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Computer Networking
Computer networks are collections of computers which are connected together in order to communicate and transfer information. Questions about computer networks, networking protocols, and how to set them up belong here.
18,810 Questions
Do you have to pay monthly with a wireless router?
no you don't. You only have to pay for the broadband internet. The actual wireless router is a one time fee.
You should purchase your router and not rent it, but both options are available with many internet service providers. You can also purchase and add the router yourself once you have Internet Service
What is digital transmission of analog data?
it means that you digitize analog data for transmission . Like 2 computer that chatting .
Using command prompt how do you find your ip address?
Answer In the Windows command prompt, type "ipconfig". That will list basic information, including your IP address, of all your network interfaces. Be warned this will only return you your local IP address. That means if you're on a LAN, then you'll get the IP address of that network and not your WAN IP address.
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Note: It is "ifconfig" on a Linux operating system.
What is the difference between data communication and telecommunication ?
What is the voltage of a cat5 cable while it's communicating?
One person has suggested: "Its a very small amout of voltage. Usually microvolts." This is somewhat inaccurate, but only by a factor of around 1,000,000 times too small. A more accurate number is: "around 2.5 volts peak differential". Your typical consumer LAN uses 10Base-T signalling over a Category 3, 4 or 5 twisted-pair cable. The 10BASE-T transmitter output voltage specified in the standard (IEEE 802.3-2005 14.3.1.2.1) requires a peak differential voltage of 2.2 to 2.8 V into a 100-Ohm resistive load. There are IEEE technical discussions (March 2007) about reducing it to below 2 volts, perhaps using a "negotiation" protocol for devices on the LAN to choose a lower voltage if they are capable.
Yes. See below article from binarylotus:
With the release of Mario Kart DS, Nintendo has entered the online gaming arena. Unfortunately, while the NDS does have (some) 802.11b support, it does not feature WPA support (only lower strength security WEP is supported). While Nintendo does offer a Wi-Fi USB adapter that can remedy this problem, you may be able to get by without it. This article might save you a cool $40.
Scenario: You have an existing wireless network, but you have to (or better yet, want to) use WPA, WPA2, or something other than WEP for your encryption standard. Or, you don't have an existing wireless network. Nintendo's official solution is to buy their USB Wi-Fi adapter, but this solution requires you to use Windows XP or Vista. Mac and other users are totally out of luck at this time. However, if you've already got a Wi-Fi adapter of some kind (or if you're like me, can find a generic adapter for cheap - some are out for as low as $10 after rebate nowadays), you may not need to buy the adapter. You'll need the following: * A computer (safe to say you likely have one of these if you're reading this) * A wireless network adapter that supports the 802.11b protocol (b+g is fine) * A secondary network adapter that connects to your ISP (either directly, or through your network). This can be a wireless or a wired adapter. * A broadband internet connection (required by Nintendo Wi-Fi) For the purposes of this article, I'll be using the Hawking Technology HWU54G adapter (ver 2), but many other adapters should work. Be warned though, that not all adapters will support the methods listed here. Also, I'll be detailing the procedure on Windows XP, but the general procedure should work on other OS' as well. The important part is your adapter's value add software features. Step One: First we need to install the Wi-Fi adapter (if it isn't already). If you're using a PCI adapter, power off the machine, and install the card into your computer. If you're using a PCMCIA/PCCard (laptops) or USB adapter, install the drivers and software, then connect the adapter. In case of doubt, consult the manual. Optional pre-setup step: If you can, get a copy of NetStumbler and find out what wireless channels and SSIDs are in use in your area. Make note of them for later. Provided you have your adapter installed, NetStumbler should work fine. Close NetStumbler when you're done. Step Two: After you have everything installed and ready to be configured, load up the manufactuer supplied configuration utility for your Wi-Fi adapter. You may be prompted by Windows to let it handle the adapter; do NOT allow this! Use the provided utility that comes with your adapter. Currently, the Windows Wireless Zero Configuration utility (or in other words, the built-in Wi-Fi capabilities of Windows) doesn't work for what we want to do (or at least, I haven't been able to get it to work). Step Three: We need to make the adapter act like an access point that the NDS can connect to first of all. Look for an option to have the adapter set itself as an access point (or use ad hoc mode). The Hawking adapter uses the ZyDAS chipset and configuration utility and supports this functionality. Step Four: Now that your adapter is set in access point (or ad hoc) mode, it's time to configure the settings. For the ZyDAS config Here the "More Setting…" button has been selected and the next menu has popped up. We need to set the SSID (System Set ID) most importantly of all, and those of you with adapters that feature "turbo" modes (ie, those that advertise speeds of 108mbps) will need to turn that feature off. Select the "Change" button, and enter the SSID you want to use. If you used NetStumbler earlier to find out what SSIDs and channels are being used, change your WiFi channel to one that's not being used if possible; otherwise, select the one with the least amount of SSIDs. Also, do not use the same SSID as another that you've found. If you have a setting for power use, it's recommended you keep it at maximum for now. Step Five: The next step is to set up some security measures. The first of these is WEP encryption. Again, the DS does not support WPA, WPA2, or other methods; this is as good as it gets. In any case, either "Shared Key" (better) or "Open System" should work, so select one of those. WEP is the default here, but may not be for your adapter; select it (if you have the choice of key length, stick with 64 bits). Now comes the fun part. For the ZyDAS utility, select "Setting", then "Change" in the new window that appears. The trick here is that you need to make a key value (password) out of numbers (zero through nine), and the letters A through F, and the key value has to be 10 characters long. If you have an option to use hex or ASCII characters (as seen above), stick with hex. If you have four fields as shown here, enter the same key value for each (the NDS only uses the first key value anyway). If you have a selection as to what key value to use or default to, stick to #1. Step Six: We're getting there, don't worry. With WEP enabled, we have an access point of sorts that we could connect the DS to…but at this point, it's not connected to our internet connection. We need an option to connect the adapter to the other adapter in the system that is, and that's achieved by bridging (that is, making a connection between the adapters). With the ZyDAS driver, this is done by setting the "Bridge Adapter" box to the ethernet adapter present in my system. If your utility doesn't offer this functionality, you may still be able to have Windows bridge the adapters for you. Open up network properties, select the "access point" and your main connection, then select Advanced -> Bridge Connections. This will establish a link between the access point we've set up and your main internet/network connection. Note: in the interest of security, it's recommended that you disable the access point when it's not in use. Step Seven: Let's play! Fire up Mario Kart DS or other game that uses the NDS Wi-Fi feature. Enter settings, then search for an access point. You should see the SSID you gave to your access point in step four; select that. You will then be prompted for your WEP key; enter that. The program will then test the connection. If successful, you're ready to go! Step Eight: Optional, but recommended to shore up security. Your DS, like most other network adapters, has a unique (hopefully) identifying code, called a MAC address. As seen in the second screenshot, some utilities have a MAC address filter you can use to tell the adapter to only accept connections from certain MAC addresses. First, we need to get your NDS' MAC address. Go back into the Wi-Fi setup program. Select the option to view system settings. Record the MAC address. Now, set your access point to only accept connections from MAC addresses you enter, and type in the address to have it accepted by the access point. Step Nine: As step eight, optional, and can shore up security. SSIDs are normally broadcast to allow others to find them, but this can lead to people snooping on them. You can turn this option off in most utilities. Since you've already connected and saved the settings, this shouldn't present problems. All in all, the big problems you'll face are not necessarily that you can't do the steps required here, it's that the utility/value add software that comes with your adapter may not be up to snuff. There's no guarantee that this will work with every adapter either. Hopefully sometime there will be a way to configure this with only the native utilities and functionality in the OS, but at the present time, that doesn't seem likely to happen. In any case, good luck, and happy online gaming! * The downloaded driver for the Hawking adapter has a broken version of their utility; use their CD install (if you must have the newer driver installed, uninstall everything, install the new driver, pull out the files from the InsTemp_USB dir, uninstall that driver, install the old one, then do a driver update from Device Manager. Manually point to where you stashed the new driver files, and point the wizard to that directory. * The Hawking adapter gets quite warm during operation; you may want to try turning down the power setting. This may also be useful for notebook users needing to conserve power. * Because the Nintendo Wi-Fi adapter is essentially a rebadged Buffalo WLI-U2-KG54-AI, I expect this product to work as well, but again, no guarantees. The advantage the Nintendo version has is specific software support. * You may need to turn off the Windows firewall off on your adapter, if it is turned on (WinXP SP2 users should be especially mindful of this). * When in ad hoc mode, your access point will only go up to 11mbps. You can have multiple DS' connected to your access point, but the limit will be around 5 or so units, as each DS takes around 2mb of bandwidth each (at least, reportedly this is the case; the Nintendo adapter accepts only five connections). * You can use a 128 bit key instead of the 64 bit key used above - simply select 128 bit in the adapter utility, and enter a 26 character long key value instead of a 10 character long one. The DS supports up to a 152 bit key (or 32 characters), so a 256 bit key won't work. * This document was partially inspired by a guide written by "Darkwind_776″ over on the Nintendo forums. His guide was written for the Gigabyte RT2500. * Recently I purchased a CompUSA 54g Wireless LAN USB adapter model (SKU: 333626) which came out to $3 after rebates. It uses a very similar ZyDAS utility and can be configured the same way.
What is the difference between SLIP and PPP?
SLIP is called Serial Line Internet Protocol and PPP is the acronym of Point-to-Point Protocol.
Multi-ProtocolsPPP has some additional benefits. Unlike SLIP (which can only transport TCP/IP traffic), PPP is a multi-protocol transport mechanism. This means that PPP not only transports TCP/IP traffic, but can also transport IPX and Appletalk traffic, to name just a few. Better yet, PPP lets you transport all of these protocols at the same time - on the same connection.This is often not a concern for most users since their purpose of either using SLIP or PPP is to connect to the internet and the internet uses TCP/IP only. Therefore, there is no need to transport other protocols.
Configuration NegotiationWith SLIP, you have to know the IP address assigned to you by your service provider. You also need to know the IP address of the remote system you will be dialing into. If IP addresses are dynamically assigned (depends on your service provider), your SLIP software needs to be able to pick up the IP assignments automatically failing which you have to setup them up manually. You may also need to configure such details as MTU (maximum transmission unit), MRU (maximum receive unit), use of VJ compression header (ie., CSLIP), etc. All these can get confusing pretty fast.PPP addresses this problem by negotiating configuration parameters at the start of the connection. This can greatly simplify the configuration of your PPP connection.
Automatic LoginMost SLIP/PPP software can dial-up and automatically login for you. However, they often depend on your service provider's system sending out standard prompts (eg, "login:" to get the login name and "password:" to get the password). If they are any way non-standard, you either need to write a script to automate the login process yourself or login manually in the terminal emulation mode of your SLIP/PPP software.PPP provides two methods with which logins can be automated - PAP (Password Authentication Protocol) and CHAP (Challenge-Handshake Authentication Protocol). Both provide the means for your system to automatically send your login userid/password information to the remote system.
A general-purpose machine that processes data according to a set of instructions that are stored internally either temporarily or permanently. The computer and all equipment attached to it are called hardware. The instructions that tell it what to do are called "software." A set of instructions that perform a particular task is called a "program" or "software program."
What a Computer Does
The instructions in the program direct the computer to input, process and output as follows:
Input/Output
The computer can selectively retrieve data into its main memory (RAM) from any peripheral device (terminal, disk, tape, etc.) connected to it. After processing the data internally, the computer can send a copy of the results from its memory out to any peripheral device. The more memory it has, the more programs and data it can work with at the same time.
Storage
By outputting data onto a magnetic disk or tape, the computer is able to store data permanently and retrieve it when required. A system's size is based on how much disk storage it has. The more disk, the more data are immediately available.
Processing (The 3 C's)
The computer performs all processing by "calculating," "comparing" and "copying" the data stored in its memory (RAM).
Calculate
The computer can perform any mathematical operation on data by adding, subtracting, multiplying and dividing one set with another.
Compare
The computer can analyze and evaluate data by matching it with sets of known data that are included in the program or called in from storage.
Copy
The computer can move data around to create any kind of report or listing in any order.
Calculate, Compare and Copy
By calculating, comparing and copying, the computer accomplishes all forms of data processing. For example, records are sorted into a new order by comparing two records at a time and copying the record with the lower value in front of the one with the higher value.
The computer finds one customer out of thousands by comparing the requested account number to each record in the file. The query statement: SUM SALARY FOR TITLE = "NURSE" causes the computer to compare the title field in each record for NURSE and then add (calculate) the salary field for each match.
In word processing, inserting and deleting text is accomplished by copying characters from one place to another.
Remember The 3 C's
If you wonder whether the computer can solve a problem, identify your data on paper. If it can be calculated, compared and copied on paper, it can be processed in the computer.
The 3 C's - Finding Things This example counts all California records in the database by comparing each record with "CA." Every record in the database is read into memory. The memory locations that state is written into are compared with the letters "CA" in the program. If they are equal, a "1" is added to the California counter. The second record is written into the same memory bytes as the first record, and the field is compared again. This process is performed until the last record has been examined. The 3 C's - Displaying and Printing Data are stored as contiguous fields in the database with no blanks in between. The data are displayed and printed the way we like to see it by writing the data into memory and copying the characters into the desired order. The date in this example is printed through a "picture," which is a set of characters that acts as a filter. Each character in the date is compared to a corresponding character in the picture, and the one copied as output is determined by the rules. Pictures can be implemented in software or in hardware. The 3 C's - Sorting Sorting (resequencing) data is accomplished by comparing each item of data with the others and copying it into the appropriate order. Of course, there is a ton of calculating going on to keep track of what is being compared. Years ago, when databases were stored on tape, the speed of a vendor's sort program was a powerful marketing feature. All transactions had to be sorted into account number sequence in order to be processed. In today's online systems, data are often indexed. Instead of sorting the actual data records themselves, the much smaller indexes are sorted. The 3 C's - Editing The magic of word processing is nothing more than copying text. In this example, in order for the "O" to be inserted into the word, the remaining characters are copied one memory location (byte) to the right to make room for it. Deleting is copying in reverse. As in all data processing, there is a whole lot of calculating and comparing going on to keep track of where the text is stored in memory.The Stored Program Concept
The computer's ability to call in instructions and follow them is known as the "stored program concept." Instructions are copied into memory from a disk, tape or other source before any data can be processed. The computer is directed to start with the first instruction in the program. It copies the instruction from memory into its control unit circuit and matches it against its built-in set of instructions. If the instruction is valid, the processor carries it out. If not, the computer comes to an abnormal end (see http://www.answers.com/topic/crash-16).
The computer executes instructions sequentially until it finds a GOTO instruction that tells it to go to a different place in the program. It can execute billions of instructions per second, using the same program logic on each new set of data brought in.
Operations Overlap
Input/output and processing are made to overlap. While one program is waiting for input from one user, the operating system (master control program) directs the computer to process data in another program. Large computers allow many input/output operations to occur simultaneously with processing.
It can take hundreds of thousands of discrete machine steps to perform very routine tasks. Your computer could easily execute several million instructions to put a requested record on screen for you.
Computer Generations
First-generation computers, starting with the UNIVAC I in 1951, used vacuum tubes, and their memories were made of thin tubes of liquid mercury and magnetic drums.
Second-generation systems in the late 1950s replaced tubes with transistors and used magnetic cores for memories (IBM 1401, Honeywell 800). Size was reduced and reliability was significantly improved.
Third-generation computers, beginning in the mid-1960s, used the first integrated circuits (IBM 360, CDC 6400) and the first operating systems and DBMSs. Online systems were widely developed, although most processing was still batch oriented using punch cards and magnetic tapes.
Starting in the mid-1970s, the fourth generation brought us computers made entirely of chips. It spawned the microprocessor and personal computer. It introduced distributed processing and office automation. Query languages, report writers and spreadsheets put large numbers of people in touch with the computer for the first time. Even with the hundreds of millions of people using computers every day, we are still in the fourth generation. Some skill is still required to use the computer even if only to surf the Web and send e-mail.
The fifth generation implies faster hardware and more sophisticated software that uses artificial intelligence (AI) routinely. Natural language recognition is a major component of the fifth generation. When you can have a reasonably intelligent conversation with the average computer, you will be in the fifth generation, perhaps in the 2015-2020 time frame.
The Beginning of Commercial Computing In the early 1950s, the UNIVAC I ushered in the computer age. This picture was taken in Frankfurt, Germany in 1956 and shows the console on the right, a little more than half the CPU on the left and the tape drives in the background. The Installation This picture, taken in 1956, shows half the CPU of the UNIVAC I. Imagine yourself watching this awesome sight and someone says to you, "in 20 years, everything you see being wheeled up the ramp will fit on the tip of your finger." Would you have believed it?Types of Computers
Computers can be as small as a chip or as large as a truck. The difference is in the amount of work they do within the same time frame. Its power is based on many factors, including word size and the speed of its CPU, memory and peripherals. Following is a "rough" guide to system cost.
Type of Approximate Cost Computer In 2006 US $ Chips Microcontroller (MCU) (4, 8, 32, 16-bit) $1 - $150 Microprocessor chip (4, 8, 16, 32, 64-bit) $5 - $1K Client Systems Desktop/laptop client (32, 64-bit) $400 - $6K Workstation (32, 64-bit) $5K - $25K Server Systems Low end server (32, 64-bit) $2K - 5K Midrange server (32, 64-bit) $15K - 250K High-end server/mainframe (32, 64-bit) $500K - $3M Supercomputer (64-bit) $1M - $5M K = thousand $ M = million $Network coverage is coast to coast coverage and date roaming. It is something that you pay for monthly and you get so much depending on how much you pay monthly.
How does capacitance cause signal degradation?
A capacitor is composed of two conductors that are separated by an insulator. This is a simple definition, but it says a lot about capacitance, and it says it very well. By this definition, there could be capacitance just about anywhere in a power system or circuit. Yes! There could! And there is! Capacitance offers "resistance" to alternating current (AC) signals called reactance. The higher the frequency, the less reactance there is and the better the signal will be able to pass through the capacitor. In modern electronic equipment, there are lots of circuit pathways and lots of components in the circuits. This leads to a lot of distributed capacitance in the circuit. This distributed capacitance represents a lot of little pathways for signals to "jump gaps" in the circuit. Signals will avoid going through the components and devices and also avoid following all the pathways it is supposed to follow. The signals will be "shorted around" components or "shorted to ground" in other pathways. This combines to effect signal loss or degradation. The higher the frequency of the signal put through a circuit, the more loss there will be to the signal due to distributed capacitance.
Can i use more than one browser in your computer and if I use then do have i any problem?
More than one Internet Browser can be used & it doesn't have any problem on the system unless any bugs are there in Browser application.
Can you mix single-ended and differential devices on a SCSI subsystem Why or why not?
when differential signaling was first introduced you could not mix se and hvd devices because of the high voltage used in the hvd. since then a new signaling called lvd is used and it will allow you to use a se if you use the lvd/se mode.( p.1008 managing and maintaining your PC 5th edition)
How do I recover sound back on my formatted system?
Recover my files is a good file recovery program (Note: there are free programs)
try searching for "File recovery"
5 List three functions performed by the power supply?
Manages watts to each device
Manages volts to each device
Supplys power to multipul devices
What is Difference between static and dynamic routing tables?
Technically, there is no such thing.
The routing table has several entries (think of them as lines); the individual LINES in the routing table can be static or dynamic; and the routing table in its entirety can have both types.
A static entry is programmed (hard-coded) by a network administrator.
A dynamic entry is one which the router learns from a routing protocol, such as RIP, EIGRP, OSPF, BGP, etc. The routers "talk" to one another, and tell one another that they have routes to certain networks; the router that receives such updates will update its routing table as a result. Such entries are temporary, and expire after a relatively short time.
On a psp what do you do if it says trying to obtain ip address?
nothing, that means it's trying to connect to the internet.
If you are refering to port 21 (networking) then it is the port used by the FTP process (File Transfer Protocol).
The person may be referring to AspenTech ip.21 which is a process control historian. See related link.
Different types of network cables, such as coaxial cable, optical fiber cable, and twisted pair cables, are used depending on the network's physical layer, topology, and size. The devices can be separated by a few meters (e.g. via Ethernet) or nearly unlimited distances (e.g. via the interconnections of the Internet). Cables are used in different fields like technology, hospitals & everywhere. You will get quality medical cables from Peterstechnology.com at an affordable price.
Frequency is defined as the number of cycles per minute.
Ex: for a sine wave from " 0 to pi " is a cycle, and this repeats periodically within a interval of time.
if frequency of a signal is 50Hz, then you can say that this signal repeats 50 time's a minute..
