On October 21, 2025, a non-mandatory upgrade to version 11.6.0 will allow interested Session Node Operators to participate in internal testing of Session Router, a faster onion routing protocol based on an extensively rewritten version of Lokinet.
Following this testing period, a mandatory node upgrade will be released that requires all operators to run Session Router, followed by a hardfork.
What is Session Router?
Session Router is an onion routing network that is optimized for secure, low latency network communication. Session Router is the result of an extensive top-to-bottom rewrite of Lokinet, which Session Nodes already run at present.
By completing this voluntary upgrade, node operators will be able to test, share feedback and report any bugs found while running Session Router. This testing period will support an upcoming mandatory upgrade and hardfork, after which it will be a requirement for all operators to run Session Router.
Following the mandatory upgrade, an upcoming version of Session messenger for iOS (with other platforms to follow) will be released that allows users to opt in to using Session Router for all communications. This should improve performance and reliability for Session. The biggest improvements for Session users will likely be experienced as faster message sending and delivery as well as faster media uploading and downloading.
Following the iOS release, the ability to opt in to Session Router will be rolled out to Android and Desktop clients, and in future, Session Router will ultimately become the default networking layer for the Session app.
As this first release does not fully support all of the current Lokinet version’s capabilities (exit traffic and non-Linux full client support is still being worked on), and is not compatible with the existing versions of Lokinet, Session Router will run alongside the current version of Lokinet while remaining capabilities are finalized. The transition to Session Router and away from the current Lokinet network is expected to be completed over the next few months.
In the future, Session Router will enable new features for Session, such as larger attachment sizes and, on a longer time horizon, onion-routed voice and video calls. This is because Session Router is faster and can onion route a broader range of network protocols than Session’s current onion-routing protocol, which is limited in the sizes of files it can transfer between users, and currently is unable to support high quality voice and video calls.
How to Complete This Upgrade
Once the upgrade is released on October 21, 2025, please follow these steps if you would like to participate in testing Session Router:
- First, sync your repositories:
sudo apt update
- Then install updates using:
sudo apt upgrade
Thank you in advance for your cooperation!