F-G

Features

Network functions and performance that are desired but are not necessary for the network to successfully support its users, applications, and devices.

Fine granularity

In the distributed-computing flow model, in which a task is sub-divided between several devices and the computing is done concurrently.

Firewalls

Combinations of one or more security mechanisms, implemented in devices or network elements (routers), which are placed at strategic locations within a network.

Flow analysis

The process of characterizing traffic flows for a network, where they are likely to occur, and what levels of performance they will require.

Flows

Sets of network traffic (application, protocol, and control information) that have some common attributes, such as source/destination address, information type, routing, or other end-to-end information. Flows also have directionality. Also known as traffic flows or data flows.

Flow-based architectural models

Models that take particular advantage of traffic flows from the flow specification.

Flow models

Groups of flows the exhibit specific, consistent behavior characteristics. Flow models are characterized primarily by their directionality, hierarchy, and interconnectivity.

Flow prioritization

Ranking flows based on their importance (e.g., number or users, applications, or devices supported).

Flow specification

A listing of the flows for a network, along with their performance requirements and priority levels (if any). Also known as a flowspec.

Flowspec

See Flow specification.

Flowspec algorithm

A mechanism to combine the performance requirements (capacity, delay, and reliability) for flows in such a way that describes the optimal composite performance for that flow or group of flows.

Function

A major capability of a network.

Functional architectural models

Models that focus on one or more functions or features planned for in the network.

Functional areas

Groups within the system that share a similar function. Groups may be of users (workgroups), applications, devices, or combinations of these, and they may share similar jobs/tasks, physical locations, or functions within the network (e.g., backbone routing).

General access

Common access of users to applications, computing, and storage resources across a network.

General-performance network

A network that does not have a distinctive set of applications, users, or hosts that would be the performance driver for that network.

General thresholds

Performance thresholds that apply to most or all networks.

Generic computing devices

Common desktop and laptop computers that most users have.

Guaranteed service

Network service that is predictable and reliable to such a degree that, when service is not available, the system is in some way held accountable.