Make your iOS app as responsive as Siri with NetReaktor

Have you ever noticed how barely Siri has connectivity challenges?


That is because Siri opens simultaneous connections over Wi-Fi & cellular using Multipath TCP.

Multipath TCP (MPTCP) is a TCP evolution that allows a data session to be conveyed over different access networks at the same time.

Since the implementation of MPTCP in iOS 7, Siri is able to seamlessly recover from failures of the cellular or WiFi interfaces that occur often when users are walking, a frequent scenario for Siri.

Measurements show that user feedback, time to first word, i.e. the time that the user waits before seeing a first word from Siri, for the 95th percentile is 20% faster.

It has also reduced the number of network failures by 5 times.

How to use MPTCP for your iOS app

In order to leverage MPTCP capabilities to improve network reliability of your iOS app, support is required at both the app and server level.

Since iOS 11, app developers can now support MPTCP at the client level.

Enable MPTCP in your app

Required steps on your side

Important notes

  •  For most cases, the handover mode is the best option. This mode provides your users with a seamless transition between Wi-Fi and cellular (4G or 5G), allowing uninterrupted usage of your app.
  • The interactive mode checks reliability of available networks and selects the most responsive access. Ideal for apps where low latency is critical.

Enable MPTCP at the server side

Key requirement

  • Multipath TCP requires the destination server to have Multipath TCP enabled. This is not available on standard Linux and Windows. It requires a custom version of the kernel.


  • If your server does not support MPTCP yet, contact us to know more about our MPTCP-ready server solution called NetReaktor.
    • It works as a proxy located before the destination server. 
    • It can run on standard cloud servers. No specific hardware required.

Examples of Apple apps leveraging the Multipath capabilities

Siri since 2013, Apple Maps and Apple Music since 2019.

Next apps using MPTCP: Yours?

Contact us & discover MPTCP benefits with our test app for FREE

Who we are

Tessares, founded in March 2015, is a technology company with a proven expertise in Multipath TCP (MPTCP), the standardised protocol used by iOS’ Multipath Services. It currently provides hybrid access solutions that improve Internet connectivity by combining DSL and 4G/LTE networks assets. The company is a spin-off from the UniversitĂ© Catholique de Louvain (UCLouvain) founded by pioneers of MPTCP.