USB (Universal serial port): The USB has become the standard way to interface devices to a computer. Desingned to allow exterior peripherials to be attached using a standarized interface socket, this greatly improved the "plug-and-play" philosophy. By using "Hot-swapping", it allowed a multitude of devices to be connected and disconnected without the need of the computer being restarted. It also has the ability to give power to low-consumption devices without the requirement of an external power supply and also allows some devices to be used without requiring an individual device driver to be installed. However, it is not designed for exceedingly complex machines, and as stated previously, it can only provide power to small and power-efficent devices.
SCSI (Small computer system interface): A set standard for physically connecting and sending data between computers and exterior/peripheral devices, th SCSI defines everything from commands, to protocols, electrical and optical interfaces. It’s most common utilization is for tape and hard drives, however, it can also connect to a number of other peripherals, an example being a scanner, printer, or an optical drive enabled device (I.E. CD, DVD drives). It contains the definitions of cammands that specify certain peripheral drive types. The presence of a "unknown" one of these types suggestions, at least in theory, that it could be interfaced with any SCSI enabled device, however, the SCSI’s standard is mainly addresed toward commercial needs. They’re also not very popular in the buisness sense, SATA drives are more then adaqute and are much cheaper. Today SCSI is mainly used for high-powered work stations and servers.
Firewire: An Apple Incoroporated interface, it’s also known as the IEEE 1394 interface. It also goes by the name i.Link, which is what Sony has decided to dub it. It is now a personal computer serial bus interface industry standard. It offers high-speed communications capabilities, as well as isochronous real-time data service. It has now asserted itself into many of the applications that Parallel SCSI once reigned, thanks to it’s lower implementation prices and a less complex, more adaptable cabling system. Apple originally used it for their hugely popular iPod’s, but was replaced by USB connection in part to it’s space constraints and for the USB’s more universal compatibility.
Parallel interface: A type of plug-in that is normally found on a standard personal computer, it’s used in order to interface with a number of different external devices or peripherals. It also goes by the name "Centronics port" or "Printer port". It is defined by the IEEE 1284 standard, which is a bi-directional variation of the port. I most cases, the advent of the USB interface has made the parallel port obsolete, while other peripherals use the more complex Ethernet connection in place of the parallel port. Since 2006, a large number of personal computers now lack a parallel port, mostly as a cost-cutting measure. However, it is still used by laptops when they are operated at a docking station.
3 comments:
Hi Luc:
FYI--I'm still waiting for assignment #3 and #4...
This one:
Descriptions: 8/8
Three strengths for each: 11/12
only one advantage of Paralle given
Two weaknesses for each: 7/8
only one disadvantage for Firewire given
Late 3 days -30% (2 marks)
Overall: 24/28
Yaz
WIRELESS LOCAL AREA NETWORKS AND SECURITY
Wireless local area networks (WLANs) are popular at schools because they allow instructors and learner to remain connected to the network without being connected by wires.
However, security is a major concern. Using three different resources, research the security problems with WLANs.
Your results must include:
List and describe FOUR (4) security problems associated with WLANs. /4 marks
Describe at least one solution (or how the problem could be addressed if no solution is present) for each problem. /4 marks
Uses three different resources. /2 marks
TOTAL: /18 marks
Bibliography –
http://en.wikipedia.org/wiki/WLAN
http://compnetworking.about.com/cs/wirelessproducts/g/bldef_wlan.htm
WLANs (Wireless Local Area Network) are an easy way for Internet users to connect to the Internet without the need of physically connecting their computer into a network. While certainly a useful feature, especially in areas that have many Internet users who need to go do their business while staying connected to the Internet, there are a number of offsets that can make this technology troublesome. Not only is it taxing on an Internet server, (Wireless Internet takes up more bandwidth for less uploading and downloading speed) but also dangerous. Most WLANs are easy for a experienced hacker to hijack, allowing them to download illegal programs etc., copy credit card information that’s sent across the wireless, and send viruses to other users, all while remaining just another anonymous user on the wireless. It’s nearly impossible to track a hacker who’s using someone else’s wireless Internet, and many innocent people have been prosecuted for the illegal acquirement of programs when in reality it was a hacker who was “piggybacking” the wireless signal. However, there are a number of ways to protect your wireless Internet (Or from going on a dangerous wireless Internet). Here are four different problems, each with they’re own solution, or at least a way of minimizing the damage.
1) Illegitimate wireless access points- An extremely effective form of scamming, a skilled black hat (A hacker who does hacking for the sake of causing damage. There are also other categories of hackers known as white hats are known as hackers for the benefit of others, such as drivers that boost a computer’s power, and grey hats, who just generally mess around with program codes.) hijacks a computer network and then, using special software, routes it through his (Or her) computer. This creates a wireless Internet access point that originates from his computer. Usually set up in an area where there is normally pay-for-wireless-internet, the hacker creates his own payment form for any hapless Internet users who connect to his server. In order to access the Internet, the user enters their credit card information onto the form so that they can be billed, meanwhile obliviously sending it to the hacker as well. In a matter of minutes a black hat can spend thousands of dollars using the pirated credit card information. The only true way to avoid this is by never entering your credit card information on an unknown network. If you MUST get on the Internet, make sure to ask an employee who would know about their wireless Internet network and what the specifics of it are, so as to avoid any confusion in which are the legitimate Internet providers.
2) The spread spectrum – Many 802.11 wireless LAN protocol standards utilize the spread spectrum. This special modulation technique was created back in World War 2 in order to prevent the jamming of radio signals. Later (Much later technology wise) LANs began to appear, roughly around and in the 1990’s. Back then the Internet companies declared that the spread spectrum was top-of-the-line security for early adopters of wireless networks. The spread spectrum operates by “spreading” connection codes in a discreet way, technically making it impossible for an illegitimate user to access the wireless Internet if they didn’t know the access codes. The flaw with this supposedly flawless system was that 802.11 standards forces the code to be displayed publicly so that different companies would be able to communicate with each other. Because of this a any hacker with a 802.11-compliant radio NIC to be able to connect to the Internet, and because of this the spread spectrum is rendered nearly useless. While it is possible to disable the public code distribution, it isn’t particularly effective since every time you wanted the Internet to allow a new user to work on it, you have to give them the codes. This is not only a hassle, but also means one more mouth for the spectrum codes to be spread by.
3) WEP (Wireless Encryption Protection) – This old security fix encrypts each file that is sent through the wi-fi. This allows the user to send private e-mails, passwords, usernames, credit
On 802.11 networks, you can enable WEP (wired equivalent privacy), which encrypts the body of each frame. This is supposed to keep hackers from viewing sensitive e-mails, user names and passwords, proprietary documents, etc. As discussed in a previous tutorial, hackers can fairly easily decode WEP-encrypted information after monitoring an active network for less than one day.
Consequently, don't depend on WEP for protecting sensitive information. The use of WEP in most cases, nevertheless, is better than no encryption at all, especially if you deploy a mechanism to change the WEP key often (see related tutorial).
Max cast his gaze around the schools populace. It was break time, so almost everyone was outside eating lunch or in little, huddled groups chatting away amiably. He himself was sitting on a bench at the edge of the school grounds, waiting for his friends to show up at their usually meeting place. He had already unpacked his sandwich, a large Kaiser bun filled with a variety of meat, most uncooked. He proceeded to take a large bite out of it, a small trickle of blood from the raw steak crept down his chin from the corner of his mouth, like that of rain on a window. He rubbed his finger against the drip, catching it before it had a chance to fall and stain his jeans. He laid the partially eaten sandwich beside his lap on one of the few parts of the bench that wasn’t yet covered with grime and gum that had lost its flavor. He felt particularly hungry today, probably because his wolf side was reacting to the coming night’s full moon. He would have to make sure he had eaten lots of meat before the sun set and the moon took its place of dominance in the night sky, otherwise it would be another long night of abstaining from feeding on the inhabitants of the city.
While he personally wished that he could eat every full moon, he could understand why the pack didn’t allow such a practice. With their current numbers, if every werewolf in the city’s packs had one human every full moon, the strange number of deaths and disappearances on that specific time would surely be noticed. And the last thing that they wanted was to have the humans hunting them again. Instead, the packs now followed a strict schedule of which ones could eat. Each wolf was allowed only one human to feed on, and after they’re turn they would have to wait for four full cycles of the moon before they’re pack was allowed to feed again, and disobeying the pact meant that the guilty party would be severely reprimanded. The most common punishment was to have the wolf that was accused of early or excessive feeding to be locked in a cell an hour before the moon rose at each full moon, in order to keep them from going on a feeding frenzy.
It was best not to dwell on such things, though. He diverted his attention to his colleagues, trying to put names to the faces. He recognized Jill and Wren; both were Class 4 werewolves, able to change to their werewolf forms any day at night, but only within roughly a week of a full moon were they able to transform during the day. Werewolves like him were given a class, starting at 0 for a newly “initiated” one to 10 for those who had mastered control of their animalistic side. He himself was a class 5, and not only could he change any night and for about a week and a half after the full moon during daylight hours, he could also commit to a minor partial change, meaning he could raise one of his senses to the level of his werewolf form without actually having to go the whole 10 yards and completely transform to his wolf form. However, it was extremely taxing; doing it was somewhat like holding a powerful magnet to a metal plate, the closer you moved the magnet, the harder it was to keep it from pulling onto the plate. Boosting his senses like that put him closer to an actual physical transformation, therefore if he did it he had to constantly expend energy to keep himself from fully changing.
The others were close enough to see too, now. A smile creased his face when he saw Crista. They had been having a sort of teen crush with each other for the last few months, he still hadn’t told her about his second alter-ego nightlife, but maybe one day… He spotted the last of the party, Ash, being as small as she was, could hardly be seen when she was behind them. Her size, while not irregular, was still pretty petite. Normally when one became a werewolf, they would grow a fair bit larger, but she never ate a
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