Difference between Logical & Physical Design of a Network
When we look at the differences between logical design and physical design of a network it is easy to think of it as the logical as the functional part and physical as the seeing it part. With that stated there is more to this than just the functional and seeing parts. In order to understand the differences from one to the other, we need more information. In the following paragraphs I will try to outline what makes up the differences between logical and physical design of a network.
So let's first look at what constitutes a logical design of a network. The first thing we know is that the logical design is, "The part of the design phase of the SDLC in which all functional features of the network chose for development are described independently of any computer platform." There are other ways to describe a logical network, but the one that comes to mind is how the network will be structured. Basically we are talking about all of the logical aspects of the network. According to Webopedia, "the logical topology is the way the data passes through the network from one device to the next without regard to physical interconnection of the devices."
Also the logical design lacks specific details such as technologies and standards and focuses on the general needs of the network. A logical design can be a view of any part of the network, whether it be the whole or just a part of it. Another element of the logical design is the IP addresses and their association with the different parts of the network. The IP addresses are assign to devices such as routers, switches, servers, workstations, and other devices that utilize the network. In the logical design we usually do not show the actual interfaces and physical cables in the diagrams; thus giving us the true meaning of the term "logical."
IP structure is a big part of the logical design of a network as well as security planning. A good logical design will have the foundation for security which provides the framework stages needed for security. Each layer should have scalable security services that involve the routers, switches, servers, workstations and other devices that are utilizing the network. In some cases the logical design is described using the terms of the customer's business. Processes, roles, and even locations can show up in the logical design; however, the important aspect of the logical design is that it is part of the requirement set for a solution to a customer's problem (Jim's Weblog, 2005).
Multiplexing will gather the data from the source host and give that data some header information. This data will be created into segments by demultiplexing and then be sent to the 3rd layer (Network layer). So to summarize multiplexing will gather data and give it header information and demultiplexing will create segments and sent them to the network layer. Now with flow control that will relate with multiplexing, mainly because it can take multiple data streams and combine them into one shared stream, making that a form of data flow control. Now as far as error checking that will relate to the frames of the data. The logical link control will use a frame check sequence (FCS) to check the frame to see if there is any problems with it. If it detects an error during the frame check sequence then the frame will be discarded and the data will be passed on to the network layer. With this all being said this will mainly be used in the OSI model since the logical link control is the sub-layer for the data link layer. (The other sub layer being MAC) Without the logical link control or 802.2 then the data link layer wouldn’t function
It just doesn't get much simpler than the physical bus topology when it comes to connecting nodes on a Local Area Network (LAN). The most common implementation of a linear bus topology is IEEE 802.3 Ethernet. All devices in a bus topology are connected to a single cable called the bus, backbone, or ether. The transmission medium has a physical beginning and an end. All connections must be terminated with a resistor to keep data transmissions from being mistaken as network traffic. The terminating resistor must match the impedance of the cable.
Devices are needed to create a network and to run it affectively. For example, some common devices:
ABSTRACT : This paper describes the basic threats to the network security and the basic issues of interest in designing a secure network. it describes the important aspects of network security. A secure network is one which is free of unauthorized entries and hackers. INTRODUCTION
The security configuration of such devices should be documented, reviewed, and approved by an organization change control board. Any deviations from the standard configuration or updates to the standard configuration should be documented and approved in a change control system. At network interconnection points, such as Internet gateways, inter- organization connections, and internal network segments with different security controls implement ingress and egress filtering to allow only those ports and protocols with an explicit and documented business need. All other ports and protocols should be blocked with default-deny rules by firewalls, network-based IPS, and/or routers. All new configuration rules beyond a baseline-hardened configuration that allow traffic to flow through network security devices, such as firewalls and network-based IPS, should be documented and recorded in a configuration management system, with a specific business reason for each change, a specific individual’s name responsible for that business need, and an expected duration of the need. Network filtering technologies employed between networks with different security levels (firewalls, network-based IPS tools, and routers with access controls lists) should be deployed with capabilities to filter Internet Protocol version 6 (IPv6) traffic. The
...vantage of the overall network design and implement usable subnets with virtual local area networks. Use encryption and encapsulation to secure communications of public segments to enable extranets and cross-Internet company traffic. Use items such as intrusion detection systems and firewalls to keep unauthorized users out and monitor activity. Taken together, these pieces can make a secure network that is efficient, manageable, and effective.
It has been demonstrated that a number of interoperable systems must be implemented to fully protect a network; a strategy known as Defense in Depth. Due to the multitude of security devices and device categories available, it can be very difficult to identify the correct tools for meeting security goals. Using the Defense in Depth strategy will require an understanding of the interactions between devices occuring within the network.
The logic used to explain miracles of everyday life, thinking logically helps man to question the functioning of everything around us, the logic used to argue and is somehow a thought an idea that influences us for an action we do in our daily lives.
The elements of design were created by Arthur Wesley Dow to help people see, describe, and create visual qualities in a systematic way. It consists of 7 elements: line, shape, form, colour, value, texture and space.
The protocol stack is built up with a few layers and planes, namely application layer, transport layer, network layer, data link layer, physical layer. And the planes are task management plane, mobility management plane and power management plane. The block diagram of a protocol stack is shown below
To sum it all up I think of the Logical Design as being the thinking part of the design, trying to be logical in the design. The Physical Design is all the hardware and types of systems used to connect it all together and make it all work.
There are several advantages to the layered approach provided by the OSI model. With the design separated into smaller logical pieces, network design problems can be easier to solve through divide and conquer techniques. Vendors who follow the model will produce equipment that is much more likely to be compatible with equipment from other vendors. The OSI model also provides for more extensible network designs. New protocols and other network services are more easier added to a layered architect.
A critical part of network planning involves setting up of security mechanisms. Deploying the network with security configuration provides superior visibility, continuous control and advanced threat protection across the extended network. Additionally, security procedures define policies to monitor the network for securing critical data, obtain visibility, mitigate threats, identify and correlate discrepancies.
The network management plan and security plan is important to help the company figure out how they will improve its network and security procedures for the company. Planning involves outlining objectiv...
It should not come as a big surprise that human thinking could be directed in more than one way when there are different ends in mind. Basically design thinking is primarily about the path, which is being distinguished from its more knowable way of thinking, which is scientific thinking. Simply because design thinking is focusing more on creating the artifacts of an evolving culture unlike scientific thinking’s path that leads toward the discovery of fundamental knowledge, a rigorous process of sifting experience into facts.