Author Login


Submit Article

Submit Article


Archive for April 2011

Network Types

Written by: Cresencio Daffon Jr. | 18 Apr, 2011
Network categories

Various types of personal networks are known according to their specific dimension that involves machines installed and utilized, bandwidth, and coverage. Networks that are private are usually those networks that belong to a group of companies.

These networks are categorized into three, namely:

Wide Area Network

Metropolitan Area Network

Local Area Network

Other network categories

There are other two network categories, such as:

1. Campus Area Networks Ė similar to Metropolitan Area Network but it has limited data transfer speed between the Local Area Network of each individual network

2. Tiny Area Network Ė with smaller coverage of connectivity about two to three devices compared to Local Area Network

Wide Area Network

Over great distances of geographical locations, the extended network or Wide Area Network is able to perform connectivity links between several Local Area Networks. With respect to the connections cost boosting along with range and may be lower, the Wide Area Network speed may vary. The Wide Area Networks run making use of routers that may select the best path with regards to the information for a network node to be reached. Probably the widely-known Wide Area Network would be the Internet.

Metropolitan Area Network

The connectivity between various physically near Local Area Networks together at high speeds with only an area of about estimated kilometers of a few dozen. Therefore, a Metropolitan Area Network enables two distant links connection as if these are located on the same Local Area Network.

A Metropolitan Area Network is created out of modems or switches linked to the other party together with fiber optic cables or high-velocity connectivity links.

Local Area Network

Local Area Network is a group of computer systems which all belong to the same organization and that are interconnected in just a small geographical location where a single network is being utilized, and most of the » Continue.. |

Basics of Managing Networks for Security, Fault, and Accounting

Written by: Cresencio Daffon Jr. | 16 Apr, 2011

The resources of network control access is the security managementís goal based on guidelines locally so that the unintentional or intentional sabotaging of network will not pushed through and without the right authorization the access on sensitive data is not possible. Access refusal for those who entered access codes that are not correct and monitoring of the users network resource logging on are the functions performed by the subsystem of the security management.

The subsystems of management for security are done through network resources partitioning into areas for unauthorized and authorized. Some users who are strangers in the company do not have any rights to access any resource of the network and it is also inappropriate to have information access from a specific department as for other users of network internally.

There are several functions performed by the subsystems of the security management because it determines the mapping between set of users and the resources of sensitive network as well as other entities, files, and systems for the identification of resources of sensitive network. Likewise, resources of sensitive network inappropriate access logging and resources of sensitive network points of access are also being monitored.


For an effective network operation, the fault managementís main goal is to fix, log, detect, and user notification of problems in network. The elements of management that the network of ISO implements all throughout is the management of fault because it can cause unlikely degradation of the network or frequent downtime error.

The problem isolation and symptoms determination are the things involved in fault management. On subsystems that are generally important, there is a tested solution as the problem is solved, and then there is a recording of the problem resolution and detection.


For the appropriate regulation of group or individual users on the » Continue.. |

CCNA Metrics of Routing

Written by: Cresencio Daffon Jr. | 15 Apr, 2011
For selecting the best route, software for switching is the one used wherein its information comes from tables for routing. We will focus our discussion on how the tables for routing is created, the particular information nature they have, and the use of algorithms for routing to know if a route is preferred over another.

For knowing the best route, there are various metrics used by algorithms of routing. The multiple metrics is the one used for basing the selection of route that is combined in one hybrid metric through algorithms of routing that are of high regard. The metrics such as cost of communication, bandwidth, load, reliability, delay, and length of path is used.

The metric for routing that is widely used is the length of path. The administrators of network are allowed by some protocols for routing to designate costs of arbitrary to an individual link of network. The associated costs total is the length of path with each link that passes through on this situation. The hop count is defined by different protocols of routing; the number of internetworking products like routers that must be taken on the way to a destination from a source that traversed is specified by this metric.

The algorithms of routing context, reliability is described in the rate of bit-error terms of the link of each link of network that is referred to as dependability. It is more usual than others that some link of network have tendency to go down. Some links of network have the possibility to be fixed faster or easier compared to different links after the failure of a network. In the reliability ratings designation, any factors of reliability can be taken accountable which through administrators of network, the values of numeric arbitrary is most of the time designated » Continue.. |

Bridges and Switches

Written by: Cresencio Daffon Jr. | 15 Apr, 2011
From the link layer comes bridging and switching controlling the flow of data, error transmission handling, opposing logical in favor of addressing physicality, and physical medium access management. The algorithms of accessing the media, handling error, control of the flow, and addressing is primarily the focus of protocols with multiple link layers as these functions as provided by bridges. The Fiber Distributed Data Interface, Token Ring, and Ethernet are examples of protocols of link layer that are widely used.

Keep in mind it is not true that devices like switches and bridges are complicated because the frames are forwarded to its destination, based on the frames information the decisions are forwarded, and frames incoming are analyzed. For instance, each frame has the whole path to the destination like the bridging of source and route. On the other hand, a move toward the destination makes the frames forwarded in situations wherein the bridging is transparent. Both switching and bridging main advantage is the transparent protocol of the upper layer wherein its information testing is not a requirement due to the fact that at the layer link these devices perform its operations. It only comes to say that the protocol of any layer of network can represent fast traffic forwarding. The traffic of networks such as Xerox Network Systems, Internet Protocol/Transmission Control Protocol, Apple Talk, and DECnet is common for a bridge to move.

The fields of Layer 2 is where the frames filtering of bridges is based, like for instance, instead of forwarding, rejection is programmed for a bridge to do for frames generally specific from a network. There are parameters used for bridges filtering task due to the reason that the information of the link layer usually includes the upper-layer protocol reference. For dealing with multicast packets and broadcast that are » Continue.. |

About Wide Area Network

Written by: Cresencio Daffon Jr. | 15 Apr, 2011
Between devices of two networks within a network shared is where you can create a logical circuit called a virtual circuit which is classified into two categories, permanent and switched.

Data transfer is one mode composing a virtual circuit that is established permanently and this is used in constant transfer of data between devices. The bandwidth use linked with the virtual circuit creation and stoppage is lowered with virtual circuit permanent category, but because of the continuous availability of the virtual circuit, the price goes higher. For service purposes, when placing an order, the service provider configures the virtual circuit permanent category in general.

While on the other hand, when transmission is done, virtual circuits that is created on demand and is stopped, itís called virtual circuitís switched category. There are three phases of communication for virtual circuitís switched category, namely: termination of circuit, establishment of circuit, and transfer of data. The creation of virtual circuit between devices of destination and the source are the things involved in the phases of establishment. The data transmission between the devices over the virtual circuit is what is involved in transferring of data, and the tearing down of virtual circuit between devices of destination and the source is what is involved in the stoppage phase of the circuit. Whenever there is a sporadic transfer of data between devices, you may rely on what the switched virtual circuit can do because it can make the bandwidth higher to use for creating circuit and the phases of stoppage, but with the continuous availability of virtual circuit, the price becomes lower.

On the other hand, for Wide Area Network connectivity, there are techniques that the dialup services offered which are cost-effective. The dial backup and Dial-on-Demand Routing are two implementations of dialup that are widely-known.

When sending » Continue.. |

CCNA Methods of Accessing the Media of Local Area Network

Written by: Cresencio Daffon Jr. | 14 Apr, 2011
When two or more devices of network have to send data at the same time, contention of media is present. Some method type must be used for letting one device access at a time for the network media because simultaneous network communication on various devices is not possible; and it is done by passing the token and through collision detect/carrier sense multiple access, which are the two primary ways available.

Take note that the network media is the one being contended by devices for network in Ethernet which is a technology involving the use of collision detect / carrier sense multiple access, the one used by networks. The device listens first to check if the network is being used by another device when sending data is needed to be done and if the network is not in use, data sending begins.

For the device to see if there is another occurrence of a collision, it then again performs another listening task after transmission is done. When simultaneous sending of data by two devices occurs, there is a collision. Before the device sends its data again, a time with random length is awaited by an individual device as soon as a collision takes place. Take note that between two devices, a collision will not happen like in most instances.

There will be more collision to happen as the network becomes busier due to this contention type of network. As soon as the network devices increase, there is a fast degrading of the Ethernetís performance. The token, frame of the network that is specially created, is passed from device to device within the network in the likes of Fiber Distributed Data Interface and Token Ring. Before sending a data, the device has to wait until the token is obtained.

For a network media » Continue.. |

History, Basics, and Challenges of Internetworking Technologies for CCNA

Written by: Cresencio Daffon Jr. | 13 Apr, 2011
Internetworking Technologies History

Based on the information gathered, attached terminals and mainframes used made up time-sharing networks which are said to be as the first networks. Both the architecture of Digital network and Systems Network Architecture (SNA) of International Business Machines (IBM) had implemented these network facilities.

With the revolution of personal computers, the LANs or Local Area Networks have changed dramatically. The emerging need for messaging, files exchange, printers, and file servers has been the main purpose of Local Area Network for binding a lot of users even within a small geographical location.

On the other hand, for making it possible to connect people from distant locations, Local Area Network was certainly not enough. From there arise the relatively useful system of WANs or Wide Area Network. For Local Area Networks connection, the technologies used are in the likes of radio links, ADSL, Frame Relay, and Automated Teller Machine. Take note that on a daily basis, there arise a number of latest methods for the connection of Local Area Network that are scattered.

Presently, there is a wide use of internetworks that are switched and Local Area Networks that are of high-speed for supporting application that have high-bandwidth such as videoconferencing and multimedia messaging or functions and because they primarily operate at an extremely high speed connectivity.

Internetworking Technologies Basics

We are going to discuss terms and concepts that are fundamental to address the internetworking language that is ever changing and continuously updating to come along with changes in the world of Information Technology. Before we go any further, let us talk about what Internetworking is.

When we say internetwork, it is referred to the procedures, products, and industry used for meeting the obstacles of internetworking creation and administration. Basically speaking, when you say internetwork, this is one large network that function for » Continue.. |

© 2011