Network architecture defines the building blocks of a network as phys.pdf
- 1. Network architecture defines the building blocks of a network as physical or functional entities. Give examples of physical and functional entities that you would use as building blocks for a network. How docs each approach (physical and functional) differ? A network's architecture differs from its design, in terms of its scope, level of detail, description, and location information. Describe how an architecture and design differ in each characteristic. Give examples of external relationships between each of the following component architectures: addressing routing, network management, performance, and security. What are the differences between the LAN/MAN/WAN and Access/Distribution/Core architectural models? Under what conditions might each be applied to a network? Solution A network element is usually defined as a manageable logical entity uniting one or more physical devices. This allows distributed devices to be managed in a unified way using one management system. A network manager discovery returns many different types of entity ->Physical and logical entities, including devices and their physical and logical characteristics, such as slots, cards, ports, and interfaces, and the relationships between them. ->Protocol end points represent protocol or technology-specific information that is typically associated with an entity representing a port or interface resource. ->Device collections, including MPLS VPNs, global VLANs and subnets. ->Hosted services, including BGP and OSPF services hosted on a device. Clouds are used to represent networks external to the one pictured for the purposes of depicting connections between internal and external devices, without indicating the specifics of the outside network. For e.g., in the hypothetical local area network pictured to the right, three personal computers and a server are connected to a switch, the server is further connected to a printer and a gateway router, which is connected via a WAN link to the Internet. At different scales diagrams may represent various levels of network granularity. At the LAN level, individual nodes may represent individual physical devices, such as hubs or file servers, while at the WAN level, individual nodes may represent entire cities. In addition, when the scope of a diagram crosses the common LAN/MAN/WAN boundaries, representative hypothetical devices may be depicted instead of showing all actually existing nodes. For e.g., if a network appliance is intended to be connected
- 2. through the Internet to many end-user mobile devices, only a single such device may be depicted for the purposes of showing the general relationship between the appliance and any such device. Computer network analysis, the architecture, and design have traditionally focused on capacity planning, which is the bandwidth required in the network to accommodate most short- and long-term traffic fluctuations. Network analysis helps us understand what problems we are trying to solve, and in the process, we compile information that will be used in developing an architecture and design. Computer network architecture uses this information to develop a high-level, end-to-end structure for the network. A network architecture develops the major network functions for addressing/routing, network management, performance, security as architectural components that will be brought together to form the network goals for the architecture and sets of interactions, trade-offs, dependencies, and constraints that will be used to optimize the architecture.