Network Classification by Functional Relationships

Networks can also be classified according to their respective functions and structure hierarchy. The classification that forms hence is:

Networks Classified by Functional Relationship

1. Client-Server Networks
2. Peer-to-Peer Networks

Also, we'll be studying the salient features of the Multi-tier Architecture of Client-Server Networks which I'm sure is very interesting.

So let's get started!

Client-Server Networks

Client-Server Networks are those in which certain computers have special dedicated tasks, hence providing services to other computers (in the network). The client–server model of computing is a distributed application structure that partitions tasks or workloads between the providers of a resource or service, called servers, and service requesters, called clients. A server host runs one or more server programs which share their resources with clients. A client does not share any of its resources, but requests a server's content or service function. Clients therefore initiate communication sessions with servers which await incoming requests. Examples of computer applications that use the client–server model are Email, network printing, and the World Wide Web.

Client-Server Network Model; Image Courtesy teleactivities.com

Multi-tier Architecture (often referred to as n-tier architecture) is a client–server architecture model in which presentation, application processing, and data management functions are physically separated. The most widespread use of multi-tier architecture is the three-tier architecture. It can be better understood using the following diagram:

The Three-tier implementation of Multi-tier architecture in Client-Server Network Models; Image Courtesy wikipedia.org

N-tier application architecture provides a model by which developers can create flexible and reusable applications. By segregating an application into tiers, developers acquire the option of modifying or adding a specific layer, instead of reworking the entire application.

A Three-tier architecture is typically composed of 

1. Presentation tier
2. Domain logic tier
3. Data storage tier

Peer-to-Peer (P2P) Network

Surely you would have used the torrents for free and convenient downloads. Perhaps even for downloading files that carry a copyright with them. Without even knowing, you may be one of the millions on the planet who supports this liberal (subjective) model of Internet by "seeding" and "leeching" an amazing number of torrents around the globe. Do you want to know what's the type of Network that supports your downloads??? If you do want to, then get ready to be amazed by the technology behind it as I carefully explain it below!

A Peer-to-Peer (P2P) Network is a type of decentralized and distributed network architecture in which individual nodes in the network (called "peers") act as both suppliers and consumers of resources, in contrast to centralized client–server model where client nodes request access to resources provided by central servers. In other words, Networks in which all computers have equal status are called peer-to-peer or P2P networks. In a peer-to-peer network, tasks (such as searching for files or streaming audio/video) are shared amongst multiple interconnected peers who each make a portion of their resources (such as processing power, disk storage or network bandwidth) directly available to other network participants, without the need for centralized coordination by servers.

And this is exactly the very quality of P2P Networks that makes them immune more or less from a law enforcing authority, because they don’t run from a single server and instead have millions of servers, exactly as many servers as the users on that network with that file serving to requests for that file from other peers.

A simple P2P Network Demonstration; Image Courtesy wikipedia.org

And that'd be all for now. Meet you in the next post with Network Classification on the basis of Network Topology. Meanwhile, I'd advise you to read our general article on Computer Network Classification and use it as a launchpad for gaining knowledge about other classifications.

Have a good day!