O-P

One-part flowspec

A flow specification that describes flows that have only best-effort requirements. Also known as a unitary flowspec.

Operational suitability

A measure of how well our network design can be configured, monitored, and adjusted by the customer's operators.

OSPF

An IGP that is based on a link-state algorithm.

Out-of-band management

When different paths are provided for network management data flows and user traffic flows.

Packet filtering

A mechanism in network elements to explicitly deny or pass packets at strategic points within the network.

Peers

Users, applications, devices, networks, or ASs that act at the same level in their hierarchy. For example, in a hierarchical client-server model, servers that act at the same level (e.g., directly above their clients) are considered peers. ASs that form a peering arrangement (using BGP4 and policies) are considered peers.

Peer-to-peer architectural model

Based on the peer-to-peer flow model, the important characteristics of this model are that there are no obvious locations for architectural features; functions, features, and services toward the edge of the network, close to users and their devices; and flows are end-to-end between users and their devices.

Peer-to-peer flow model

A flow model in which the users and applications are fairly consistent throughout the network in their flow behaviors.

Performance

The set of levels for capacity, delay, and reliability in a network.

Per-link and per-element (network element) characteristics

Characteristics that are specific to the type of element or connection between elements being monitored.

Physical security

The protection of devices from physical access, damage, and theft.

Planned hierarchy

Integrating into the network design methods to isolate and hide networks and their traffic from one another.

Policies

(1) Sets (formal or informal) of high-level statements about how network resources are to be allocated among users. (2) High-level statements about relationships between networks or ASs, as with peering arrangements. A policy may take an action (e.g., drop, accept, modify) on traffic that matches one or more AS parameters (e.g., AS number or list of AS numbers and metrics).

Polling

Actively probing the network and network elements for management data.

Polling interval

Time period between polls.

See also Polling.

Primary storage

Storage locations where data are staged for short periods (e.g., hours).

Privacy

A requirement to protect the sanctity of user, application, device, and network information.

Private IP addresses

IP addresses that cannot be advertised and forwarded by network elements and devices in the public domain (i.e., the Internet).

Public IP addresses

IP addresses that can be advertised and forwarded by network elements and devices in the public domain (i.e., the Internet).

Public key infrastructure

A security infrastructure that combines security mechanisms, policies, and directives into a system that is targeted for use across unsecured public networks (e.g., the Internet), where information is encrypted through the use of a public and a private cryptographic key pair that is obtained and shared through a trusted authority.