OpenVPN Data Channel Offload: Unleashing Superior VPN Performance
OpenVPN Data Channel Offload (DCO) is a Linux kernel module that significantly improves VPN performance by moving data channel processing from user space into the kernel. By reducing context switching and leveraging kernel-level networking and multi-threading, DCO enables:
Higher throughput.
Lower latency.
More efficient CPU usage.
Enhancing Access Server
With OpenVPN DCO, Access Server can deliver improved performance by offloading data plane operations to the Linux kernel. This reduces overhead from kernel-to-user space transitions and allows the system to handle VPN traffic more efficiently.
DCO in Access Server 3.x
In Access Server 3.x, DCO is enabled by default.
The installation script automatically installs and configures DCO.
When using a package manager, the DCO module may still need to be installed manually.
Access Server 3.2.0 introduces an updated DCO implementation based on upstream Linux kernel 6.16+.
These changes improve compatibility with modern Linux kernels and align DCO with upstream OpenVPN development.
Explore More
OpenVPN DCO In-Depth — Technical details and architecture
Turn On OpenVPN DCO — Configure and enable DCO.
Upgrade the OpenVPN DCO module — Keep your DCO module up to date.
ovpn-dco — OpenVPN DCO GitHub repository.