Every transmission line requires termination, either in the form of the ultimate load, such as an antenna, or in the form of some kind of resistor. 10BaseT is no different.

However, that termination is usually built in to the device in which the cable is plugged. This is different from older systems, such as ArcNet, where the coax cable requires termination on each of the far ends. This is because the 10BaseT system is a star system rather than a partial ring system, so the termination is not a function of the chosen topology.

The reason termination is required in a transmission line is that every step change in characteristic impedance encountered by the wave front as it propagates through the line results in some kind of reflection back towards the source. These reflections result in distortion, loss of power, even damage to the transmitter or circuit.

To reinforce this understanding, consider the 75 Ohm coax cable typically used in a television distribution system. In the simplest case, you connect a cable from the service entrance to the TV set, and you are properly terminated. If, however, you use a splitter, such as for a TV set and a VCR, you now have three transmission lines, one to the splitter and two from the splitter. Is the RF output of the VCR connected to something? It should be, either to a TV set or to a terminator, otherwise there will be problems due to ringing, interference, ghosting, etc.

The answer is either. Network switches are pretty simple and so one is as good as another. The same is true if you mean to ask about routers. Hubs are not used any longer nor were they ever used in the Ethernet arena. Hubs were used for an old, no longer used technology called Arcnet. Ethernet used something else called concentrators but even those are no longer used today because of the amount of transmission collisions that they endured because of the design of the technology, especially on busier networks.

The explanation of the difference of the various technologies (routers, hubs, concentrators, and switches) is beyond the scope of what the question seeks, so I will advise you to post another question if you wish to learn the differences. For this question, though, suffice it to say that any competent brand will serve your needs well. The brands that I recommend are Linksys, D-Link, Netgear, Edimax, TP-Link, and Trendnet and this list is not in any particular order. All are just as good as the rest. Two brands to avoid, however, are Belkin and Linkskey. Notice the spelling difference between Linksys (a good brand) and Linkskey (a bad brand) and do not get them confused. They are as different as night and day. Linkskey (in my not so humble opinion) chose their name so as to try to capitalize on the average Joe's confusion regarding how to pronounce the name "Linksys" since many people did already pronounce it as "Linkskey." Their network products, in my professional experience, have been about as useful as a pad of Post-It Notes at a basketball game. In other words, practically useless! As for Belkin, their products seem to work well for awhile but from what I have seen, their longevity is about a year or so, just long enough to outlive their warranties. The brands I recommend are like the old Energizer bunnies: they keep going and going and...

If you have any other questions or wish further advice in regard to the offerings of the different brands, feel free to drop me a line. I'm glad to help.

To begin we have to define "networking" Websters dictionary defines "networking" as: : the establishment or use of a computer network.

Basically, communication of data between two or more computers. In the early days of computers, local area networking was handled primarily through the use of serial communications. Token Ring, AppleTalk and Arcnet were some of the earlier protocols used for local area networking. With the introduction of "ethernet" cabling around 1975, and the development of TCP/IP, speeds increased and we now have local area networks capable of speeds exceeding 10Gbs.

Historically, wide area networking (Networks between computers not physically close to each other) was usually handled by modems over telephone lines. Although, in industrial applications point to point "high speed" circuits were made available at great expense. Some of these protocols include T-1 and T-3 connections and ISDN systems. With the invention of the internet and it's wide acceptance, and the introduction of "high speed" internet connections such as DSL, Cable and Fiber in the Home, networking began to use TCP/IP protocols for wide area networks more and more, with the majority of interconnected computers now using TCP/IP for both LAN and WAN applications.

Over the coming years we'll see networking evolve even further with the adoption of IPv6. Currently the majority of networks are using IPv4 which has a maximum of just over 4.2 billion unique addresses. Whereas IPv6 is capable of approximatley 340 Trillion unique addresses. Other innovations that we'll see in the world of networking will include wide area fiber optic connections, new transmission protocols that will raise current internet connection speeds from an average of around 3Mbs in 2010 to a speeds in excess of 100mb in the coming decades.

Networking is exciting. My first LAN was a Token ring network running on coaxial cable with a 4 Mbs speed and latency that was practically measured in seconds. Now I'm in charge of an ethernet network that is comprise primarily of Gigabit connections with a few 100Mbs connections and a couple of 10Gbs connections. My first WAN was a 300 baud modem that I used to dial up a connection with my buddy across town, now I have a 20Mbs internet connection running on fiber optic lines. We'll see how networking evolves in the future, but it looks to be extremely promising.

You would have to be logged in as the administrator.

ANSWER

It depends on your operating system. A kernel is basicaly a line of code, different kernels control different operations for different systems within the computers program.

The closest thing to obtainging a true "kernel mode" is to run an open source Operating system like linux.

With something like windows you can obtain through administrative tools access to operating system programms, you can't truly rewrite (easily) the programs within your system.

A process transitions from user mode to kernel mode usually with some form of software interrupt. On x86 CPU's, the "INT 0x80" instruction is commonly used for running system calls. The kernel traps this software interrupt, processes the request, and returns to user mode by returning from the interrupt. This describes how real operating systems like Linux and FreeBSD work. Windows may work similarly to this, but it's not a real operating system anyway.

A modern symmetrically multi-processing operating system typically, today, consists of millions of lines of code. Most of these, eg Windows, Linux, FreeBSD, NetBSD, OpenBSD among many others, are written in the 'C/C++' programming language.

The above mentions INT 0x80 as being used on x86 CPUs, the author above is absolutely correct, though the answer could be further refined to say that INT 0x80 is specific to the Linux operating system kernel as being the maskable software interrupt used to invoke a system call (whether that be on ring -1, ring 0 or another ring if other rings are available on a given architecture - eg, VMware probably supports ring -1 on architectures supporting ring -1 so that guest operating systems may have free access to ring 0). That may well be the longest sentence I've ever written. :)

As INT 0x80 is a Linux maskable interrupt, it would also be used on other architectures as well such as Sun Microsystems SPARC or Digital Equipment Corporation VAX machines.

System calls (or SysCall/SysEnter) are used for many other purposes, particularly to access various hardware devices such as locally attached disk drives, USB devices, SCSI devices, Network (eg Ethernet [including Arcnet or Token Ring, assuming such things still exist]) cards or other bus attached devices etc.

I must agree with the above author's last sentence as well, though a Rockwell International engineer I once knew classified Windows as a 'virus' as opposed to a 'real' operating system like Linux (probably because Windows tends to proliferate as well as wreak havoc upon it's users).

Actually, you do not use a hub in any case. Hubs were used in an old technology of networking called Arcnet but that hasn't been used in about 20 years. What you have in the modern network is properly referred to as a switch and it has a very different purpose than a hub but that is not germane to your question, so I will digress no longer.

No, you do not need to use a switch to get two computers to talk to each other. What you can do, as Rtrahan stated, is use what is often called a crossover (or more properly cross-connect) cable. What it does is reverse the two pairs of wires so that what is the receive pair on one end is the transmit pair on the other end. In an Ethernet cable, only four wires are used: pins 1, 2, 3, and 6. with 1 and 2 being one pair and 3 and 6 being the other. The order is counted from left to right as the flat side of the plug (the side without the retaining clip) is facing you. To make a cross-connect cable, you switch pins 1 and 3 and then 2 and 6 on one end of the cable. Once you have done that, though, there is still more to do.

Now that you have them connected so that there is no longer any sort of other device between the two, you need to tell them how to address each other. The easiest way to do this, since there is no DHCP server involved due to the two machines being directly linked to one another, is to give them both a static IP address. Presuming that you are using Windows 7, you would accomplish this by going into the Network and Sharing Center control panel applet, clicking on the blue phrase "Local area connection," and then clicking on the Properties button toward the bottom of the window that appears. Once you have done that, another window appears and you should see a selection for "Internet Protocol Version 4 (TCP/IPv4)." Double-click on that and another window will appear. In here, you will be able to set the IP address, subnet mask, and default gateway. For your purposes and since you are not connected to anything else, I would recommend just setting the IP address and subnet mask. You can make the addresses whatever you want provided that the two machines are within the same IP subnet. So, for example, if you want to set 10.0.0.157 for one IP address and the other as 10.0.3.201, then you would need to set your subnet mask to 255.255.252.0 If it was set to 255.255.255.0, then the two machines would be in separate subnets and not be able to talk to each other without a router.

I hope this helps. If you need any further assistance or if something is just about as clear as mud, feel free to drop me a line and I'll see what I can do to help you.

oken-Ring was initially successful for IBM - as most IBM-endorsed technologies are. But beyond IBM, it never garnered much support among top-tier vendors, which gravitated toward Ethernet, the preferred LAN technology of research institutions and manufacturing companies.

Token-Ring began its downward spiral soon after the emergence of 10Base-T Ethernet, an inexpensive, 10Mbps transmission technology than ran across telephone grade unshielded twisted-pair copper media. Matters were not helped when Soderblom began demanding royalties from the few Token-Ring vendors and chip makers, driving prices higher.

Stations on a token ring LAN are logically organized in a ring topology with data being transmitted sequentially from one ring station to the next with a control token circulating around the ring controlling access. This token passing mechanism is shared by ARCNET, token bus, and FDDI, and has theoretical advantages over the stochastic CSMA/CD of Ethernet. Physically, a token ring network is wired as a star, with 'hubs' and arms out to each station and the loop going out-and-back through each. Cabling is generally IBM "Type-1" shielded twisted pair, with unique hermaphroditic connectors, commonly referred to as IBM data connectors. The connectors have the disadvantage of being quite bulky, requiring at least 3 x 3 cm panel space, and being relatively fragile.

Initially (in 1985) token ring ran at 4 M bit/s, but in 1989 IBM introduced the first 16 M bit/s token ring products and the 802.5 standard was extended to support this. In 1981, Apollo Computer introduced their proprietary 12 M bit/s Apollo token ring (ATR) and Proteonintroduced their 10 M bit/s ProNet-10 token ring network in 1984. However, IBM token ring was not compatible with ATR or ProNet-10. Each station passes or repeats the special token frame around the ring to its nearest downstream neighbor. This token-passing process is used to arbitrate access to the shared ring media. Stations that have data frames to transmit must first acquire the token before they can transmit them. Token ring LANs normally use differential Manchester encoding of bits on the LAN media.

IBM popularized the use of token ring LANs in the mid 1980s when it released its IBM token ring architecture based on active MAUs (Media Access Unit, not to be confused with Medium Attachment Unit) and the IBM Structured Cabling System. The Institute of Electrical and Electronics Engineers (IEEE) later standardized a token ring LAN system as IEEE 802.5.Token ring LAN speeds of 4 Mbit/s and 16 Mbit/s were standardized by the IEEE 802.5 working group. An increase to 100 Mbit/s was standardized and marketed during the wane of token ring's existence while a 1000 Mbit/s speed was actually approved in 2001, but no products were ever brought to market.

LAN is a Local Area Network A LAN is the short abbreviation for Local Area Network. In a LAN you usually have many computers connected together using ehternet, Wifi, etc. The computers in Lan have the ability to share resources such as printers, scanners, hard drive space, and an internet connection. The inter net is also a network but a much larger scale LAN usually refers to a small network like the computers in one house, company, school, etc. Answer A local area network (LAN) is a computer network covering a small physical area, like a home, office, or small group of buildings, such as a school, or an airport. The defining characteristics of LANs, in contrast to wide-area networks (WANs), include their usually higher data-transfer rates, smaller geographic place, and lack of a need for leased telecommunication lines. Ethernet over unshielded twisted pair cabling, and Wi-Fi are the two most common technologies currently, but ARCNET, Token Ring and many others have been used in the past. The ITU-T G.hn standard provides a way to create a high-speed (up to 1 Gigabit/s) Local area network using existing home wiring (power lines, phone lines and coaxial cables). Answer: A local area network (LAN) consists of two or more computers connected together in a building or home using software and hardware. A LAN is contrasted to a wide area network (WAN) such as the Internet, which covers a large geographic area. In a LAN, there is a main computer or server, and remote computers called clients. By creating a LAN in the home or office, computers on the LAN can share files, resources, and if desired, an Internet connection.

A Local Area Network (LAN) is a network that is confined to a relatively small area. It is generally limited to a geographic area such as a writing lab, school, or building.

Computers connected to a network are broadly categorized as servers or workstations. Servers are generally not used by humans directly, but rather run continuously to provide "services" to the other computers (and their human users) on the network. Services provided can include printing and faxing, software hosting, file storage and sharing, messaging, data storage and retrieval, complete access control (security) for the network's resources, and many others.

Workstations are called such because they typically do have a human user which interacts with the network through them. Workstations were traditionally considered a desktop, consisting of a computer, keyboard, display, and mouse, or a laptop, with with integrated keyboard, display, and touchpad. With the advent of the tablet computer, and the touch screen devices such as iPad and iPhone, our definition of workstation is quickly evolving to include those devices, because of their ability to interact with the network and utilize network services.

Servers tend to be more powerful than workstations, although configurations are guided by needs. For example, a group of servers might be located in a secure area, away from humans, and only accessed through the network. In such cases, it would be common for the servers to operate without a dedicated display or keyboard. However, the size and speed of the server's processor(s), hard drive, and main memory might add dramatically to the cost of the system. On the other hand, a workstation might not need as much storage or working memory, but might require an expensive display to accommodate the needs of its user. Every computer on a network should be appropriately configured for its use.

On a single LAN, computers and servers may be connected by cables or wirelessly. Wireless access to a wired network is made possible by wireless access points (WAPs). These WAP devices provide a bridge between computers and networks. A typical WAP might have the theoretical capacity to connect hundreds or even thousands of wireless users to a network, although practical capacity might be far less.

Nearly always servers will be connected by cables to the network, because the cable connections remain the fastest. Workstations which are stationary (desktops) are also usually connected by a cable to the network, although the cost of wireless adapters has dropped to the point that, when installing workstations in an existing facility with inadequate wiring, it can be easier and less expensive to use wireless for a desktop.

Local area network. Simpy put a LAN covers a small area such as one site or in one building, eg a school or a college.

where a WAN, as an example is the "Internet" or a simple example; all of one banks cash machines across the country.

A LAN can be part of a WAN i.e. a school network is connected to the internet (WAN).

A computer network limited to a relatively small local area (e.g. a single residence or office) as opposed to a large wide area (e.g. internet). A LAN may or may not be connected to an external WAN, or may or may not be connected to other LANs without being connected to a WAN.

Comparison chart

Improve this chart

LAN

WAN

Data transmission Error:

Experiences fewer data transmission errors

Experiences more data transmission errors as compared to LAN

Data transfer rates:

LANs have a high data transfer rate

WANs have a lower data transfer rate as compared to LANs

Technology:

Tend to use certain connectivity technologies, primarily Ethernet and Token Ring

WANs tend to use technology like MPLS, ATM, Frame Relay and X.25 for connectivity over the longer distances

Connection:

one LAN can be connected to other LANs over any distance via telephone lines and radio waves

Computers connected to a wide-area network are often connected through public networks, such as the telephone system. They can also be connected through leased lines or satellites

speed:

high speed(1000mbps)

less speed(150mbps)

Maintenance costs:

Because it covers a relatively small geographical area, LAN is easier to maintain at relatively low costs.

Maintaining WAN is difficult because of its wider geographical coverage and higher maintenance costs.

Fault Tolerance:

LANs tend to have less problems associated with them, as there are a smaller amount of systems to deal with.

WANs tend to be less fault tolerant. as it consists of a large amount of systems there is a lower amount of fault tolerance.

Example:

Network in an organization can be a LAN

Internet is the best example of a WAN

Geographical spread:

Have a small geographical range and do not need any leased telecommunication lines

Have a large geographical range generally spreading across boundaries and need leased telecommunication lines

Set-up costs:

If there is a need to set-up a couple of extra devices on the network, it is not very expensive to do that

In this case since networks in remote areas have to be connected hence the set-up costs are higher

Ownership:

Typically owned, controlled, and managed by a single person or organization

WANs (like the Internet) are not owned by any one organization but rather exist under collective or distributed ownership and management over long distances

Definition:

LAN (Local Area Network) is a computer network covering a small geographic area, like a home, office, schools, or group of buildings.

WAN (Wide Area Network) is a computer network that covers a broad area (e.g., any network whose communications links cross metropolitan, regional, or national boundaries over a long distance

Components:

layer 2 devices like switches, bridges. layer1 devices like hubs , repeaters

Layers 3 devices Routers, Multi-layer Switches and Technology specific devices like ATM or Frame-relay Switches etc.

A local area network (LAN) exists in a house or a university campus, while a wide area network (WAN) exists over many office buildings separated by a vast distance. The office buildings in a WAN may be in different countries or even continents. For example, the headquarters building may be in the USA, the regional office building may be in the UK, and the branch office building may be in India. The workers in the three buildings use WAN to collaborate with each other. The Internet can also be considered as a WAN. Let's take a look at the LAN vs. WAN comparison check.

Difference between LAN and WAN

The other difference between LAN and WAN, is the speed of thenetwork. The maximum speed of a LAN can be 1000 megabits per second, while the speed of a WAN can go up to 150 megabits per second. This means the speed of a WAN, is one-tenth of the speed of a LAN. A WAN is usually slower because it has lower bandwidth.

Computers in a LAN can share a printer, if they are all in the same LAN. On the other hand, a WAN cannot share a printer, so a computer in one country cannot use a printer in another country. A LAN does not need a dedicated computer to direct traffic to and from the Internet, unlike a WAN that needs a special-purpose computer, whose only purpose is to send and receive data from the Internet.

Another LAN vs. WAN comparison is the cost of the network. A WAN is more expensive than a LAN. It is easier to expand a LAN than a WAN. The equipment needed for a LAN is a network interface card (NIC), a switch and a hub. On the other hand, the equipment needed to connect a WAN to the Internet is a modem and a router. The modem may be a cable modem or a DSL modem that is connected to a wall jack, while the router should be configured so that it can handle the packets traveling between the WAN and the Internet.

In LAN vs. WAN, there is a difference in the networking standard used. A LAN uses the Ethernet standard, while a WAN uses the T1 standard. Before Ethernet, the protocols used for LAN were Attached Resource Computer Network (ARCNET) and Token Ring. The protocols used for WAN are Frame Relay and Asynchronous Transfer Mode (ATM). Another protocol for WAN is Packet over SONET/SDH (PoS), where SONET stands for Synchronous Optical Networking and SDH stands for Synchronous Digital Hierarchy. The first WAN protocol was X.25, while an advanced WAN protocol is Multiprotocol Label Switching (MPLS). The hardware in a LAN is connected with 10Base-T cable connectors, while a WAN is connected via leased lines or satellites.

Here is an explanation of LANs and WANs. A LAN is easy to set up, as you need to slip the NIC into the PCI slot (for desktop computers) or PCMCIA slot (for laptop computers). You also need to install the driver for the NIC. The NIC can be connected to the network using the RJ45 port.

On the other hand, a WAN is very difficult to set up. There is often an appliance to optimize the WAN. There is also a device to cache WAN data, so workers in the branch office can quickly access documents. The router also has Quality of Service (QoS) built in, so that it gives priority to certain kinds of traffic.

There are various topologies available in LAN and WAN networking. The most common topologies in LAN and WAN networks are ring and star. The ring topology is a network in which every node (every computer) is connected to exactly two other nodes. The star topology is a network in which all the nodes (called leaf nodes or peripheral nodes) are connected to a central node.