Reliability and bounded latency is critical for distributed real-time control networks such as CAN bus. We improved Linux kernel CAN subsystem and made its performance analysis for a big automotive OEM. We also work in the area of CAN bus security extensions. Furthermore, the area of our interests includes creation of efficient schedules for both deterministic time-triggered fieldbus protocols such as FlexRay and TTEthernet and nodes, connected by this fieldbus. Our Ethernet based publish-subscribe protocol implementation has been one of reference implementation to OMG DDSI-RTPS specification. We analyze latencies and resource allocation from as low level as PCIe transactions up to admission tests in communication middleware based on contemporary scheduling theory.