Friday, September 11, 2009

Broadband technologies

Broadband Internet access, which widely called broadband is more faster and reliable than Dial-Up internet access.

There isn't a registered or accurate explenation for Broadband, the speed ranging up from 64 kbit/s up to 8 Mbit/s and more. the 2006 OECD report is typical by defining broadband as having download data transfer rates equal to or faster than 256 kbit/s, while the United States (US) Federal Communications Commission (FCC) as of 2009, defines "Basic Broadband" as data transmission speeds exceeding 768 kilobits per second (Kbps).

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.

"Broadband penetration" is now treated as a key economic indicator.

Although ISPs advertised about their bandwidth, customer/user can't get the actual bandwidth which ISP tells because of the overselling the bandwidth and the quality of the equipments.

Broadband technologies :

Mainly consists of DSL and Cable modems.
In some areas where DSL or Cable modems didn't available, there are wireless internet connecting options like Wi-Fi, HSDPA, EV-D0 and WiMax.

DSL ( Digital subscriber line )

Digital subscriber line, or DSL, is more expensive than dialup, but provides a faster

connection. DSL also uses telephone lines, but unlike dialup access, DSL provides a

continuous connection to the Internet. This connection option uses a special high-speed

modem that separates the DSL signal from the telephone signal and provides an Ethernet

connection to a host computer or LAN.

Digital Subscriber Line (DSL) technology is a modem technology that uses existing twisted-pair telephone lines to transport high-bandwidth data.

xDSL technologies

ADSL
SDSL
HDSL
HDSL-2
G.SHDL
IDSL
VDSL

xDSL is drawing significant attention from implementers and service providers because it promises to deliver high-bandwidth data rates to dispersed locations with relatively small changes to the existing telco infrastructure.

xDSL services are

dedicated
point-to-point

public network access over twisted-pair copper wire on the local loop (last mile) between a network service provider's (NSP) central office and the customer site, or on local loops created either intrabuilding or intracampus.

ADSL-Asymmetric Digital Subscriber Line

Allows more bandwidth downstream—from an NSP's central office to the customer site—than upstream from the subscriber to the central office. This asymmetry, combined with always-on access (which eliminates call setup)

Advantages:

Could use phone line and ADSL line at the same time
Could use to view videos, listen to songs, download files and for many purpose.
More than 6Mbps bandwidth available.
Continuous connection / Stable
can be purchased with various speed ranges and capabilities
Bandwidth is unlimited in some countries
can use existing phone line

Disadvantages:

Limited to 4Km radius from the nearest telephone exchange.
Have to buy a ADSL modem or router.
Expensive in some countries.
Not available in some areas
receiving data is faster than sending data

An ADSL circuit connects an ADSL modem on each end of a twisted-pair telephone line, creating three information channels:

a high-speed downstream channel
a medium-speed duplex channel
a basic telephone service channel

ADSL modems accommodate Asynchronous Transfer Mode (ATM) transport with variable rates and compensation for ATM overhead, as well as IP protocols.

ADSL uses two pieces of equipment, one on the customer end and one at the Internet service provider, telephone company or other provider of DSL services. At the customer's location there is a DSL transceiver, which may also provide other services. The DSL service provider has a DSL Access Multiplexer (DSLAM) to receive customer connections.

The DSLAM at the access provider is the equipment that really allows DSL to happen.

SDSL

Symmetric Digital Subscriber Line (SDSL) allows equal bandwidth downstream from an NSP's central office to the customer site as upstream from the subscriber to the central office.
SDSL supports data only on a single line and does not support analog calls.
The symmetry that SDSL offers, combined with always-on access (which eliminates call setup)
Because traffic is symmetrical, file transfer, web hosting, and distance-learning applications can effectively be implemented with SDSL.

HDSL

Originally developed by Bellcore, high bit-rate DSL (HDSL)/T1/E1 technologies have been standardized by ANSI (two-pair T1 transmission, with a data rate of 784 kbps on each twisted pair ) in the United States and by ETSI ( two-pair E1 system, with each pair carrying 1168 kbps, and a three-pair E1 system, with 784 kbps on each twisted pair ) in Europe.
T1 service can be installed by installing HDSL modems at each end of the line.
HDSL is heavily used in cellular telephone buildouts.
HDSL does have drawbacks. First, no provision exists for analog voice because it uses the voice band. Second, ADSL achieves better speeds than HDSL because ADSL's asymmetry deliberately keeps the crosstalk at one end of the line. Symmetric systems such as HDSL have crosstalk at both ends.

HDSL-2

HDSL-2 is an emerging standard and a promising alternative to HDSL. The intention is to offer a symmetric service at T1 speeds using a single-wire pair rather than two pairs.
The biggest advantage of HDSL-2, which was developed to serve as a standard by which different vendors' equipment could interoperate, is that it is designed not to interfere with other services. However, HDSL-2 is full rate only, offering services only at 1.5 Mbps.

ISDN Digital Subscriber Line

is a cross between ISDN and xDSL
Unlike ISDN, ISDL does not connect through the voice switch. A new piece of data communications equipment terminates the ISDL connection and shuts it off to a router or data switch.
This is a key feature because the overloading of central office voice switches by data users is a growing problem for telcos.
The limitation of ISDL is that the customer no longer has access to ISDN signaling or voice services. But for Internet service providers, who do not provide a public voice service, ISDL is an interesting way of using POTS dial service to offer higher-speed Internet access, targeting the embedded base of more than five million ISDN users as an initial market.

VDSL

transmits high-speed data over short reaches of twisted-pair copper telephone lines, with a range of speeds depending on actual line length.

The maximum downstream rate under consideration

51 and 55 Mbps over lines up to 1000 feet (300 m) in length.
13 Mbps over lengths beyond 4000 feet (1500 m) are also common.

ISDN ( Integrated Service Digital Network )

Integrated Service Digital Network (ISDN) is one of the oldest broadband digital access method which is a telephone data service standard.

A basic rate ISDN line is an ISDN line with 2 data "bearer" channels (DS0 - 64 kbit/s each). Using the ISDN bonding technology, we can get 256 kbps or more bandwidth.

Advantages :

Constant data rate at 64 kbit/s for each DS0 channel.
Two way broadband symmetric data transmission, unlike ADSL.
One of the data channels can be used for phone conversation without disturbing the data transmission through the other data channel.
Call setup is very quick.
Low latency
ISDN Voice clarity is unmatched by other phone services.
Caller ID is available.
Maximum distance from the central office is much greater than it is for DSL.
When using ISDN-BRI, there is the possibility of using the low-bandwidth 16 kbit/s "D" channel for packet data and for always on capabilities.

Disadvantages

ISDN offerings are dwindling in the marketplace due to the widespread use of faster and cheaper alternatives.
ISDN routers, terminal adapters ("modems"), and telephones are more expensive than ordinary POTS equipment, like dial-up modems.
ISDN provisioning can be complicated due to the great number of options available.
ISDN users must dial in to a provider that offers ISDN Internet service, which means that the call could be disconnected.
ISDN is billed as a phone line, to which is added the bill for Internet ISDN access.
"Always on" data connections are not available in all locations.
Some telephone companies charge unusual fees for ISDN, including call setup fees, per minute fees, and higher rates than normal for other services.

Satellite Internet

Is the most expensive way to use the Internet. But availability and bandwidth is greater than other technologies because Satellites can cover any place on the earth by using 3 separate satellites.

Advantages:

True global broadband Internet access availability
Mobile connection to the Internet
High bandwidth

Disadvantages:

High latency compared to other broadband services, especially 2-way satellite service
Unreliable: drop-outs are common during travel, inclement weather, and during sunspot activity .
The narrow-beam highly directional antenna must be accurately pointed to the satellite orbiting overhead
One-way satellite service requires a data uplink connection .
Satellite dishes are very large.

Cellular broadband / Wireless Internet

Cellular phone towers are very widespread, and as cellular networks move to third generation (3G) networks they can support fast data; using technologies such as EVDO, HSDPA and UMTS. These can give broadband access to the Internet, with a cell phone, with Cardbus, ExpressCard, or USB cellular modems, or with cellular broadband routers, which allow more than one computer to be connected to the Internet using one cellular connection.

Wi-fi and WiMax technology which provides mobility and connectivity as well as the more bandwidth than Dial-Up.

3G technology

A technology which used for mobile telephony, data, video, voice
speed differs from 384 kbps to 14.4 Mbps for downlink and till 5.8 Mbps for uplink.

HSDPA ( High-Speed Downlink Packet Access )

is a 3G technology
Downlink available from 1.8 Mbps , 3.6 Mbps, 7.2 Mbps and 14.4 Mbps.
Uplink till 5.8 Mbps

WiMax ( Worldwide Interoperability for Microwave Access )

a telecommunications technology that provides wireless transmission of data using a variety of transmission modes, from point- to-multipoint links to portable and fully mobile internet access
Provides speed up to 72 Mbps.
Based on IEEE 802.16 standard.

uses:

Connecting Wi-Fi hotspots to the Internet.
Providing a wireless alternative to cable and DSL for "last mile" broadband access.
Providing data and telecommunications services.
Providing a source of Internet connectivity as part of a business continuity plan.
Providing portable connectivity.

Wi-Fi

transmit at frequencies of 2.4 GHz or 5 GHz.The higher frequency allows the signal to carry more data.
use 802.11 networking standards, which come in several flavors (802.11a, 802.11b , 802.11g, 802.11n
allows local area networks (LANs) to be deployed without wires for client devices
High mobility
Security problems occurs

Advantages of wireless technologies:

more bandwidth than Dial-Up.
Mobility.
Availability.
Could use for media steaming, VoIP and many.
Easy to connect
Speed.

Disadvantages of wireless technologies:

Due to the 3G technology is a shared bandwidth service , bandwidth available from one tower could be shared among many users. So, it'll be slower than usual at sometimes.
Some service provider's shares single IP address among many users. So, it could make some problems with identity.
Service fees could be high.
Limited data bundle will be available to use. ( most service provider's don't provide unlimited data bundles )
Sometimes , it will have some issues with 3G connectivity although there is a tower nearby.
Security problems occurs because it hasn't security features by default.
Due to the radio signals, health problems could occur.

Now it's time to compare Dial-Up internet access with Broadband Internet access.

Differences between Dial-Up internet access and Broadband Internet access.

In Dialup we can use normal PSTN phone line to access to the Internet if there is a modem available. But we can't use normal PSTN phone line with a Modem or Router without configuring the telephone line for ADSL broadband.
Dial-Up internet technology is a lower speed with lower bandwidth and Broadband is not like that.
Dial-Up is suitable for light usage and broadband is suitable for heavy usage.
Dialup is a low cost method to access the Internet than broadband.
Dialup charges for Internet usage and for the time we used to surf the web because it make a call to connect to the Intenet and in Broadband it charges flat rate for a data bundle or for the time.
We can't make calls using the phone while browsing, but we can answer to the calls while browsing with broadband technologies.
Dialup can't use for VoIP and media streaming but broadband can.
When we use Dial-Up , there is a possibility to drop the connection more than Broadband.

Dial-Up can't used for mobile workers if there isn't a PSTN line. But some broadband technologies provide mobility.

Posted by K. W. Roshan Herath [ roshan herath ]

Source:

Broadband technologies

Broadband Internet Access

http://en.wikipedia.org/wiki/Broadband

http://en.wikipedia.org/wiki/Category:Broadband

accessed on 08^th September, 2009

Digital Subscriber Line

http://www.cisco.com/en/US/docs/internetworking/technology/handbook/DSL_Dig_Subscr_Ln.html

accessed on 08^th September, 2009

http://computer.howstuffworks.com/dsl.htm

accessed on 08^th September, 2009

Wireless technology

Internet connectivity mechanisms

Internet connectivity mechanisms

Now anybody can access the Internet and get it's benefit. There are several ways to connect to the Internet.

Dial-UP

ISDN

DSL

Cable connections

Wireless connections

T-1, T-2 and T-3 lines

Satellite

Dial-UP

Dialup is simply the application of the Public Switched Telephone Network (PSTN) to carry data on behalf of the end user. It involves a customer premises equipment (CPE) device sending the telephone switch a phone number to direct a connection to.
Speed ranges from 2400 bps to 56 Kbps
Twisted pair (regular phone lines) is the physical medium.
Cheap but slow compared with other technologies.
Speed may degrade due to the amount of line noise

ISDN

Integrated Services Digital Network is a telephone system network. ISDN is integrates speech and data on the same lines, adding features that were not available in the classic telephone system. access interfaces
- Basic Rate Interface (BRI)
- Primary Rate Interface (PRI)
- Broadband-ISDN (B-ISDN)

Dedicated telephone line and router required.
Speed ranges from 64 Kbps to 128 Kbps.
Physical medium is Twisted pair.
Not available everywhere but becoming more widespread.
An ISDN line costs slightly more than a regular telephone line, but you get 2 phone lines from it.
56K ISDN is much faster than a 56K dialup line

Digital subscriber line ( DSL )

Digital subscriber line ( DSL ) is more expensive than dialup, but provides a faster connection. DSL also uses telephone lines, but unlike dialup access, DSL provides a continuous connection to the Internet.
This connection option uses a special high-speed modem that separates the DSL signal from the telephone signal and provides an Ethernet connection to a host computer or LAN.
Doesn’t interfere with normal telephone use.
Bandwidth is dedicated, not shared as with cable.
Bandwidth is affected by the distance from the network hubs. Must be within 5 km (3.1 miles) of telephone company switch.
Limited availability.
Not networkable

Cable Internet

A cable Internet is a connection option offered by cable television service providers. The Internet signal is carried on the same coaxial cable that delivers cable television to homes and businesses.
A special cable modem separates the Internet signal from the other signals carried on the cable and provides an Ethernet connection to a host computer or LAN.
CMTS is the equipments provides the Cable Internet service to the users. It provides the same service which DSLAM offers.
512 Kbps to 20 Mbps
Coaxial cable and in some cases telephone lines used for upstream requests as physical medium

Wireless

Access is gained by connection to a high speed cellular like local multi-point communications system (LMCS) network via wireless transmitter/receiver.
Speed is 30 Mbps or more
Physical medium is Airwaves (antenna)
Can be used for high speed data, broadcast TV and wireless telephone service.

Satellite

Satellite connection is an option offered by satellite service providers.
The user's computer connects through Ethernet to a satellite modem that transmits radio signals to the nearest Point of Presence, or POP, within the satellite network.
Newer versions have two-way satellite access, removing need for phone line.
In older versions, the computer sends request for information to an ISP via normal phone dial-up communications and data is returned via high speed satellite to rooftop dish, which relays it to the computer via a decoder box.
Speed is 30 Mbps or more
Physical medium is Airwaves (antenna)
Bandwidth is not shared.
Satellite companies are set to join the fray soon which could lead to integrated TV and Internet service using the same equipment and WebTV like integrated services
Latency is typically high
Some connections require an existing Internet service account.

Frame Relay

Provides a type of "party line" connection to the Internet.
Requires a FRAD (Frame Relay Access Device) similar to a modem, or a DSU/CSU.
speed ranges from 56 Kbps to 1.544 Mbps (or more, depending on connection type)
Various physical mediums used
May cost less than ISDN in some locations.
Limited availability.
Uses one of the connection types below, fractional up to OC3

Fractional T1 (Flexible DS1)

Only a portion of the 23 channels available in a T1 line is actually used.
Speed ranges from 64 Kbps to 1.544 Mbps
Physical medium is Twisted-pair or coaxial cable
Cheaper than a full T1 line with growth options of 56 Kbps or 64 Kbps increments as required.

Special lines and equipment (DSU/CSU and router) required.
Speed 1.544 Mbps
Physical medium is Twisted-pair, coaxial cable, or optical fiber
Typically used for high bandwidth demands such as videoconferencing and heavy graphic file transfers.
Minimum for large businesses and ISPs.
Expensive

Typically used for ISP to Internet infrastructure.
Speed 44.736 Mbps
Physical medium is Optical fiber

OC-1

Typically used for ISP to Internet infrastructure within Internet infrastructure.
Speed 51.84 Mbps
Physical medium is Optical fiber

OC-3

Typically used for large company backbone or Internet backbone.
Speed 155.52 Mbps
Physical medium is Optical fiber

The history of the Internet in brief

Here is the brief history of the Internet:

ARPA (1957)

There is a competition between USSR and USA for technology and USSR won it by launching Sputnik. Then USA launched the Advanced Research Projects Agency (ARPA) under the auspices the Department of Defense. Launching the ARPA is mainly focused to maintain a technological lead, particularly with regards to the military.

Packet Switching (1968)

USA wanted to expand the ARPA project to make it reliable at any time. Then the invented packet switching. National Physical Laboratory created the first packet switching network in 1968.

ARPANET (1969)

ARPA created ARPANET in 1969 to help ARPA-funded researchers collaborate more effectively for non profit uses like education and researches which were based on the packet switching technology built at the Rand Corporation in the early 1960s. The first ARPANET were positioned at UCLA, Stanford Research Institute, University of California at Santa Barbara, and University of Utah in Salt Lake City.

TCP/IP (1983)

Between 1969 and 1983, a variety of individual networks sprouted and grew. (BITNET,CSNET). Connecting each of these independent networks was difficult, though, because they didn't use the same protocols and therefore couldn't exchange information.

As a result, ARPA commissioned the development of a new protocol called Transmission Control Protocol/Internet Protocol (TCP/IP) that would allow different networks to connect.

Most networks had changed to TCP/IP in the late 1970s, but ARPANET didn't make the change until January 1, 1983. Thus, many folks consider that date as the birthday of the Internet.

NSF Creates NSFNET (1986)

In 1986 the National Science Foundation created NSFNET, an Internet backbone with a speed of 56K. This backbone connected five super-computing centers located at Princeton, Pittsburgh, UCSD, UIUC, and Cornell. NSFNET precipitated a large number of connections from various universities.

NSFNET has been updated continually since 1986. In 1988, two years after going online, the backbone was upgraded to T1 (1.544M). In 1991, it was upgraded to T3 (44.736M)

ARPANET Is Dismantled (1990)

Newer networks connected the sites that ARPANET connected, and thus ARPANET was no longer useful.

The World Wide Web (1992)

Tim Berners-Lee, a physicist at CERN in Switzerland, invented the World Wide Web (Web) in 1992 as a way to organize information in a more brain-like fashion. His idea was to allow people to make multiple free associations with different bits of information.

NSF Establishes InterNIC (1993)

NSF created InterNIC, a group of businesses that provide a variety of essential services to the Internet.

The Internet Today

The growth of the Internet has been explosive. In 1985, there were about 2,000 host computers on the Internet. Now there are millions of host computers and many more millions of actual users. Now Internet isn't limited to educational and research purpose but also in too many fields like commercial and welfare services and etc.

Tuesday, September 8, 2009

Note to new Linux users: No antivirus needed

Savvy Windows users have to watch their virus checkers as closely as the head nurse in the ICU keeps an eye on patient monitors. Often, the buzz in the Windows security world is about which protection-for-profit firm was the first to discover and offer protection for the malware du jour -- or should I say malware de l'heure? The only thing better than having backed the winning Super Bowl team come Monday morning at the office coffeepot is having the virus checker you use be the one winning the malware sweepstakes that weekend.

If a rogue program finds a crack in your Windows armor, paying $200 per infection to have your machine scrubbed and sanitized by the local goon^H^H^H^H geek squad not only helps to reinforce the notion that you have to have malware protection, but that it has to be the right protection, too. The malware firms are aware of this, and all of their advertising plays upon the insecurity fears of Windows users and the paranoia that results. Chronic exposure and vulnerability to malware has conditioned Windows users to accept this security tax.

It's no wonder, then, that when Windows users are finally able to break their chains and experience freedom on a Linux desktop, they stare at me in disbelief when I tell them to lay that burden down. They are reluctant to stop totin' that load. They have come to expect to pay a toll for a modicum of security.

I try to explain that permissions on Linux make such tribute unnecessary. Without quibbling over the definitions of viruses and trojans, I tell them that neither can execute on your machine unless you explicitly give them permission to do so.

Permissions on Linux are universal. They cover three things you can do with files: read, write, and execute. Not only that, they come in three levels: for the root user, for the individual user who is signed in, and for the rest of the world. Typically, software that can impact the system as a whole requires root privileges to run.

Microsoft designed Windows to enable outsiders to execute software on your system. The company justifies that design by saying it enriches the user experience if a Web site can do "cool" things on your desktop. It should be clear by now that the only people being enriched by that design decision are those who make a buck providing additional security or repairing the damage to systems caused by it.

Malware in Windows Land is usually spread by email clients, browser bits, or IM clients, which graciously accept the poisoned fruit from others, then neatly deposit it on their masters' systems, where malware authors know it will likely be executed and do their bidding -- without ever asking permission.

Some malware programs require that you open an attachment. Others don't even require that user error. By hook or by crook, malware on Windows often gets executed, infecting the local system first, then spreading itself to others. What a terrible neighborhood. I'm glad I don't live there.

On Linux, there is built-in protection against such craft. Newly deposited files from your email client or Web browser are not given execute privileges. Cleverly renaming executable files as something else doesn't matter, because Linux and its applications don't depend on file extensions to identify the properties of a file, so they won't mistakenly execute malware as they interact with it.

Whether newcomers grok permissions or not, I try to explain the bottom line to them: that because they have chosen Linux, they are now free of having to pay either a security tax up front to protect themselves from malware, or one after the fact to have their systems sterilized after having been infected.

So Linux is bulletproof? No. Bulletproof is one of the last stages of drunkenness, not a state of security. Linux users, like users on every operating system, must always be aware of security issues. They must act intelligently to keep their systems safe and secure. They should not run programs with root privileges when they are not required, and they should apply security patches regularly.

Misleading claims and false advertising by virus protection rackets to the contrary, you simply don't need antivirus products to keep your Linux box free of malware.

Source: By Joe Barr, Monday, 26 February 2007 08:00 Linux.com

http://www.linux.com/news/software/applications/8261-note-to-new-linux-users-no-antivirus-needed

posted by K.W. Roshan Herath

Group of Microsoft Rivals Nears Patent Deal in Bid to Protect Linux

Microsoft Corp. has suggested in recent years that companies using the Linux computer-operating system might be violating Microsoft patents. Now, in an effort to avert any legal threat that might discourage the adoption of Linux, a group of Microsoft rivals is about to acquire a set of patents formerly owned by the software giant.

Linux is a free open-source operating system that has gained ground against Microsoft's Windows software among business users, especially in servers, the big back-office computers inside companies. Linux's fans say the free software is more secure than Windows and, because its blueprint is open to users, can be more easily customized.

The group, which includes major corporate supporters of such open-source software -- including International Business Machines Corp., Red Hat Inc. and Sony Corp. -- said it is nearing an agreement to acquire 22 patents that Microsoft sold to another organization earlier this year. Though the issue hasn't been tested in court, the patents may relate to Linux.

The group, the Open Invention Network, argues that its acquisition will protect users of Linux software from expensive lawsuits that could result if the patents fell into the hands of "patent trolls," groups that don't typically make products and exist primarily to earn money from lawsuits and settlements in patent cases.

The group said it is close to signing a deal to acquire the patents from Allied Security Trust. AST buys patents to protect its members from patent litigation, provides them with licenses to the technology, and then resells the patents on the open market. OIN and AST, whose members include Verizon Communications Inc., Cisco Systems Inc. and Hewlett-Packard Co., could announce an agreement as early as this week.

AST won control of the patents in a private auction held by Microsoft. OIN and AST said their cooperation ensures that the Microsoft patents won't end up with patent trolls, leaving some big boosters of Linux potentially exposed. "We have averted a scenario where these patents can be used for negative purposes," said Keith Bergelt, chief executive officer of OIN, which holds on to its patents and broadly licenses them.

Financial terms of the deals aren't being disclosed.

Mr. Bergelt said Microsoft presented the patents to potential bidders in its auction as relating to Linux. A Microsoft executive declined to say how the company described the patents to bidders.

Microsoft's sale of the patents is a new twist in its approach to Linux. Microsoft executives have previously said that the company holds more than 200 patents, out of the company's total portfolio of more than 50,000 patents, that they believe are violated by Linux software. In recent years, Microsoft has entered into patent-licensing pacts with dozens of companies that distribute or use open-source software in their products.

Earlier this year, Microsoft went a step further and filed a lawsuit in federal court in Seattle against the Dutch GPS device maker TomTom NV for allegedly violating Microsoft patents related to Linux, which were used in TomTom navigation products.

That suit, Microsoft's first Linux-related action and its first-ever alleging infringement of a software patent -- caused a stir among open-source advocates who feared Microsoft might be mounting a major legal offensive against Linux users. Microsoft and TomTom subsequently settled the suit for undisclosed terms.

Dave Kaefer, general manager for intellectual-property licensing at Microsoft, disputed allegations by some open-source advocates that the company intended to disrupt the market for Linux products with the sale of the patents, arguing that it wouldn't have sold the patents to AST, a firm whose members also include Linux boosters, if its goal had been disruption.

Mr. Kaefer said the patents, acquired from Silicon Graphics, were sold because they weren't strategic to the company. "They weren't important to our business going forward," he said.

Source:
By NICK WINGFIELD
http://online.wsj.com/article/SB125236988735891147.html?mod=googlenews_wsj
[ accessed on 08th Sep, 2009 ] by K.W.Roshan Herath

Tuesday, September 1, 2009

How to mount an .iso image on Linux

How to mount an .iso image on Linux

When we use CD/DVD images to burn into a CD/DVD, normally we can't see the files which included inside the CD/DVD without burning them into a CD/DVD. IF you use Linux
Operating System, you never need to burn the .iso file into a CD/DVD to see the files inside the .iso image file.

At first you must have the root user. You can simply do it by typing su on basic linux terminal window ( if you use *buntu system you can type sudo instead of su ) and providing the correct password. Then the prompt will change to the root user.
Then make a directory in /media folder to mount iso files. ( in most linux distros /media is the place which mount CD/DVD. )

Syntax : mkdir /media/folder_name
folder_name should be the name of the folder which used to mount iso files.

Then mount the CD/DVD iso images into the folder which we created before.

Syntax : mount image_file path_to_the_folder -t iso9660 -o loop

image_file is the name of the iso file with the path and .iso extention
path_to_the_folder is the place of the folder which we created
before.

Now you can open the the .iso file as a normal CD/DVD inside the Drive.
To unmount the image file from the location use

umount /media/folder_name

posted by K.W.Roshan Herath [ roshanherath ]