At first, the IEEE 802.16e and IEEE 802.20 standards may appear to be very similar. Both standards were developed to specify an air interface for providing broadband access to mobile users. Both standards will have low latency and will utilize packet architecture. However, other than the resemblances of their aims, there are few other parallels.

First the 802.16e standard is an extension of an existing standard, IEEE 802.16a. IEEE 802.20 is an entirely new standard optimized for mobility. 802.16e uses extensions to the MAC and PHY layers from 802.16a, while 802.20 uses new MAC and PHY layer designs. The result of this is that 802.16e-based product will be available well before any 802.20 products are on the market.

Although there is an obvious parallel between the technologies used by both standards and the type of user they are aiming to serve, there is a primary difference between the two. IEEE 802.20 is designed for users traveling at speeds of up to 250Kmh (155 mph), whereas 802.16e is aimed at users traveling at vehicular speed. So someone who is walking and needs broadband access via their PDA or laptop could do so using 802.16e-based technology. On the other hand, a user traveling on a high-speed train would require an 802.20-based product to gain wireless broadband access. (more…)

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Introduction to building a security roadmap
Securing a system against attack is an important responsibility of a system administrator. As a system administrator, you can address this security issue by creating a roadmap that outlines your plans for the system’s security requirements. This roadmap details what information is required to allow you to attain your goal. Each roadmap is designed to meet the specific security requirements of an organization. The roadmap is the blueprint used to ensure a system is adequately secured.

Developing the roadmap
Before a roadmap can be defined, you need to decide what issues it needs to address. This can be determined by examining the policies that senior management have approved and brought into practice. These can include organizational policies such as:

• personnel and physical security
• protection of corporate assets and information
• how employees are hired and their employment terminated
• the responsibilities of employees

You should also consider the security principles behind the system’s design, and how to comply with them. This is generally referred to as the system architecture. (more…)

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Overview of FIFO and WFQ
First-in-first-out (FIFO) and weighted fair queuing (WFQ) are the two primary default queuing mechanisms that are implemented on Cisco routers. Despite a number of drawbacks, FIFO is the most-used queuing mechanism and it is supported in all versions of Cisco IOS. WFQ, which dynamically divides available bandwidth by a calculation based on the total number of flows and the weight of each given flow, was developed to resolve some of the problems resulting from the use of basic queuing methods, including FIFO, such as queue starvation, delay, and jitter.

The FIFO queuing mechanism
FIFO queuing has no classification because all packets belong to the same class. Packets are dropped when the output queue is full – this process is known as tail dropping. The scheduler services packets in the order in which they arrive. The software FIFO queue is basically an extension of the hardware FIFO queue. (more…)

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Do you aware how many ATM standards bodies?

Four main standards bodies are associated with ATM standards. The international bodies are the Asynchronous Transfer Mode (ATM) Forum and the United Nations agency, the International Telecommunications Union, Telecommunications Standardization Sector (ITU-T). The regional bodies are the American National Standards Institute (ANSI) and the European Telecommunications Standards Institute (ETSI).

The ATM forum leads the way in developing and rolling out ATM standards. A group of manufacturers created this forum to ensure the rapid progress of the ATM standardization process, and it wanted to advertise ATM capability. This group is also active in drawing up solutions for the problems and challenges generated in ATM application.

International bodies

The ATM forum is divided into the

• Technical Committee, This committee comprises principal members of the forum, and it is responsible for the development of technical standards.
• Market Awareness and Education (MA&E) Committee – This committee comprises principal members, and it is responsible for educational material, press releases, and other related presentations that raise awareness of ATM capabilities in the telecommunications market.
• End-User Roundtable (ENR) – This committee comprises user members, and it is responsible for developing an understanding of user requirements for ATM.

You can contact the ATM forum via their official web site at http://www.atmforum.com/. (more…)

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Installation and configure a Linksys wireless Router needn’t be a difficult challenge, especially with the newer Linksys router models getting easier to set up than ever. Having said that as soon as you use this user manual you will possess your personal wireless network set up quickly enough! How to configure linksys wireless router? First things first let’s take a look at the back for the router.

Whereas the various designs will be there are actually usually the subsequent ports: (more…)

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