Glossary

O

OPC
Originally, OLE for Process Control. A process control communications standard for accessing process data from multi-vendor systems.

Open system authentication
The IEEE 802.11 protocol specifies "open system authentication"" for wireless LANs that do not require any level of security. When using open system authentication to establish a communication link, the initiating station sends a randomly generated key that will be used for subsequent communications. The receiving station can accept or reject the initiating party's request. 

OSI
Open Systems Interconnection. A seven-layer reference model for networks, developed by the International Organization for Standardization (ISO). The OSI reference model is a formal method for describing the interlocking sets of networking hardware and software used to deliver network services. It is a good model, but strict compliance to the model is seldom accomplished.

OUI
Organizationally Unique Identifier. A 24-bit value assigned to an organization by the IEEE. Ethernet vendors use the 24-bit OUI they receive from the IEEE in the process of creating unique 48-bit Ethernet addresses. Contemporary Controls has been assigned a vendor OUI.