A Carrier Sense Multiple Access with Collision Detection (CSMA/CD) Local Area Network (LAN) provides high-speed communications channels for connecting computers and other digital devices located within a moderate-sized geographic area. Like other LANs, the CSMA/CD LAN falls between long-distance, low-speed networks that carry data for hundreds or thousands of kilometers, and specialized, very high-speed intercommunications that are generally limited to tens of meters. The CSMA/CD LAN is intended primarily for use in such areas as office automation, distributed data processing, terminal access, distributed systems and other situations requiring economical connection to a local communication medium carrying sporadic traffic at high-peak data rates. For Tru64 UNIX, the DNA CSMA/CD module incorporates the functions and operations defined in the Ethernet Specification V2.0 and the ISO 8802-3 (IEEE 802.3) CSMA/CD Access Method and Physical Layer specification as well as parts of the ISO 8802-1 (IEEE 802.1) Addressing, Internetworking, and Network Management and the ISO 8802-2 (IEEE 802.2) Logical Link Control specifications. To this the DNA CSMA-CD module adds features often needed by users of the Data Link. A typical such Data Link user is the Network Layer of the DNA.
1 – Subentities
The subentities below the CSMA-CD module are: Node___CSMA-CD____Port | |_Station The CSMA-CD entity is the top-level entity in the hierarchy of entities belonging to the CSMA-CD module. A CSMA-CD PORT entity represents an access point to the service offered by the CSMA-CD module. A client transmits and receives data through a port. Ports are created and deleted by client use of open and close service interface procedures. The port-name refers to the port managed by this command. A CSMA-CD STATION entity manages a CSMA/CD controller. Wherever Phase IV DECnet manages a line, DECnet-Plus manages a station. Each station corresponds to a particular logical link control (LLC), medium access control (MAC), and physical attachment. The station-name refers to the station managed by this command.