Open source contributions

Integrating MPTCP in the mainline Linux kernel

(MARCH 2019)

Contributors from Tessares: Matthieu Baerts & Benjamin Hesmans


The Tessares founders were among the key developers of the open-source implementation of Multipath TCP in the Linux kernel that is available from This implementation is considered by the IETF as the reference implementation of Multipath TCP, but it is not included in the mainline Linux kernel. Tessares contributes to the maintenance of this implementation and ports the bug fixes to different kernel versions.

New open-source MPTCP version built by Tessares is available here:
(last version based on a v4.9.x kernel because we recently switched to v4.14.x on master)

Note that there is also a new v0.94.3 version based on a v4.14.x kernel:

Engineers from Tessares, Apple, Intel, RedHat are actively developing a new Multipath TCP implementation that will eventually be merged in the mainline Linux kernel. You can follow this ongoing development on and through

The key developers meet every week and their minutes are available from

Introducing a client library for 0-RTT converter


Contributors from Tessares: Grégory Vander Schueren, Gregory Detal & Olivier Bonaventure


0-RTT Converter is a MPTCP deployment option created by Tessares. It has been implemented for five telecom operators to deliver higher broadband speeds for remote residential customers. Hence, the first devices that embed 0-RTT Converter client are residential CPEs from several vendors.

In order to unlock new opportunities to improve Internet experience elsewhere than houses, our team has released a client library allowing other Linux-based connected devices to interact with the Transport Converter (the backend side).

As MPTCP has been selected by 3GPP to be the protocol for ATSSS service in emerging 5G architecture, this library could enable the User Equipment (Name given by 3GPP for the client side) to seamlessly switch between 3GPP networks (4G/5G) and unlicensed networks such as Wi-Fi. It could also select the access network with the lowest latency to send / receive data packets.

Click the link below to download the library. This is a work in progress and code contributions are more than welcome :

UPDATE July 2019 :

You can also find a Wireshark dissector plugin for the 0-RTT TCP Convert Internet draft at Again, this is a work in progress and code contributions are more than welcome.