network world

Case study

2009-06-23T18:57:00.005-07:00

Case study

Software pricing: issues of client billing
Infosys, one of the major IT companies in India, has developed a new method of pricing software maintenance project. The new method is called as ‘ticket – based pricing. The customer payment will be based on three types of client request or ticket. First, customer may request for small enhancement in the software application. Second, customer may request for big enhancement in the software application and third, request may be for a bug fix. Earlier the methods used for pricing were ‘fixed price’ and ‘time and material-based pricing’. Under the ‘time and material based pricing’, customers are billed based on the number of man-hours spent on a project, while under the fixed price, the customer pays an agreed price that doesn’t vary with the manpower deployed on the project.
Infosys developed this new pricing strategy after examining the current pricing methods. Software application methods become more stable after some time. If the client opted for fixed pricing and his request for software maintenance reduced, still has to pay fixed maintenance charges. Ticket based pricing will provide flexibility to the client. Many IT majors have been trying to decrease the dependence of revenue growth on manpower addition. But this is for the first time such an attempt has been made to bring a transaction-based pricing model. The new move is expected to increase the revenue without a proportional increase in the number of employees. Contrary to this view many industry observers still feel that fixed price or time and material based pricing provide continuous revenue. The excess revenue available from these two methods can be used for reserves or hedging. In case of ticket based pricing client has to negotiate with the company every time.

a. Do you think ticket based pricing will provide continuous revenue to Infosys in the long term? Comment
Answer: Since Infosys may have two type of client that is Big & Small.
a) General small kind of client prefers to outsource their project to avoid the expenditure incurred on the installation of software and maintenance. But because of the ticket based pricing strategy the small client will also think to install the software on the basis of requirement. I think ticket based pricing is one of the best strategy adopted by the Infosys which will definitely a source of continuous revenue in the long run because of the following reason, because now they know that they are able to upgrade or may fix the problem on the basis of demand arise end have to pay accordingly. They need not to pay the fix amount of money regardless of the work alone through which the share of market for Infosys will increase amazingly.
b) Due to the fearness of fix maintenance charged occurred while the fixing of problem any big or small enhancement the big client will generally install the software of which some of its feature may not be useful for the company at all. It may unnecessary become the capital burden for the company and Infosys may not get the business of after sales and service but because of this strategy the company will install the software according to the need and utility. Further the need will arise, the company will be required for the big enhancement or small enhancement of the software end the company have to pay accordingly.
In case of any troubleshoot in the software the company is asked to pay the large fix amount on the basis of installed software

b. Compare three pricing strategies discussed here and choose any one as your choice
Answer: In case of fix price the big client will prefer to purchase new software because the amount to pay for its fixing might have purchase the new one with the enhanced technology this will further shrink the market share and attract the new entrants in the market.
In case of time any material based pricing the company may not incurred profit because The Resource involved in the fixing of problem may be the greater than the actual cost received from the client. But now the company can decides the resource factor to oversee due problem and same the cost.

Psychographic Segmentation

2009-06-23T18:57:00.003-07:00

In Psychographic segmentation, buyers are classified into different groups on the basis of lifestyle or personality and values. People within the same demographic group can exhibit very different psychographic profiles.
a) Lifestyle:
People exhibit different lifestyles and goods they consume express their lifestyles.
Many companies seek opportunities in lifestyle segmentation. But lifestyle segmentation does not always work.

example

2009-06-23T18:57:00.001-07:00

For example, HUL launched ‘pepsodent kids’ for small children.
b) Gender: Gender segmentation has long been applied in clothing, hairstyling, cosmetics and magazines. For example, Emami segmented its personal care business on the basis of gender. For women, it is having Emami naturally fair, and for men it is fair and handsome.
c) Income: Income segmentation is a longstanding practice in such product and service categories as automobiles, clothing, cosmetics and travel. However, income does not always predict the best customers for a given product.
For example, Baja Auto limited, a leading automobile company, different bikes for different commuters. For entry level (less than Rs35000) it is Bajaj CT 100, for mid segment (greater than Rs35000 but less than Rs60000) it is pulsar and for the upper segment greater than Rs
60000 Avenger and Eliminator is positioned.

Demographic Segmentation

2009-06-23T18:56:00.005-07:00

: In demographic segmentation the market is divided into groups on the basis of variable such as age, family size, family lifecycle, gender, income, occupation, education, religion, race, generation, nationality and social class. Demographic variables are the most popular bases for distinguishing customer groups. One reason is that consumers’ wants, preferences and usage rates are often associated with demographic variables. Demographic variables are easy to measure. Even when the target market is described in nondemographic terms, the link back to demographic characteristics is needed in order to estimate the size of the target market and the media that should be used to reach it efficiently. Some of the demographic variables used are :
a) Age and LifeCycle Stage: Consumers’ wants and abilities change with age. On the basis of age, a market can be divided into four parts viz., children, young, adults and old. For consumers of different age groups, different types of products are produced. For instance, different types of readymade garments are produced for consumers of different age groups. A successful marketing manager should understand the age group for which the product would be most suited and determine his marketing policy, pricing policy, advertising policy
etc., accordingly.

Geographic segmentation

2009-06-23T18:56:00.003-07:00

Dividing the market into different geographical units such as nations, states, regions, cities or neighborhoods. The company can operate in one or a few
Geographic areas or operate in all but pay attention to local variations. For example, Bennett, Coleman and co Ltd divided markets according to geographical units for their tabloids. In Bangalore the tabloid is known as Bangalore Mirror where as it is Mumbai Mirror in Mumbai.

Habitual buying behavior

2009-06-23T18:56:00.001-07:00

The low involvement between the brands and few differences between the brands leads to the habitual buying behavior. For example spice powder marketed by MDH, Everest or MTR have very few difference between them and customer do not search the information to purchase particular product. Marketers whose customer represents this category should follow below listed strategies
a. Use price and sales promotions to stimulate product trial.
b. Use more visual aspects than the wordings in the advertisements
c. Television is the better media for this type of products.
d. Use classical conditioning theory to create advertisements.

Variety seeking buying behavior

2009-06-23T18:55:00.003-07:00

When there are significant difference between the brands existing but customer will not involve more while purchasing, marketer identify this behavior as variety seeking buying behavior. Let us discuss the purchasing behavior of customer for biscuits. There are many varieties of biscuits available. One can purchase salt biscuits, cream biscuits, Marie biscuits, and milk biscuits of Britannia, Parle, ITC sun feast and others. The customer who purchased Britannia tiger earlier may purchase Sun feast cream biscuit next time. This doesn’t mean that quality of Britannia tiger is inferior to other brands but customer would like to try the varieties available in the market. In this situations marketer should undertake following steps
a. The market leader should encourage customers to buy repeatedly.
b. Make the product available and visible to the customer in the shopping places.
c. The firm who are not market leader should come out with sales promotion techniques to encourage customer to purchase the product.

Dissonance reducing buying behavior

2009-06-23T18:55:00.001-07:00

The behavior exhibited by the customer when product purchase requires high involvement but only few differences exist. For example, customers who want to purchase CTV will not find many differences between the brands but the price of the product and its technicality makes customer to involve more. One of the major disadvantages of this type of behavior is customer will show post purchase dissonance which is very difficult to control.

Analytical Marketing Systems

2009-06-23T18:54:00.006-07:00

Also known as Marketing Decision Support systems (MDSS), this is a coordinate collection of data, systems, tools and techniques with supporting software and hardware by which an organization gathers and interprets relevant information from business and environment and turns it into a basis for marketing action. All the data which is generated through the other three systems described above are stored in a data base. The storage and retrieval capability of decision support system allows the collection and use of a wide variety of data throughout the company. Senior managers can access the data base and continually and monitor sales, markets, performance of the sales people and other marketing systems as well.

Marketing Research System

2009-06-23T18:54:00.005-07:00

This is the third component of MIS. Marketing Research provides information to marketing manager when he/she encounters marketing problems. This may involve conducting Marketing Research survey by collecting primary data. These surveys may be conducted by the marketing department itself or a it can hire services of an external marketing research agency.

Marketing Intelligence System

2009-06-23T18:54:00.003-07:00

This is a set of procedures and sources used by managers to obtain everyday information about developments in the marketing environment. This system supplies ‘happenings’ data unlike Internal Records System which supplies ‘results’ data. Marketing managers collect data from published sources like books, magazines and journals; by talking to customers, intermediaries and sales personnel. Some companies appoint specialists to gather consumer and competitor information, who does mystery shopping to monitor the performance of their own or competitor’s dealers. Competitor information can also be obtained by buying their product, attending their press conferences, trade shows and reading their annual reports. Companies purchase commercial information from outside suppliers and market research agencies like IMRB, ORG – MARG to obtain competitive data on their sales, advertising expenditures etc., besides their own.

Order to payment cycle

2009-06-23T18:54:00.001-07:00

This includes information on (i) Order to payment cycle and (ii) sales information systems.
Order to payment cycle has a system which records, the timing and size of orders placed by consumers, the payment cycle followed by consumers and the time taken to fulfill the orders, in the shortest possible time. Customers place order through sales people and companies dispatch the goods and receive payments directly or through bank. A proper record system pertaining to order – to – payment cycle management helps mangers to decide on production and dispatch schedule, inventory and accounts receivable schedule and also logistics and distribution management schedules,
Sales Information Systems record everything in the sales Department, starting from Sales Call
Reports to prospects history to Sales territory and quota information for better sales planning and forecasting purpose.

Age structure of the population

2009-06-23T18:53:00.005-07:00

from the following table you can generalize that India is having 48% population who are aged less than 21 and 28% of the population are in the bracket of 2125.
Many marketing companies are focusing on these two segments. For example, Radio Indigo, FM radio station from Jupiter capital venture operates in Bangalore and Goa, plays international music.
Radio indigo targets youth segment who like western music.

Demographic Environment.

2009-06-23T18:53:00.003-07:00

Demography: The study of population characteristics like size, density, location, gender composition, age structure, occupation and religion.
Demography statistics helps companies to develop their products in better way. These statistics are also used in developing proper supply chain, communicating product information and changing the product attributes. Demographic environment is analyzed on the basis of the following factors.

1. Age structure of the population
2. Marital status of the population
3. Geographic distribution of the population
4. Education level
5. Migration
6. Occupation.

Invest strategy

2009-06-23T18:53:00.001-07:00

In this position SBU
a. Should receive ample resources
b. Should support by well financed marketing efforts.
3 Protect strategy: SBU’s in this position should
a. Allocate the resources selectively.
b. Develop strategies which help in maintain its market position.
c. Generate cash needed by other SBU’s.

GE matrix:

2009-06-23T18:52:00.005-07:00

1 Management can use the GE business matrix to classify SBU’s on the basis of two factors
a. Market attractiveness: Market size, entry barriers, competitors, technology and profit margin are some factors used to analyze the market attractiveness.
b. Business position can be determined on the basis of market share, SBU size, R&D capabilities and cost controls
Each cell in the model represented by the particular strategy namely, invest strategy, protect strategy, harvest strategy and divest strategy

Dogs:

2009-06-23T18:52:00.003-07:00

SBU’s in this category generates less cash for the company as it operates in low growth and low market share. Usually companies will not invest in this category and try to liquidate or divest.
BCG matrix for ITC
1. SBU: FMCG
Industry growth rate: 24% (AC Nielson retail audit report 2007)
Company growth rate: 50% (the Hindu business line 19 th January 2008)
Company’s market share : 8% (outlook business)
Largest competitor share: HUL: 54% (outlook business)
Relative market share= 0.14
2. SBU: Paper board
Industry growth rate: 7.2% (the Hindu business line 27 th May 2007)
Company growth rate: 11% (the Hindu business line 19 th January 2008)
Company’s market share: 55%
Largest competitors share: BILT 35%
ITC’s FMCG segment analysis shows that though it is market leader in some categories their overall relative market share is 0.14. Company is in the high growth low relative market share area i.e. question mark position. ITC should invest heavily to convert its SBU position into star.
ITC’s Paperboard industry is in low growth and high market share category i.e. in cash cow segment. It should plan for investing the cash generated from this position into other businesses.

Question Mark

2009-06-23T18:52:00.001-07:00

This category represents high market growth and low market share. SBU’s in this category has two options, either to invest heavily and bring them to star position or divest / liquidate from that position.

Model components:

2009-06-23T18:51:00.003-07:00

Star: This category represents the high market share and high industry growth. SBU’s in this category require large investment to defend their position. SBU will turn as cash cow after some time.
Cash cows: This category represents the low growth rate and high market share which is the characteristic of SBU operating in mature industry. Here company needs less investment to hold their position. Hence it generates more cash or in management terms we say cash cow can be milked.

Axis components:

2009-06-23T18:51:00.001-07:00

1. Market growth rate: The rate at which market is growing
2. Relative market share: Market share of the SBU divided by the market share of the largest competitor.

business portfolio of any one company using BCG matrix, GE matrix, and Ans off model

2009-06-23T18:50:00.000-07:00

BCG matrix: This model is used to identify company’s SBU’s position in the market. This model identifies the SBU’s strength, weaknesses, opportunities and threats on the basis of market growth rate and relative market share. This model is also known as growth share matrix

The Netgear FS105 5-port Key Features

2009-04-01T17:10:00.001-07:00

The Netgear FS105 5-port Key Features
• 5 switched 10/100 Ethernet ports
• Auto-speed and duplex mode sensing
• Vista jacks with built-in LEDs
• Versatile and compatible
• Compact and easy to install
• Plug and play, no software configuration required
• Quiet operation, no fan
• Protocol independent, compatible with TCP/IP, NetWare, Microsoft Windows
• Switch-selectable uplink port
• 12v Plug-pack power supply
• 5 year warranty for switch, 1 year for power supply

The Netgear FS105 5-port

2009-04-01T17:09:00.002-07:00

The Netgear FS105 5-port 10/100 Fast Ethernet switch brings 100 Mbps switching technology to the home and small office marketplace. The FS105 provides a cost effective way to instantaneously boost network performance while preserving your network infrastructure, including installed cabling and desktop software and hardware. Since each port is auto-speed- sensing, installation is plug and play and each connected device can easily be upgraded from 10 to 100 Mbps at any convenient time.
Netgear's workgroup switch range also includes the 8-port FS108 and the 16-port FS116. All are compact, robust, reliable and fast.

Netgear's non-blocking FSM726S and FSM750S Key Features

2009-04-01T17:09:00.001-07:00

• Complete Layer 2 management- SNMP, RMON, VLAN, QoS, port trunking, and more
• 24 10/100 Mbps auto-sensing front ports (FSM726S)
• 48 10/100 Mbps auto-sensing front ports *FSM750S)
• 2 built-in front gigabit uplinks for 1000BASE-T or GBIC module
• 2 rear stacking ports- stack up to 6 units
• Friendly, intuitive browser-based interface for easy observation and control

Netgear's non-blocking FSM726S

2009-04-01T17:08:00.002-07:00

Netgear's non-blocking FSM726S and FSM750S are Layer 2 managed switch that are ideal for medium to large business with arequirement for managed switching and looking for a price/performance solution. The FSM726S has 24 10/100 ports (48 for FSM750S), 2 rear stacking ports and 2 gigabit ports - using either builtin copper gigabit or GBIC slots.
There are two management interface options - as easy-to-use, browser-based interface and a command line interface. Management features include SNMP, RMON, VLAN, QoS, port trunking, Spanning Tree, and port mirroring. All ports are auto-negotiating and support Auto Uplink™ technology. Up to six units may be stacked and the packaging includes a stacking cable and rack-mounting kit.

Netgear’s USB Ethernet adapter model EA101 Key Features

2009-04-01T17:08:00.001-07:00

Key Features
• Provides Ethernet connectivity through USB port
• 10BASE-T compatibility
• Compatible with WIndows 98/ME/2000/XP
• Power, link and collision LED's
• Simple plug and play installation

Netgear’s USB Ethernet adapter

2009-04-01T17:07:00.001-07:00

Netgear’s USB Ethernet adapter model EA101 allows you to connect Windows 98/ME/2000/XP PCs to Ethernet networks without opening your computer. Using an open USB port on either your computer or a USB hub, the EA101 enables you to connect to any standard Ethernet network. You can now add Ethernet networking to your computer without installing any internal cards. Using the latest technology available, NETGEAR once again simplifies networking for small and home based businesses.
Simple plug and play installation
External USB connector allows you to add a network connection to your computer without needing to install any hardware inside your PC. You can share files, play games, or share the Internet through a router without opening your PC.
Standard Ethernet compatible
The EA101 is a standard Ethernet adapter that will allow your computer to connect to any Ethernet network. It is also Windows 98 plug and play compatible so there is no special software to install.
Compact design
The EA101’s compact design allows you to connect to either your desktop PC or take it on the road and connect to your laptop.

Netgear FS116 Key Features

2009-04-01T17:06:00.002-07:00

Key Features
• 16 switched 10/100 Ethernet ports
• Auto-speed and duplex mode sensing
• Vista jacks with built-in LEDs
• Versatile and compatible
• Compact and easy to install
• Plug and play, no software configuration required
• Quiet operation, no fan
• Protocol independent, compatible with TCP/IP, NetWare, Microsoft Windows
• Switch-selectable uplink port
• 12v in-line plug-pack power supply with IEC cord
• 5 year warranty for switch, 1 year for power supply

Netgear FS116

2009-04-01T17:06:00.001-07:00

The Netgear FS116 16-port 10/100 Fast Ethernet switch brings 100 Mbps switching technology to the home and small office marketplace. The FS105 provides a cost effective way to instantaneously boost network performance while preserving your network infrastructure, including installed cabling and desktop software and hardware. Since each port is auto-speed- sensing, installation is plug and play and each connected device can easily be upgraded from 10 to 100 Mbps at any convenient time.
Netgear's workgroup switch range also includes the 5-port FS105 and the 8-port FS108. All are compact, robust, reliable and fast.

Netgear wireless card Key Features

2009-04-01T17:05:00.003-07:00

• Wirelessly connect from your office, home or public access locations with a single card
• Works with all WLAN standards – Fully compatible with IEEE 802.11b, 802.11a and 802.11g
• Up to 152-bit WEP network security helps to keep your wireless transmissions private
• WLAN Manager - users can set up location specific profiles and provides a station list of the available WLAN access points in the area
• Simple to install and use

Netgear wireless card

2009-04-01T17:05:00.001-07:00

Freedom of movement and flexibility of access – NETGEAR's Tri-Band Wireless PC Card gives you both in spades! Remarkably versatile, it lets you access any 802.11a/b/g wireless network from your notebook PC. Put it in your notebook PC and no matter where you are, at home, at the office, at the airport or in other public access areas, you’ll get high-speed access to corporate resources, e-mail, and the Internet. Use it to quickly network employees, saving the time and expense of Ethernet cabling, or use it to upgrade your existing network to the faster wireless standard. Easy to set up and use, it will automatically select the best connection available and adapt the settings to match. And with up to 152-bit WEP encryption, you can rest assured that your wireless network communications are private.

Netgear’s FA312 Ethernet Network Card Key Features

2009-04-01T17:04:00.001-07:00

• 10/100 Mbps half/full duplex
• Auto-sensing (speed and duplex mode) RJ-45 interface
• Quick “one-step” Plug and Play installation
• High-throughput, low CPU utilization
• LED's display LINK, speed and activity
• 3.3 and 5 volt volt PCI - no upgrades required
• Remote Wake-on-LAN
• Limited Lifetime warranty
Operating Systems Supported
• Windows 95/98, NT 3.51 and 4.0, 2000, ME and XP
• Novell Netware Client 32 for DOS, Client for Windows
• Novell Netware Server 4.10, 4.11 and 5.0
• RedHat Linux and SCO OpenServer
If you’re a mobile professional using a Pocket PC or other Windows CE-based mobile computer, you'll want to get hold of NETGEAR’s MA701 Compact Flash Card. It gives handheld devices a new level of connectivity and versatility! Slip it into either a Type I or Type II card slot on your handheld device and you can send and receive e-mail, wirelessly synchronize with your notebook computer, and browse the Internet – all from the palm of your hand.
The indispensable MA701 delivers the ultimate in convenience to enterprise and public IEEE 802.11b wireless LAN systems for access to the Internet, e-mail, and corporate servers. Now you can work wherever you're most productive – in a conference room, on the road, in a coffee shop or hotel, or at the airport. The reliable MA701 protects your privacy with 40/64 and 128-bit WEP encryption and allows you to roam between 802.11b Access Points without resetting or reconfiguring.

Netgear’s FA312 Ethernet Network Card

2009-04-01T17:03:00.000-07:00

Netgear’s FA312 Ethernet Network Card connects PCs to other networked computers, printers, zip drives, routers, network storage and the Internet. Plug it in and you’ll achieve high-speed transfer of all kinds of data.

Convenient! The FA312 with Wake-on-LAN, allows you to remotely access your PCs at any time to perform administrative tasks. Update your system and applications, start management asset programs, download files, track inventory—all this and more can be done outside of working hours, while network traffic is lighter.

Wake-On-Lan
Compatible with the Microsoft-led OnNow industry initiative for instantly available PCs. Supports the Advanced Configuration and Power Interface (ACPI) Remote Wake Up and Magic Packet standard.

Netgear products password

2009-04-01T17:00:00.002-07:00

Netgear ADSL Modem DG632 - V3.3.0a_cx
admin password
- Admin access (HTTP)

Netgear CG814CCR - 2
cusadmin highspeed
- Comcast small business router. Default access at 10.1.10.1
- Admin access (Multi)

Netgear Dg834
n/a admin
- Admin access (Multi)

Netgear Dg834g
admin password
- it should be work also with dg834gt
- Admin access (HTTP)

Netgear DG834GT - 192.168.0.1
admin Password
- Admin access (Multi)

Netgear DM602
admin password
- Admin access (FTP Telnet and HTTP)

Netgear FM114P
n/a (none)
- Admin access (Multi)

Netgear FR114P
admin password
- Admin access (HTTP)

Netgear FSM7326P 24+2 L3 MANAGED PoE Switch
admin (none)
- Admin access (HTTP)

Netgear FVS114 - GR
admin password
- Admin access (HTTP)

Netgear FVS318
admin password
- Admin access (HTTP)

Netgear FWG114P
n/a admin
- password access (Multi)

Netgear GS724t - V1.0.1_1104
n/a password
- Admin access (HTTP)

Netgear GSM7224
admin (none)
- Admin access (HTTP)

Netgear ME102
(none) private
- Standard IP-Address is 192.168.0.5
- Admin access (SNMP)

Netgear MR-314 - 3.26
admin 1234
- Admin access (HTTP)

Netgear MR314
admin 1234
- Admin access (Multi)

Netgear MR814
admin password
- Admin access (HTTP)

Netgear RM356 - None
(none) 1234
- shutdown the router via internet
- Admin access (Telnet)

Netgear RO318
admin 1234
- Admin access (Multi)

Netgear Router/Modem
admin password
- Admin access (Multi)

Netgear RP114 - 3.20-3.26
admin 1234
- default http://192.168.0.1
- Admin access (HTTP)

Netgear RP114 - 3.26
(none) 1234
- telnet 192.168.0.1
- Admin access (Telnet)

Netgear RP614
admin password
- Admin access (HTTP)

Netgear RT314
admin admin
- Admin access (HTTP)

Netgear Sc101
admin password
- Admin access (management software)

Netgear WG602 - 1.7.x
admin password
- Default IP: DHCP or 192.168.0.227
- Admin access (HTTP)

Netgear WG602 - Firmware Version 1.04.0
super 5777364
- Admin access (HTTP)

Netgear WG602 - Firmware Version 1.5.67
super 5777364
- Admin access (HTTP)

Netgear WG602 - Firmware Version 1.7.14
superman 21241036
- Admin access (HTTP)

Netgear WGR614 - v4
admin password
- 192.168.0.1 OR www.routerlogin.net
- Admin access (Multi)

Netgear WGR614 - v6
admin draadloos
- Dutch routers
- Admin access (HTTP)

Netgear WGT624
Gearguy Geardog

- Admin access (Serial console)

Netgear WGT624 - 2
admin password
- Admin access (HTTP)

Netgear WGT634U
admin password
- Admin access (HTTP)

Netgear Wifi Router - WGT 624 v3
admin password
- slawcio26
- Admin access (HTTP)

NETGEAR

2009-04-01T17:00:00.001-07:00

Introduction
This Quick Tip lists the default username and password used to login to the web management console (and telnet console where supported) on all current models of Netgear routers.
The defaults are set when the router is shipped from the factory, and if the configuration is later reset.
For security reasons, we recommend that you change the password on your router. However if you do change your password, be sure to remember it or record it somewhere safe.
[It is not possible to change the default username]
If you lose the password, you will need to reset the router configuration (and lose all other configuration settings as well) to be able to login to the router.

Single-Pair High-speed Digital Subscriber Line

2009-01-23T17:35:00.001-08:00

Single-pair High-speed Digital Subscriber Line (SHDSL) is a form of DSL, a data communications technology that enables faster data transmission over copper telephone lines than a conventional voiceband modem can provide. Compared to ADSL, SHDSL employs frequencies that include those used by traditional POTS telephone services to provide equal transmit and receive (i.e. symmetric) data rates. As such, a frequency splitter, or microfilter, can not be used to allow a telephone line to be shared by both an SHDSL service and a POTS service at the same time. Support of symmetric data rates has made SHDSL a popular choice by businesses for PBX, VPN, web hosting and other data services.

SHDSL features symmetrical data rates from 192 kbit/s to 2,304 kbit/s of payload in 64 kbit/s increments for one pair and 384 kbit/s to 4,608 kbit/s in 128 kbit/s increments for two pair applications. The reach varies according to the loop rate and noise conditions (more noise or higher rate means decreased reach) and may be up to 3,000 meters. The two pair feature may alternatively be used for increased reach applications by keeping the data rate low. Halving the data rate per pair will provide similar speeds to single pair lines while increasing the error/noise tolerance.

An optional extended SHDSL mode allows symmetric data rates up to 5696 kbit/s on one pair. Higher data rates may be achieved using two or up to four copper pairs.

Wireless ISP

2009-01-23T17:34:00.000-08:00

This typically employs the current low-cost 802.11 Wi-Fi radio systems to link up remote locations over great distances, but can use other higher-power radio communications systems as well.

Traditional 802.11b was licensed for omnidirectional service spanning only 100-150 meters (300-500 ft). By focusing the signal down to a narrow beam with a Yagi antenna it can instead operate reliably over a distance of many miles.

Rural Wireless-ISP installations are typically not commercial in nature and are instead a patchwork of systems built up by hobbyists mounting antennas on radio masts and towers, agricultural storage silos, very tall trees, or whatever other tall objects are available. There are currently a number of companies that provide this service. A wireless Internet access provider map for USA is publicly available for WISPS.

Satellite Internet

2009-01-23T17:33:00.002-08:00

This employs a satellite in geostationary orbit to relay data from the satellite company to each customer. Satellite Internet is usually among the most expensive ways of gaining broadband Internet access, but in rural areas it may only compete with cellular broadband. However, costs have been coming down in recent years to the point that it is becoming more competitive with other broadband options. German ISP, Filiago, offers the ASTRA2Connect satellite Internet system for €320 (equipment) plus €100 (registration) and a flat rate monthly fee dependent on bandwidth - from €20 for 256Kbit/s download, 64Kbits/s upload, to €80 for 2048Kbit/s download, 128Kbits/s upload.[6]

Satellite Internet also has a high latency problem caused by the signal having to travel 35,000 km (22,000 miles) out into space to the satellite and back to Earth again. The signal delay can be as much as 500 milliseconds to 900 milliseconds, which makes this service unsuitable for applications requiring real-time user input such as certain multiplayer Internet games and first-person shooters played over the connection. Despite this, it is still possible for many games to be played, but the scope is limited to real-time strategy or turn-based games. The functionality of live interactive access to a distant computer can also be subject to the problems caused by high latency. These problems are more than tolerable for just basic email access and web browsing and in most cases are barely noticeable.

There is no simple way to get around this problem. The delay is primarily due to the speed of light being 300,000 km/second (186,000 miles per second). Even if all other signaling delays could be eliminated it still takes the electromagnetic wave 233 milliseconds to travel from ground to the satellite and back to the ground, a total of 70,000 km (44,000 miles) to travel from the user to the satellite company.

Since the satellite is usually being used for two-way communications, the total distance increases to 140,000 km (88,000 miles), which takes a radio wave 466 ms to travel. Factoring in normal delays from other network sources gives a typical connection latency of 500-700 ms. This is far worse latency than even most dial-up modem users' experience, at typically only 150-200 ms total latency.

Most satellite Internet providers also have a FAP (Fair Access Policy). Perhaps one of the largest disadvantages of satellite Internet, these FAPs usually throttle a user's throughput to dial-up data rates after a certain "invisible wall" is hit (usually around 200 MB a day). This FAP usually lasts for 24 hours after the wall is hit, and a user's throughput is restored to whatever tier they paid for. This makes bandwidth-intensive activities nearly impossible to complete in a reasonable amount of time (examples include P2P and newsgroup binary downloading).

The European ASTRA2Connect system has a FAP based on a monthly limit of 2Gbyte of data downloaded, with download data rates reduced for the remainder of the month if the limit is exceeded.

ISDN

2009-01-23T17:33:00.001-08:00

Integrated Service Digital Network (ISDN) is one of the oldest broadband digital access methods for consumers and businesses to connect to the Internet. It is a telephone data service standard. Its use in the United States peaked in the late 1990s prior to the availability of DSL and cable modem technologies. Broadband service is usually compared to ISDN-BRI because this was the standard broadband access technology that formed a baseline for the challenges faced by the early broadband providers. These providers sought to compete against ISDN by offering faster and cheaper services to consumers.

A basic rate ISDN line (known as ISDN-BRI) is an ISDN line with 2 data "bearer" channels (DS0 - 64 kbit/s each). Using ISDN terminal adapters (erroneously called modems), it is possible to bond together 2 or more separate ISDN-BRI lines to reach bandwidths of 256 kbit/s or more. The ISDN channel bonding technology has been used for video conference applications and broadband data transmission.

Primary rate ISDN, known as ISDN-PRI, is an ISDN line with 23 DS0 channels and total bandwidth of 1,544 kbit/s (US standard). ISDN E1 (European standard) line is an ISDN lines with 30 DS0 channels and total bandwidth of 2,048 kbit/s. Because ISDN is a telephone-based product, a lot of the terminology and physical aspects of the line are shared by the ISDN-PRI used for voice services. An ISDN line can therefore be "provisioned" for voice or data and many different options, depending on the equipment being used at any particular installation, and depending on the offerings of the telephone company's central office switch. Most ISDN-PRI's are used for telephone voice communication using large PBX systems, rather than for data. One obvious exception is that ISPs usually have ISDN-PRI's for handling ISDN data and modem calls.

It is mainly of historical interest that many of the earlier ISDN data lines used 56 kbit/s rather than 64 kbit/s "B" channels of data. This caused ISDN-BRI to be offered at both 128 kbit/s and 112 kbit/s rates, depending on the central office's switching equipment.

Broadband Internet access

2009-01-23T17:32:00.000-08:00

Broadband Internet access, often shortened to just broadband, is high data rate Internet access—typically contrasted with dial-up access over a modem.

Dial-up modems are generally only capable of a maximum bitrate of 56 kbit/s (kilobits per second) and require the full use of a telephone line—whereas broadband technologies supply at least double this bandwidth and generally without disrupting telephone use.

Although various minimum bandwidths have been used in definitions of broadband, ranging up from 64 kbit/s up to 1.0 Mbit/s, the 2006 OECD report [1] is typical by defining broadband as having download data transfer rates equal to or faster than 256 kbit/s, while the United States FCC, as of 2008, defines broadband as anything above 768 kbit/s. [2] [3] The trend is to raise the threshold of the broadband definition as the marketplace rolls out faster services each year.[3]

Data rates are defined in terms of maximum download because several common consumer broadband technologies such as ADSL are "asymmetric"—supporting much slower maximum upload data rate than download.

How ADSL works

2009-01-23T17:31:00.002-08:00

On the wire

Currently, most ADSL communication is full-duplex. Full-duplex ADSL communication is usually achieved on a wire pair by either frequency-division duplex (FDD), echo-cancelling duplex (ECD), or time-division duplexing (TDD). FDD uses two separate frequency bands, referred to as the upstream and downstream bands. The upstream band is used for communication from the end user to the telephone central office. The downstream band is used for communicating from the central office to the end user.
Frequency plan for ADSL. The red area is the frequency range used by normal voice telephony (PSTN), the green (upstream) and blue (downstream) areas are used for ADSL.

With standard ADSL (annex A), the band from 25.875 kHz to 138 kHz is used for upstream communication, while 138 kHz – 1104 kHz is used for downstream communication. Each of these is further divided into smaller frequency channels of 4.3125 kHz. These frequency channels are sometimes termed bins. During initial training, the ADSL modem tests each of the bins to establish the signal-to-noise ratio at each bin's frequency. The distance from the telephone exchange and the characteristics of the cable mean that some frequencies may not propagate well, and noise on the copper wire, interference from AM radio stations and local interference and electrical noise at the customer end mean that relatively high levels of noise are present at some frequencies, so considering both effects the signal-to-noise ratio in some bins (at some frequencies) may be good or completely inadequate. A bad signal-to-noise ratio measured at certain frequencies will mean that those bins will not be used, resulting in a reduced maximum link capacity but with an otherwise functional ADSL connection.

The DSL modem will make a plan on how to exploit each of the bins sometimes termed "bits per bin" allocation. Those bins that have a good signal-to-noise ratio (SNR) will be chosen to transmit signals chosen from a greater number of possible encoded values (this range of possibilities equating to more bits of data sent) in each main clock cycle. This number must of possibilities must not be so large that the receiver might mishear which one was intended in the presence of noise. Noisy bins may only be required to carry as few as two bits, a choice from only one of four possible patterns, or only one bit per bin in the case of ADSL2+, and really noisy bins are not used at all. If the pattern of noise versus frequencies heard in the bins changes, the DSL modem can alter the bits-per-bin allocations, in a process called "bitswap", where bins that have become more noisy are only required to carry fewer bits and other channels will be chosen to be given a higher burden. The data transfer capacity the DSL modem therefore reports is determined by the total of the bits-per-bin allocations of all the bins combined. Lower signal-to-noise ratios and more bins being in use gives a higher total link capacity, higher signal-to-noise ratios or fewer bins being used gives a low link capacity.

The total maximum capacity derived from summing the bits-per-bins is reported by DSL modems and is sometimes termed sync rate. This will always be rather misleading as the true maximum link capacity for user data transfer rate will be significantly lower because extra data is transmitted that is termed protocol overhead, a reduced figure of around 84-87% at most for PPPoA connnections being a common example. In addition some ISPs will have traffic policies that limit maximum transfer rates further in the networks beyond the exchange, and traffic congestion on the Internet, heavy loading on servers and slowness or inefficiency in customers' computers may all contribute to reductions below the maximum attainable.

The choices the DSL modem make can also be either conservative, where the modem chooses to allocate fewer bits per bin than it possible could, a choice which makes for a slower connection, or less conservative in which more bits per bin are chosen in which case there is a greater risk case of error should future signal-to-noise ratios deteriorate to the point where the bits-per-bin allocations chosen are too high to cope with the greater noise present. This conservatism involving a choice to using fewer bits per bin as a safeguard against future noise increases is reported as the signal-to-noise ratio margin or SNR margin. The telephone exchange can indicate a suggested SNR margin to the customer's DSL modem when it initially connects, and the modem may make its bits-per-bin allocation plan accordingly. A high SNR margin will mean a reduced maximum throughput but possibly greater reliability. A low SNR margin will mean high speeds provided the noise level does not increase too much, otherwise the connection will have to be dropped and renegotiated. ADSL2+ can better accommodate such circumstances, offering a feature termed seamless rate adaptation (SRA), which can accomodate changes in total link capacity with less disruption to communications.

Vendors may support usage of higher frequencies as a proprietary extension to the standard. However, this requires matching vendor-supplied equipment on both ends of the line, and will likely result in crosstalk problems that affect other lines in the same bundle.

There is a direct relationship between the number of channels available and the throughput capacity of the ADSL connection. The exact data capacity per channel depends on the modulation method used.

Installation issues

Due to the way it uses the frequency spectrum, ADSL deployment presents some issues. It is necessary to install appropriate frequency filters at the customer's premises, to avoid interferences with the voice service, while at the same time taking care to keep a clean signal level for the ADSL connection.

In the early days of DSL, installation required a technician to visit the premises. A splitter or microfilter was installed near the demarcation point, from which a dedicated data line was installed. This way, the DSL signal is separated earlier and is not attenuated inside the customer premises. However, this procedure is costly, and also caused problems with customers complaining about having to wait for the technician to perform the installation. As a result, many DSL vendors started offering a self-install option, in which they ship equipment and instructions to the customer. Instead of separating the DSL signal at the demarcation point, the opposite is done: the DSL signal is filtered at each phone outlet by use of a low-pass filter for voice and a high-pass filter for data, usually enclosed in what is known as a microfilter. This microfilter can be plugged directly into any phone jack, and does not require any rewiring at the customer's premises.

A side effect of the move to the self-install model is that the DSL signal can be degraded, especially if more than 5 voiceband devices are connected to the line. The DSL signal is now present on all telephone wiring in the building, causing attenuation and echo. A way to circumvent this is to go back to the original model, and install one filter upstream from all telephone jacks in the building, except for the jack to which the DSL modem will be connected. Since this requires wiring changes by the customer and may not work on some household telephone wiring, it is rarely done. It is usually much easier to install filters at each telephone jack that is in use.

DSL signals may be degraded by older telephone line surge protectors, poorly designed microfilters and by long telephone extension cords. Telephone extension cords are typically made with small-gauge braided copper conductors, which are more susceptible to electromagnetic interference and have more attenuation than single-strand copper wires typically wired to telephone jacks. Within the customer premises, electrical noise, poor mains quality and radio frequency interference can all pollute the DSL signal, and these effects are especially significant where the customer has a long phone line on which the received signal levels are greatly attenuated, so signal levels are low relative to any local noise that may be introduced. This will have the effect of reducing speeds or even causing unreliable connections.

Asymmetric Digital Subscriber Line

2009-01-23T17:31:00.001-08:00

Asymmetric Digital Subscriber Line (ADSL) is a form of DSL, a data communications technology that enables faster data transmission over copper telephone lines than a conventional voiceband modem can provide. It does this by utilizing frequencies that are not used by a voice telephone call. A splitter - or microfilter - allows a single telephone connection to be used for both ADSL service and voice calls at the same time. Because phone lines vary in quality and were not originally engineered with DSL in mind, it can generally only be used over short distances, typically less than 4km

Digital subscriber line access multiplexer

2009-01-23T17:30:00.000-08:00

A Digital Subscriber Line Access Multiplexer (DSLAM, often pronounced dee-slam) allows telephone lines to make faster connections to the Internet. It is a network device, located in the telephony exchanges of the service providers, that connects multiple customer Digital Subscriber Lines (DSLs) to a high-speed Internet backbone line using multiplexing techniques. By placing remote DSLAMs at locations remote to the telephone company central office (CO), telephone companies provide DSL service to locations previously beyond effective range.

* DSL modems vary in data speed from hundreds of kilobits per second to many megabits, while voiceband modems are nominally 56K modems and actually limited to approximately 50 kb/s.

* DSL modems exchange data with only the DSLAM to which they are wired, which in turn connects them to the Internet, while most voiceband modems can dial directly anywhere in the world.

* DSL modems are intended for particular protocols and sometimes won't work on another line even from the same company, while most voiceband modems use international standards and can "fall back" to find a standard that will work.[citation needed]

Most of these differences are of little interest to consumers, except the greater speed of DSL and the ability to use the telephone even when the computer is online.

Because a single phone line commonly carries DSL and voice, DSL filters are used to separate the two uses.

RAID 3

2008-10-22T19:20:00.002-07:00

On RAID 3 systems, datablocks are subdivided (striped) and written in parallel on two or more drives. An additional drive stores parity information. You need at least 3 disks for a RAID 3 array.

Since parity is used, a RAID 3 stripe set can withstand a single disk failure without losing data or access to data.
Advantages
RAID-3 provides high throughput (both read and write) for large data transfers.
Disk failures do not significantly slow down throughput.
Disadvantages
This technology is fairly complex and too resource intensive to be done in software.
Performance is slower for random, small I/O operations.
Ideal use
RAID 3 is not that common in prepress.

RAID 1: mirroring

2008-10-22T19:20:00.001-07:00

Data are stored twice by writing them to both the data disk (or set of data disks) and a mirror disk (or set of disks) . If a disk fails, the controller uses either the data drive or the mirror drive for data recovery and continues operation. You need at least 2 disks for a RAID 1 array.

RAID 1 systems are often combined with RAID 0 to improve performance. Such a system is sometimes referred to by the combined number: a RAID 10 system.
Advantages
RAID 1 offers excellent read speed and a write-speed that is comparable to that of a single disk.
In case a disk fails, data do not have to be rebuild, they just have to be copied to the replacement disk.
RAID 1 is a very simple technology.
Disadvantages
The main disadvantage is that the effective storage capacity is only half of the total disk capacity because all data get written twice.
Software RAID 1 solutions do not always allow a hot swap of a failed disk (meaning it cannot be replaced while the server keeps running). Ideally a hardware controller is used.
Ideal use
RAID-1 is ideal for mission critical storage, for instance for accounting systems. It is also suitable for small servers in which only two disks will be used.

RAID 0: striping

2008-10-22T19:17:00.002-07:00

In a RAID 0 system, data are split up in blocks that get written across all the drives in the array. By using multiple disks (at least 2) at the same time, RAID 0 offers superior I/O performance. This performance can be enhanced further by using multiple controllers, ideally one controller per disk.

Advantages
RAID 0 offers great performance, both in read and write operations. There is no overhead caused by parity controls.
All storage capacity can be used, there is no disk overhead.
The technology is easy to implement.
Disadvantages
RAID 0 is not fault-tolerant. If one disk fails, all data in the RAID 0 array are lost. It should not be used on mission-critical systems.
Ideal use
RAID 0 is ideal for non-critical storage of data that have to be read/written at a high speed, e.g. on a PhotoShop image retouching station.

RAID levels

2008-10-22T19:17:00.001-07:00

RAID stands for Redundant Array of Inexpensive Disks. A RAID system consists of two or more disks working in parallel. They appear as one drive to the user, and offer enhanced performance or security (or both).
The software to perform the RAID-functionality and control the hard disks can either be located on a separate controller card (a hardware RAID controller) or it can simply be a driver. Both Windows NT 4 and 2000 include a software RAID solution. Hardware RAID controllers cost more than pure software but they also offer better performance.
Most RAID-systems are based on SCSI, although implementations using IDE disks or FC (fibre channel) disks also exist. There are even systems that use IDE disks internally but that have a SCSI-interface for the host system.
There are different RAID levels, each suiting specific situations. RAID levels are not standardized by an industry group. This explains why companies are sometimes creative and come up with their own unique implementations.
Sometimes disks in a RAID system are defined as JBOD, which stands for 'just a bunch of disks'. This means that those disks do not use a specific RAID level and are used as if they were stand-alone disks. This is often done for disks that contain swap files or spooling data.

RAID TECHNOLOGY.

2008-10-22T19:16:00.001-07:00

Short for Redundant Array of Independent (or Inexpensive) Disks, a category of disk drives that employ two or more drives in combination for fault tolerance and performance. RAID disk drives are used frequently on servers but aren't generally necessary for personal computers.
There are number of different RAID levels:
• Level 0 -- Striped Disk Array without Fault Tolerance: Provides data striping (spreading out blocks of each file across multiple disk drives) but no redundancy. This improves performance but does not deliver fault tolerance. If one drive fails then all data in the array is lost.
• Level 1 -- Mirroring and Duplexing: Provides disk mirroring. Level 1 provides twice the read transaction rate of single disks and the same write transaction rate as single disks.
• Level 2 -- Error-Correcting Coding: Not a typical implementation and rarely used, Level 2 stripes data at the bit level rather than the block level.
• Level 3 -- Bit-Interleaved Parity: Provides byte-level striping with a dedicated parity disk. Level 3, which cannot service simultaneous multiple requests, also is rarely used.
• Level 4 -- Dedicated Parity Drive: A commonly used implementation of RAID, Level 4 provides block-level striping (like Level 0) with a parity disk. If a data disk fails, the parity data is used to create a replacement disk. A disadvantage to Level 4 is that the parity disk can create write bottlenecks.
• Level 5 -- Block Interleaved Distributed Parity: Provides data striping at the byte level and also stripe error correction information. This results in excellent performance and good fault tolerance. Level 5 is one of the most popular implementations of RAID.
• Level 6 -- Independent Data Disks with Double Parity: Provides block-level striping with parity data distributed across all disks.
• Level 0+1 – A Mirror of Stripes: Not one of the original RAID levels, two RAID 0 stripes are created, and a RAID 1 mirror is created over them. Used for both replicating and sharing data among disks.
• Level 10 – A Stripe of Mirrors: Not one of the original RAID levels, multiple RAID 1 mirrors are created, and a RAID 0 stripe is created over these.
• Level 7: A trademark of Storage Computer Corporation that adds caching to Levels 3 or 4.
• RAID S: EMC Corporation's proprietary striped parity RAID system used in its Symmetrix storage systems.

SCSI Buses - An introduction to SCSI technology

2008-10-22T19:15:00.001-07:00

Introduction
Credit for this information should go to Dinah McNutt.

SCSI is an 8-bit parallel I/O bus.
It comes in 3 flavours, SCSI-1, SCSI-2 and SCSI-3. SCSI-1 is the only one which is an official standard, as of the middle of 1994. The current SCSI-1 standard was finalized in 1986.
Incompatibility between SCSI host adapters and SCSI devices is still a monumental problem. I speak from experience. Many manufacturers who produce allegedly SCSI-2 devices actually produce incompatible SCSI-2 devices.
Worse, SCSI hard disk prices are 2 or 3 times the price is same-size IDE hard disks.

Devices
Up to 8 devices can be attached to a single SCSI bus. One of these is the host adapter, leaving room for 7 'real' devices.
No matter how many devices are actually connected, only one pair of devices can communicate with each other at any one time.

Addresses
SCSI uses a 3-bit addressing scheme, where each device is assigned an address ranging from 0 to 7.
Device 7 has the highest priority, so the host computer is usually assigned to be device 7.

Initiator/Target = Client/Server
Communication occurs when the initiator, which is typically the host computer, originates a request, and the target (eg a device controller) performs the request.
The SCSI lets all devices communicate with each other, but some devices are implemented in such a way that the cannot initiate communications.

Electrical Specifications
There are 2 electrical specifications for SCSI: single-ended and differential.
Single-ended is limited to a maximum cable length of 6m.
Differential supports cables up to 25 m in length. Differential is much more expensive to design and manufacture.

Protocols
SCSI devices can use either asynchronous or synchronous communication protocols.
In the original SCSI specification, synchronous communication allowed speeds of up to 5 Mb/sec. Note that if your SCSI bus is short, asychronous communication can be fast.

SCSI-2
SCSI-2 extends the original Common Command Set (CCS) to support CD-ROMs, scanners, communications devices and optical memory drives (eg WORM and erasable media).
SCSI-2 supports 8-bit, 16-bit and 32-bit buses; also it supports up to 10 Mb/sec on 8-bit buses, and thus up to 40 Mb/sec on 32-bit buses.

Fast-Wide SCSI-2
5 Mb/sec 10 Mb/sec
8-bit Fast
16-bit Wide Fast-Wide
32-bit Wide Fast-Wide
The SCSI-2 specification allows fast SCSI only on differential SCSI buses, but in practice vendors sell single-ended fast SCSI devices.

SCSI-3
SCSI-3 is planned to support optical fibre, longer cables, and more that 8 targets per bus.
Also, it will run at up to 20 Mb/sec.
SCSI-3 will include a specification for serial SCSI over fibre-optic or high-speed copper cabling. Speeds aimed for are 51 Mb/sec up to 1 Gb/sec. These serial proposals are called IEEE P1394 (nicknamed FireWire), Fibre Channel and Serial Storage Architecture (SSA).
Another advantage of serial is that fewer wires are required, simplifying cabling. Frankly though, mixing serial SCSI and parallel SCSI looks like a recipe for disaster

SCSI TERMINATION

2008-10-22T19:14:00.000-07:00

On SCSI drives, the Host Adapter also has resistors. These are needed to terminate both ends of the bus. Since the SCSI bus can have up to 7 devices attached to it, only the Host Adapter and the device farthest from it will retain the resistors. All devices in-between should have theirs removed. With the advent of increased use of SCSI for peripherals comes the chance that one day you'll need an SCSI terminating resistor. Prepare for a shock, because you might be very surprised at the prices charged, for what you get. Many Manufacturers still have SCSI peripheral hardware priced for the Workstation market, not the PC market. We may see these prices erode as more PCs adopt SCSI as their disk interface of choice, but for now be prepared to pay a premium for anything to do with SCSI. So here you are, with a disk drive mounted internally, and a CD-ROM hanging off the back of the PC. Everything looks great, but it just doesn't work... Maybe it doesn't even recognise the CD-ROM. You've checked the connectors, and everything looks good... So what's the problem? Well, did you check the terminators? (Say Whaaat??) Improper termination of an SCSI bus can raise havoc with the Host Adapter's interface circuit, and result in missing peripherals, or intermittent operation and possible loss of data. Well, here's a way to build an inexpensive terminator that will connect to the second SCSI connector on many SCSI peripherals.

SCSI termination is very important, there must be two terminator on each SCSI chain, one at the beginning and one at the end device chain. The terminator must be within 10 centimeters (4 inches) of each end of the chain on the bus. Take a look at figure 1 to see what is acceptable and what's not when terminating SCSI devices.
The following ARE acceptable:
+------------+----------+-----------+-----------+---------+
| | | | | |
DEVICE A Unconnected Unconnected Unconnected DEVICE B DEVICE C
Terminated (adapter-Terminated)
+------------+----------+-----------+-----------+---------+
| | | | | |
DEVICE A Unconnected DEVICE B Unconnected Unconnected DEVICE C
Terminated (adapter) Terminated
+------------+----------+-----------+-----------+---------+
| | | | | |
Terminated DEVICE A DEVICE B Unconnected Unconnected DEVICE C
(adapter) Terminated
The following ARE NOT allowed:
+------------+----------+-----------+-----------+---------+
| | | | | |
DEVICE A DEVICE B DEVICE C Unconnected Unconnected Unconnected
Terminated (adapter) Terminated
+------------+----------+-----------+-----------+---------+
| | | | | |
Unconnected DEVICE A DEVICE B DEVICE C Unconnected Unconnected
Terminated (adapter) Terminated
Figure 1: Correct and wrong way of connecting SCSI devices
Note: When putting the host adapter in the middle of the chain,
you must disable the host terminators. If this is impossible you MUST put the host adapter at either end of the cable.
SCSI CONNECTORS

Names
External Connector Types (not to scale)
Maximum
Speed
(MB/s) Number of
Devices (A,B)
Max Total
Length of Cable Uses Comments
SCSI-1
50-pin low-density (SCSI-1, Centronix, A-Cable)

>Apple DB-25C

SCSI-1 5 8 6 mD
Scanners, Zip drives, hard drives, etc. The DB-25 version is standard on Macintosh® computers.C
Many peripherals are available.
SCSI-2
SCSI-2 (Fast SCSI, Fast Narrow)
50-pin low-density (SCSI-1, Centronix, A-Cable)

50-pin high-density (SCSI-2)

10 8 ²4 devices: 3 m
5+ devices: 1.5 m Desktop hard drives, scanners, CD-ROM drives, CD-Recordable drives, and removables Backward-compatible with SCSI-1. Many products available.
"Wide" products use 16-bit instead of 8-bit data paths.
Fast Wide SCSI (Wide SCSI) 68-pin

20 16 ²4 devices: 3 m
5+ devices: 1.5 m Faster hard drives, workstations, servers and RAID systems Backward-compatible with SCSI-1. Many products available.
"Wide" products use 16-bit instead of 8-bit data paths.
SCSI-3
50-pin low-density (SCSI-1, Centronix, A-Cable)

50-pin high-density (SCSI-2)

68-pin

Ultra SCSI
(SCSI-3, Fast-20, Ultra Narrow) 20 8 1.5 mD,LVD
Newer and faster hard drives, performance desktop, workstations, servers, RAID systems Backward-compatible with previous SCSI versions.
SCSI-3 specification still under consideration, but products are available that meet current specifications. "SCAM" specification allows for devices to set own ID automatically.
Some variations of SCSI-3 are hot-pluggable.
Ultra2 devices available now.
Ultra3 devices under development.
Wide Ultra SCSI
(Fast Wide 20) 40 16 1.5 mD,LVD

Ultra2 SCSI 40 8 12 m
Wide Ultra2 SCSI 80 16 12 m
Ultra3 SCSI 80 8 12 m
Wide Ultra3 SCSI 160 16 12 m

(A): Including Host Adapter
(B): Per channel
(C): The Apple DB-25 is not an official standard. It uses SCSI-2 protocols, but at SCSI-1 speeds.
(D): Differential allows for cable lengths of up to 25 meters.
(E): The DB-9 Fibre Channel connector is the industry standard, but only the four outer pins are live.

CABLING

2008-10-22T19:13:00.003-07:00

Internal devices use a 50 pin dual inline connector and a flat ribbon cable. Multiple connectors are usually attached to it in increments of around 12 inches (yet they might be farther apart). You can use any connector on the cable and in any order.

External devices use a different cable and connector for obvious reasons. The cable is usually consisted of 25 twisted pair wires, so you get a total of 50 wires. Each external device has two connectors on it's back side, they are connected to each other pin for pin and are used to connect the next device in the daisy chain or to connect the terminator. This means that you need a cable for each additional external device.

The standard SCSI connector has 50 pins in two rows and is termed as the type A connector from the SCSI specifications, this connector looks like a Centronics printer connector yet has 50 pins instead of 36. Some devices use a regular 25 pin D-shell connector, this connector is good, but can only handle single ended SCSI because they don't have enough connections.

SCSI-2 specified a new cable for wide SCSI, since the original Type A cable does not have enough connections on it. The SCSI-2 specifications indicates the use of a second cable described as the B cable, yet most developers did not follow this path and use a similar cable known as the type P cable. This cable has a 68 pin connector arranged in two rows of 34 pins just like the B cable. The difference is in the pin assignments on the connector. The B cable has since been abandoned and the standard is now the P cable.

SINGLE ENDED OR DIFFERENTIAL

2008-10-22T19:13:00.001-07:00

The original design of the SCSI standard allowed two different types of buses, the single ended and differential. Single ended SCSI uses a single ended electrical signal (also refered to as unbalanced), this means that a single wire is used as a common ground return path for all signal lines. As of in the differential SCSI (refered to as balanced) each signal line has it's own return path and is also isolated from the reference ground. The cable uses twisted pair wiring, this makes it less prone to electrical interference and to picking up noise. This means that differential SCSI needs more wires and more electronics, and consequently also means higher prices, so as you guest most users systems use single ended SCSI because their cheaper and work good in most applications, like small systems and where electrical noise is not a problem.

Since differential SCSI is less prone to electical interference the cable lengths are greatly improved. On single ended SCSI, the cable length is limited to 6 meters (around 20 feet) and with differential SCSI the cable length can span up to 25 meters (about 82 feet). The shortest cable must not be less than 30 centimeters (12 inches) between each device. For example, if you have 3 device connected to the host adapter, the minimum lenght of the cable should be 1 meter (3 feet).

HARDWARE

2008-10-22T19:12:00.002-07:00

The basic SCSI bus can connect up to seven devices and 1 host adapter on it, the bus uses 3 address lines which gives you a possibility of 8 addresses. Each device is assigned a SCSI address from 0 to 7 where 7 is reserved as the host adapter. The remaining 7 addresses are used for any device connected anywhere on the bus. Each address is assigned a priority, where 7 (the host adapter) has the top priority and 0 beeing the lowest priority.

Each device can be assigned any address (except for address 7) and is user selected via DIP switches or jumpers. No two devices can have the same address on the same SCSI chain, internal nor external. Usually you can assign any address number to a device as long as the software or drivers for the specific device allow it. Some devices will not let you the freedom of selecting the address, in these cases you must make sure that the predifined address on the device does not conflict with other devices already in use. For example some systems will force you to assign the address 0 on the boot hard drive, this is true for most host adapters that emulate the Western Digital WD1002 controller

APPLE SCSI

2008-10-22T19:12:00.001-07:00

Unlike in the PC world, the Apple standardised on one drive interface, SCSI. Also, Apple standardised on a 25 pin connector for external connections. However, Apple decided not to implement the complete ANSI spec., so one must be careful that peripherals used are certified to work with Apple's SCSI bus. Apple also developed it's own pin-configuration. The Apple and Future Domain 25-pin SCSI connectors are as close to "Standards" as there are in the world of PCs. But the real ANSI Standard called for a 50 pin connector commonly referred to as a "Centronics" type (made popular by the Centronics printer company). Instead of the 25 staggered pins of the Apple & Future Domain type connectors, the Centronics type uses 2 parallel rows of 25 pins. This arrangement allows the use of extra grounds for better isolation.

TECH BASICS

2008-10-22T19:10:00.000-07:00

SCSI - SCSI stands for Small Computer System Interface.

The normal internal cable for SCSI is a 50 conductor ribbon, with all odd numbered conductors grounded. Two conductors, numbers 25 & 26, are often left not-connected, as they deal with Terminator power, and can be easily shorted by cable reversals. There are no twists in this cable, and it's length may be a maximum of 6 meters. But one is advised to use minimum lengths to improve timing. Up to seven drives, or devices may be attached to an SCSI cable. Each is daisy-chained on the cable, or, when a device has two connectors, another cable may be "spliced" into the chain starting at the second connector, and continued on. Care must be taken to insure that cables and connectors are not reversed, as this would short pin 26 (TERMPWR) to ground, and likely damage the drive or controller. Also, as explained earlier, the terminating resistors should remain only on the controller (Host Adapter) and the LAST drive on the cable, regardless of it's address. The Differential SCSI requires balanced lines, and is used mostly on high-end workstations.

HP Color LaserJet CP1510 Printer series- Models

2008-06-17T02:59:00.001-07:00

HP Color LaserJet CP1510 Printer series- Models

Printing system
Print technology	In-line colour laser printing technology
Print technology resolution	HP ImageREt 3600
Print quality (colour, best quality)	Up to 600 x 600 dpi
Print speed (colour, normal quality, A4)	Up to 8 ppm
Print speed (black, normal quality, A4)	Up to 12 ppm
First page out (black, A4)	< 25.5 sec (from "ready")
Processor type	Motorola Coldfire® V5x
Processor speed	450 MHz
Duty cycle (monthly, A4)	Up to 30000

Paper handling / media
Standard paper trays	2
Maximum number of paper trays	2
Media types supported	Paper (bond, brochure, colour, glossy, letterhead, photo, plain, preprinted, prepunched, recycled, rough), transparencies, labels, envelopes, cardstock
Standard input capacity (sheets)	Up to 150
Maximum input capacity (sheets)	Up to 150
Standard output capacity (sheets)	Up to 125
Maximum output capacity (sheets)	Up to 125
Recommended media weight	60 to 176 g/m² (up to 200 g/m² with HP Laser Cover papers, up to 220 g/m² with HP Color Laser Glossy Photo papers)
Paper handling	Single-sheet priority feed slot, 150-sheet input tray, 125-sheet face-down output bin
Duplex print options	Manual (driver support provided)
Standard media sizes	A4, A5, A6, B5 (ISO, JIS)
Custom media sizes	Priority feed slot, 150-sheet input tray: 76 x 127 to 216 x 356 mm

Memory / print languages / typefaces
Standard memory	96 MB
Maximum memory	352 MB
Memory slots	CP1515n: 1 144-pin DDR 2 DIMM slot CP1518ni: One 144-pin DDR 2 DIMM slot and SD, MMC, CF, XD, Memory Stick
Standard printer languages	HP PCL 6, HP Postscript level 3 emulation
Typefaces	80 scalable TrueType fonts

Connectivity
Standard connectivity	Hi-Speed USB (compatible with USB 2.0 specifications), 10/100Base-TX with RJ45 connector
Compatible network operating systems	Microsoft® Windows® 2000, XP Home, XP Professional, Server 2003; Windows Vista® Ready; Mac OS X v10.2.8, v 10.3, v10.4 or higher
Network interface	10/100Base-TX with RJ45 connector
Minimum system requirements	Microsoft® Windows® 2000, XP Home, XP Professional, Server 2003, Windows Vista® (32 and 64 Bit): 512 MB RAM, 350 MB hard disk space, CD-ROM drive, available USB port

Other technical information
Power consumption	CP1515n: 295 watts (active/printing), 11.4 watts (ready), 4.7 watts (sleep), 0 watts (off); Typical Electricity Consumption (TEC): 1.04 kWh/Week CP1518ni: 295 watts (active/printing), 12.2 watts (ready), 6.2 watts (sleep), 0 watts (off); Typical Electricity Consumption (TEC): 1.27 kWh/Week
Power requirements	Input voltage 110 to 127 VAC (+/- 10%), 60 Hz (+/- 3 Hz); 220 to 240 VAC (+/- 10%), 50 Hz (+/- 3 Hz)
Dimensions (W x D x H)	CP1518ni: 399 x 453 x 254 mm CP1515n: 399 x 453 x 254 mm
Weight	CP1518ni: 18.2 kg CP1515n: 18.2 kg
Recommended operating temperature range	20 to 27º C
Operating temperature range	15 to 32.5º C
Energy Star certified	Yes
Warranty	1 Year Limited Warranty (Return to HP/Dealer - Standard Bench Repair)

HP Color LaserJet CP1210 Printer series- Overview

2008-06-17T02:52:00.000-07:00

HP Color LaserJet CP1210 Printer series- Overview

Save space, save energy.

•	With new generation HP ColorSphere toner and HP ImageREt 2400, you get consistently vibrant and professional results right from the desktop. Innovative print technologies makes it possible to create high-quality in-house marketing documents.

•	Compact design and spave-saving, the printer also meets ENERGY STAR ® guidelines for energy efficiency. Intuitive control panel and front door design allow easy usage and maintenance.

•	Time To Completion (TTC)¹ is as fast as 52 secs with Instant-on technology from low power mode. In-line printing technology prints 4 colours in one pass for faster and smoother printing. Print speeds are up to 8/12 ppm for colour/mono.

SONY W Series - KLV-46W400A

2008-06-17T02:51:00.001-07:00

W Series - KLV-46W400A

Sony’s 46 (117cm) W-series BRAVIA features BRAVIA Engine 2 which incorporates full digital signal processing technology in all high-quality image processes, thereby maximizing the features of display devices and producing sharp, vibrant, life-like images.

SONY Television & Projector

2008-06-17T02:48:00.000-07:00

Sony has developed a myriad of Television and Projectors, as well as accessories, to cater to all types of lifestyle and business needs. Those seeking the latest in technology can look to our cutting edge LCD TVs, whereas conventional TV appreciators can pick from our range of CRTs that embody simplicity and functionality. If you wish to enjoy a home theatre experience, select from our Home Theatre Projectors or Projection TVs. We also have a line-up of Business Projectors to fit your purpose.

RAVIA™ LCD TV

View Model

The era of High Definition has arrived and Sony’s Bravia LCD TVs are here to help you fully enjoy its advantages. Innovation, creativity and technology come into play in the creation of our LCD TVs, bringing an unprecedented level of realism and stunning clarity to your movies, both visually and aurally. With slim and stylish designs, Bravia LCDs can fit anywhere in your home. Additional features like faster response time and PC connectivity help create the full entertainment experience.

INTEL

2008-06-17T02:46:00.000-07:00

processors

Intel® desktop processors deliver superb computing power, performance, and reliability at home and at work. Our notebook processors let you work and play in places you never thought possible. Our server and workstation processors provide enhanced scalability, power, and performance for robust multi-processing environments. And our embedded and communications processors combine outstanding performance with scalable, power-efficient processing for a wide range of embedded applications.

Intel in Consumer ElectronicsDiscover Intel's vision of how the Internet will converge with the TV experience. Explore emerging usage models, insights from industry experts, new Intel platform technologies and ecosystem solutions.

AMD Processor-In-a-Box

2008-06-17T02:45:00.000-07:00

Quad-core and triple-core performance
Phenomenal performance with advanced processor design. The AMD Phenom™ processors are the most advanced processors for true multitasking with true quad-core design. With an integrated memory controller and shared L3 cache, as well as fast HyperTransport™ 3.0 technology, AMD Phenom processors deliver virtually uninterrupted information flow between processor cores, main memory, and graphics and video accelerators for amazingly rapid system response and phenomenal system performance.

Want the ultimate PC processor for PC enthusiasts? A specialized server? A customized workstation? Perhaps you want industry-leading performance. Or to be ready for the 64-bit future. But most of all, do you want to design it, build it, and put it together yourself?

If you answered any of these questions “yes,” you want an AMD Processor-In-a-Box (PIB) or an AMD PIB without heatsink/fan (WOF).

Features and Benefits

Each AMD PIB/WOF comes with:

A high-performance AMD processor
AMD-qualified heatsink/fan with thermal interface (Not included in WOF)
Installation manual
AMD processor case sticker
Certificate of authenticity
3-year limited warranty