Computer networks hierarchy

What is a hierarchy network?
A hierarchical network is defined as a treelike converging system with multiple inflow points (sources) and one outlet (sink).
Figure 18.13 illustrates two hierarchical networks.
Flow directions in this type of network are known.
Fluid flow in this type of network can be simulated using sequential solving approach..
What is hierarchy of network management?
In a Hierarchical model, the network is divided into distinct layers.
These layers (also known as Tiers) are connected with one another in the form of a hierarchy which enables the network to be divided into more manageable blocks and these blocks limit the local traffic to remain local even if it is broadcast traffic._{Nov 17, 2022}.
A hierarchical or extended star topology is a star network with an additional networking device connected to the main networking device.
Typically, a network cable connects to one switch, and then several other switches connect to the first switch.
It decreases the complexity of network topology, increases routing efficiency, and causes much less congestion because of fewer routing advertisements.
With hierarchical routing, only core routers connected to the backbone are aware of all routes.
Routers that lie within a LAN only know about routes in the LAN.
There are two hierarchical addressing systems on the Internet: domain names and IP addresses.
People use domain names (like snap.berkeley.edu) to visit websites.
Computers translate those domain names to IP addresses (like 128.32. 189.18) to locate and send data behind the scenes.

A hierarchical design separates a network into distinct layers, where each layer has a series of functions that define its role in the network. Because of this, a network designer can choose the optimal hardware, software, and features to take on a particular role for that network layer.

A protocol hierarchy in computer networks refers to the organization and arrangement of networking protocols in a layered structure. This layered approach helps in achieving interoperability, modularity, and ease of implementation and maintenance within complex network systems.

Introduction. A Protocol Hierarchy in a computer network is a set of rules and conventions that govern the communication between different devices and systems. These protocols are organised into layers, with each layer building upon the one below it to provide a set of services and functions.

In computer science, the method of contraction hierarchies is a speed-up technique for finding the shortest-path in a graph.
The most intuitive applications are car-navigation systems: a user wants to drive from mwe-math-element> to mwe-math-element> using the quickest possible route.
The metric optimized here is the travel time.
Intersections are represented by vertices, the road sections connecting them by edges.
The edge weights represent the time it takes to drive along this segment of the road.
A path from mwe-math-element> to mwe-math-element> is a sequence of edges ; the shortest path is the one with the minimal sum of edge weights among all possible paths.
The shortest path in a graph can be computed using Dijkstra's algorithm but, given that road networks consist of tens of millions of vertices, this is impractical.
Contraction hierarchies is a speed-up method optimized to exploit properties of graphs representing road networks.
The speed-up is achieved by creating shortcuts in a preprocessing phase which are then used during a shortest-path query to skip over unimportant vertices.
This is based on the observation that road networks are highly hierarchical.
Some intersections, for example highway junctions, are more important and higher up in the hierarchy than for example a junction leading into a dead end.
Shortcuts can be used to save the precomputed distance between two important junctions such that the algorithm doesn't have to consider the full path between these junctions at query time.
Contraction hierarchies do not know about which roads humans consider important, but they are provided with the graph as input and are able to assign importance to vertices using heuristics.

Computer networks hierarchy

What is a hierarchy network?

What is hierarchy of network management?