QNX 6.5 used the io-net manager. The documentation covers a custom "L4" stack. Modern TCP tuning parameters do not exist. The ifconfig output is also different.
This guide provides a comprehensive overview of the QNX 6.5 documentation structure, key components, and how to find the technical details you need. 🧭 The Core Documentation Hierarchy qnx 6.5 documentation
When searching the documentation, ensure you are not looking at QNX 6.6 or 7.0 manuals. While the microkernel philosophy is similar, there are significant changes in header file locations and toolchain support (GCC versions) between 6.5 and later iterations. qnx 6.5 documentation