Lessons learned in software implementation of ARINC 664 protocol stack in Linux

The ARINC 664 is a deterministic avionics data network based on commercial 10/100Mbit switched Ethernet which provides deterministic timing and redundancy management, secure and reliable communications of critical data by specific means. For many aircraft program world wide ARINC664 is the preferred choice for data network due to its deterministic nature. Due to the closed community usage the COTS ARINC664 modules are expensive. To simulate the aircraft data network behavior many nodes are required to communicate and analyse with each other. An attempt is made here to develop ground based ARINC664 nodes with open source Linux and low cost Ethernet cards for avionics applications. A low level socket end point communication is provided by means of packet socket domain, using these techniques, algorithms are developed and an ARINC 664 software protocol stack for transmission and reception of ARINC 664 messages in Linux is designed and implemented in a vanilla Linux operating system. The algorithms and semantics of protocol implementation in Linux and techniques to create VL's using configuration(re)tables are established, the stack's conformity to the temporal restrictions and protocol requirements of ARINC 664 as defined in ARINC 664-7 are analysed and limitations are recognised. The soft ARINC 664 implementation in Linux is extensively tested between two Linux personal computers and between a PC and a certified ARINC 664 end system.