev>.

---

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