<networking> A device or program to translate between different protocols which serve similar functions (e.g. TCP and TP4). Some call this a "gateway", though others use that term for other kinds of internetworking device. (1996-03-07)

A protocol converter is a device used to convert standard or proprietary protocol of one device to the protocol suitable for the other device or tools to achieve the desired interoperability. Protocols are software installed on the routers, which convert the data formats, data rate and protocols of one network into the protocols of the network in which data is navigating.

In natural and social science research, a protocol is most commonly a predefined procedural method in the design and implementation of an experiment. Protocols are written whenever it is desirable to standardize a laboratory method to ensure successful replication of results by others in the same laboratory or by other laboratories.

In international politics, protocol is the etiquette of diplomacy and [of state]. It may also refer to an international agreement that supplements or amends a treaty.

A communication protocol is a system of rules that allows two or more entities of a communications system to transmit information via any kind of variation of a physical quantity. The protocol defines the rules, syntax, semantics and synchronization of communication and possible error recovery methods.

A security protocol (cryptographic protocol or encryption protocol) is an abstract or concrete protocol that performs a security-related function and applies cryptographic methods, often as sequences of cryptographic primitives. A protocol describes how the algorithms should be used and includes details about data structures and representations, at which point it can be used to implement multiple, interoperable versions of a program.

<networking> The software and/or hardware environment of two or more communications devices or computers in which a particular network protocol operates. A network connection may be thought of as a set of more or less independent protocols, each in a different layer or level. The lowest layer governs direct host-to-host communication between the hardware at different hosts; the highest consists of user application programs. Each layer uses the layer beneath it and provides a service for the layer above. Each networking component hardware or software on one host uses protocols appropriate to its layer to communicate with the corresponding component (its "peer") on another host. Such layered protocols are sometimes known as peer-to-peer protocols. The advantages of layered protocols is that the methods of passing information from one layer to another are specified clearly as part of the protocol suite, and changes within a protocol layer are prevented from affecting the other layers. This greatly simplifies the task of designing and maintaining communication systems. Examples of layered protocols are TCP/IP's five layer protocol stack and the OSI seven layer model. (1997-05-05)

The Simple Sensor Interface (SSI) protocol is a simple communications protocol designed for data transfer between computers or user terminals and smart sensors. The SSI protocol is an Application layer protocol as in the OSI model.

In telecommunications, a proprietary protocol is a communications protocol owned by a single organization or individual.Proprietary protocol Definition — PC Magazine Encyclopedia

AAA refers to Authentication (to identify), Authorization (to give permission) and Accounting (to log an audit trail).