This part of ISO 11519 specifies the data link layer and the physical layer of the Vehicle Area Network (VAN), communications network up to 125 kbit/s, for road vehicle application. The VAN is an access-method-oriented multimaster-multislave which allows optimized request/response management by special method of handling a remote transmission request (retaining access to the medium to allow insertion of a response). This part of ISO 11519 defines the general architecture of the low-speed communication network up 125 kbits/s and the content of the data link layer, and the physical layer for transmission between different types of electronic modules on board road vehicles.