Network Architecture Components
Los componentes de la arquitectura son una descripción de cómo y dónde cada función de una red se aplica dentro de esa red. Se compone de un conjunto de mecanismos (hardware y software) cada cual con una función que se aplica a la red, y un conjunto de relaciones internas entre estos mecanismos.
Cada función de una red representa una capacidad importante de esa red. Las cuatro funciones más importantes para medir las capacidades de las redes son:.
Otras funciones generales que también podrían ser desarrolladas como componentes de arquitecturas son la infraestructura y almacenamiento. Existen mecanismos de hardware y software que ayudan a una red a lograr cada capacidad. Las relaciones internas consisten en interacciones (trade- offs, dependencias y limitaciones), protocolos y mensajes entre los mecanismos que se utilizan para optimizar cada función dentro de la red. Las compensaciones son los puntos de decisión en el desarrollo de cada componente de la arquitectura. Se utilizan para priorizar y decidir qué mecanismos se han de aplicar. Las dependencias se producen cuando un mecanismo se basa en otro mecanismo para su funcionamiento. Estas características de la relación ayudan a describir los comportamientos de los mecanismos dentro de una arquitectura de componentes, así como el comportamiento global de la función en sí.
El desarrollo de los componentes de una arquitectura consiste en determinar los mecanismos que conforman cada componente, el funcionamiento de cada mecanismo, así como la forma en que cada componente funciona como un todo. Por ejemplo, considerando algunos de los mecanismos para el rendimiento de calidad de servicio (QoS), acuerdos de nivel de servicio (SLA) y políticas. Con el fin de determinar cómo el rendimiento de trabajo para una red, se necesitan determinar cómo funciona cada mecanismo, y cómo funcionan en conjunto para proporcionar un rendimiento de la red y del sistema.
Las compensaciones son los puntos de decisión en el desarrollo de cada componente. A menudo hay varias compensaciones dentro de un componente, y gran parte de la refinación de la arquitectura de red ocurre aquí.
Las dependencias son los requisitos que describen como un mecanismo depende en uno o más de otros mecanismos para poder funcionar. La determinación de tales dependencias ayuda a decidir si las compensaciones son aceptables o inaceptables.
Las restricciones son un conjunto de limitaciones dentro de cada componente de arquitectura. Tales restricciones son útiles en la determinación de los límites en que cada componente opera.
Addressing/Routing
Addressing involves applying identifiers (addresses) to devices at different protocol layers (for example, data link and network), while routing focuses on learning about connectivity within and between networks and applying this IP connectivity information to forward packets to their destinations.[6].
Addressing/routing describes how user and management traffic flows are sent across the network, as well as the hierarchy, separation, and grouping of users and devices.
This architectural component is important as it determines the shape of the user and how management traffic flows propagate throughout the network. This is closely tied to network management architecture (for management flows architecture) and performance (for user flows). This component also helps determine the degrees of hierarchy and diversity in the network, and how areas of the network are subdivided.
From an addressing perspective, mechanisms can include subnets, variable-length subnets, supernets, dynamic addressing, private addressing, virtual LANs (VLANs), IPv6, and network address translation (NAT).
From a routing perspective, mechanisms include switching and routing, default route propagation, classless inter-domain routing (CIDR), multicast, mobile IP, route filtering, peering, routing policies, confederations and IGPs, and EGP selection and placement.
Network management
Network management consists of functions to control, plan, allocate, implement, coordinate monitor network resources. Network management is part of most or all network devices. As such, the network management architecture is
important as it determines how and where management mechanisms are applied in the network. Es probable que los otros componentes de la arquitectura (por ejemplo, seguridad de TI) requieran un cierto grado de control y de gestión y además interactúen con la gestión de la red.
This component describes how the system, including the other network functions, is controlled and managed. It consists of an information model that describes the types of data that are used to control and manage each of the elements in the system, the mechanisms for connecting devices in order to access data, and the management data flows across the network. Network management mechanisms include data monitoring and collection: instrumentation to access, transmit, act on, and modify data.
Network management includes the following mechanisms:
Performance
Performance consists of the set of mechanisms used to configure, operate, manage, and account for resources on the network that distribute performance to users, applications, and devices.
This includes traffic planning and engineering capabilities, as well as a variety of service mechanisms. Performance can be applied at any of the protocol layers, and is often applied across multiple layers. Therefore, there may be mechanisms aimed at the network, physical or data link layer, as well as the transport layer and above.
Performance describes how network resources are allocated to user traffic flows and management. This involves prioritizing, scheduling, and conditioning traffic flows within the network, either end-to-end between source and destination for each flow, or between network devices on a peer-to-peer basis. It also consists of mechanisms to correlate users, applications and device requirements to traffic flows, as well as traffic engineering, access control, quality of service, policies and service level agreements (SLAs).
Quality of service, or QoS, consists of determining, creating, and knowing how to act on priority levels for traffic flows.[7] Resource control refers to mechanisms used to allocate, control, and manage network resources for traffic. Service level agreements (SLAs) are formal contracts between the provider and the user that define the terms of the provider's responsibility to the user and the type and extent of accountability if those responsibilities are not met.
This architectural component is important as it provides the mechanisms for controlling network resources assigned to users, applications, and devices. This can be as simple as determining the amount of capacity available in various regions of the network, or as complex as determining capacity, delay, and RMA characteristics on a flow basis.
Security is a requirement to ensure the confidentiality, integrity and availability of user, application, device and network information and physical resources.[8] This is often combined with privacy, which is a requirement to protect the privacy of the user, application, device and network information. Security describes how system resources are protected from theft, damage, denial of service (DOS), or unauthorized access. Security mechanisms are implemented in security regions or zones, where each security region or zone represents a certain level of sensitivity and access control.
There are various security mechanisms, some of them are listed below:
Optimization
Optimization consists of determining and understanding the set of internal relationships between the components of the architecture to be optimized for a particular network. This is based on the input for that particular network, the requirements, the estimated traffic flows, and the goals for that network. The needs of users, applications and devices often affect the level of performance, security and network management requirements. Such requirements are directly related to the selection and placement of mechanisms within an architectural component.
By understanding the types of flows in the network, each component of the architecture can be developed to focus on different mechanisms that optimally support high priority flows.
Goals for a network architecture are derived from requirements, determined from discussions with users, management and staff, or can be taken as an extension of the scope and scale of the existing network. When objectives are developed from a variety of sources, they provide broad insight into which functions are most important in a network.