Network Reliablity Using MPTCP

Improve Network Reliability by Leveraging Multipath TCP

When using app on an iOS device, users are likely to move in and out of range of Wi-Fi, switching to cellular networks and back again.

Multipath TCP improves the performance of our app when a user is in a location with limited Wi-Fi and while their device is transitioning to and from cellular data usage.

In its default configuration, a URL session uses a single radio for a network call, preferring Wi-Fi over cellular. However, with Multipath TCP enabled, the URL session initiates the request on both radios and selects the more responsive of the two with a preference for Wi-Fi.

Enable Multipath TCP in Project:

Enable the Multipath Entitlement in the Xcode Capabilities pane for your app target.
Set the multipathServiceType property in NSURLSessionConfiguration to a mode other than none.
Enable the Multipath Entitlement in the Xcode Capabilities pane for your app target.
- This can be done in Volt MX Iris using quantum_nitro_configuration.json which you can find in Assets -> Common -> Resource location.
- Set Multipath as true under Capabilities section.
Snippet:
```
{
    "iOS":{
    "KRelease":{
        "Capabilites":{
            "com.apple.developer.networking.multipath" : true
            },
            "BuildSettings":{
            }
            }
        },
    "Android":
    {
    }
}
```
Set the multipathServiceType property in NSURLSessionConfiguration to a mode other than none
- User needs to pass multipathServiceType using voltmx.application.setApplicationBehaviors API
Syntax:
```
voltmx.application.setApplicationBehaviors({
multipathServiceType:constants.MULTIPATHSERVICETYPE_HANDOVER
});
```

MultipathServiceType Constants

Constant
constants.MULTIPATHSERVICETYPE_NONE	None - no multipath (default).
constants.MULTIPATHSERVICETYPE_HANDOVER	Handover - secondary flows brought up when primary flow is not performing adequately.
constants.MULTIPATHSERVICETYPE_INTERACTIVE	Interactive - secondary flows created more aggressively.
constants.MULTIPATHSERVICETYPE_AGGREGATE	Aggregate - multiple subflows used for greater bandwidth.

By using any of the above mode other than none it will establish connection with MPTCP.

Platform availability:

iOS

Remarks:

Multipath TCP allows the connection to use several paths simultaneously. For this, Multipath TCP creates one TCP connection, called subflow, over each path that needs to be used.
MPTCP allows us to establish subflows over both of these connections, so applications can become independent from the underlying medium. Of course, latency and throughput of the subflows are different, but both provide network connectivity.

Advantages of Multipath TCP:

Reliability and connection persistency: It is possible to add or remove paths without connection loss.
Increased throughput: Every single connection through diverse path increase amount of available throughput.
Transparent for applications: Applications communicate the same way as on TCP.