Microsoft Windows XP Networking Inside Out
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Part 1: Windows XP Networking
9Click Finish. The new connection appears in the Network Connections window as Incoming Connections.
Once you have the host set up, your next task is to set up the guest computer. For Windows XP computers, simply use the New Connection Wizard again and
select the Guest option instead of Host on the wizard’s Host Or Guest page. If you are using another version of Windows as the guest, refer to that operating system’s help files for setup instructions. In Windows XP, the connection on the guest computer appears under the Direct heading in Network Connections, as you can see in Figure 3-4. Simply double-click the icon to make the connection, and then enter a valid user name and password.
Keep in mind that you can create multiple DCC connections to connect different pairs of computers as needed, although only one connection can be active at a time. Simply create the DCC connections, enter the computer name that you want to connect to, and select the appropriate port.
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Figure 3-4. The DCC connection appears on the guest computer in Network Connections under the Direct heading.
Managing Direct Connection Security
If you are using DCC for a device such as a palmtop computer, you can bypass the security option for the user name and password by following these easy steps:
1On the host computer, open Network Connections.
2Right-click the Incoming Connection item and choose Properties.
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3On the Users tab, select the check box labeled Always Allow Directly Connected Devices Such As Palmtop Computers To Connect Without Providing A Password. Click OK.
On the other hand, to increase security, you can also require that secure passwords and data encryption be used on the DCC network connection. Typically, you don’t need these highly secure methods for such an ad hoc connectivity solution (if others can access your computer directly, chances are they’re already bypassing much of your security), but the options are easy to configure and seamless to use. To require data encryption for the DCC connection, follow these steps:
1 On the host computer, right-click the Incoming Connections item and choose Properties. On the Users tab, select Require All Users To Secure Their Passwords And Data. Note that this setting applies to other computers that connect to the host, not devices such as palmtop computers. Click OK.
2 On the guest computer, open Network Connections, right-click the DCC item, and choose Properties. On the Security tab, shown in Figure 3-5, select Typical;
then select Require Secured Password from the Validate My Identity As Follows |
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list. Finally, select Require Data Encryption (Disconnect If None) and click OK. |
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Figure 3-5. Select these options to require encryption and a secure password for your DCC connection.
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Ethernet Networks
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Ethernet is a networking standard that has been around since the mid 1970s when Xerox introduced the first Ethernet product. Ethernet is a network standard that is defined by the Institute of Electrical and Electronics Engineers (IEEE) 802.3 specification. It has been and continues to be overwhelmingly popular. In fact, most home and small office networks are Ethernet networks, and the vast majority of larger networks use Ethernet as well. For this reason, most NICs and networking equipment, except for more specialized networks like HomePNA and wireless, use the Ethernet standard. Even wireless networks use a form of Ethernet. When you set out to connect a group of computers using NICs, a hub, and RJ-45 cables, you are creating an Ethernet network.
So, what is Ethernet exactly? Ethernet is a set of specifications that define how the hardware used to create a network communicates and functions. For this reason, you can use network adapter cards created by different manufacturers and even a network hub created by yet another manufacturer, and all of the components will work together. Manufacturers adhere to the Ethernet 802.3 specification so that you can mix and match hardware without problems. If you want to read about the 802.3 specification, you can find it using a quick search on the Internet, but the rest of this section highlights the pertinent information. In fact, you’ll find a few terms and concepts that you might also see listed on manufacturers’ Ethernet documentation and packaging.
How Ethernet Sends Data
The 802.3 specification defines how data must be sent over an Ethernet network. Ethernet breaks data into small pieces called frames. Each frame contains between 46 and 1500 bytes of data. When you send data over an Ethernet network, the data is broken down into frames, sent over the wire, and then reassembled by the receiving computer.
Each frame contains header information noting the beginning of the frame, where it is coming from, and where the frame is going. Additionally, each frame has a component called a cyclical redundancy check (CRC). The CRC allows the receiving computer to check the frame to make sure that the data in the frame has arrived intact. If it has not, the receiving computer can use the header information to request that the sending computer resend the data. This frame-sending format has been used for years and is highly reliable.
Ethernet is considered a bus topology, which refers to the shared physical layout of the network. More commonly, Ethernet is called a star-bus topology because all computers radiate from a central hub that resembles a star pattern, as shown in the following illustration.
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Ethernet Star-Bus Topology
Hub
LAN clients
Access Method
Chapter 3
Ethernet networks use the Carrier Sense Multiple Access with Collision Detection (CSMA/CD) access method to send data over the network and manage transmission problems. (In fact, if you have been studying residential gateways and related products, you might have noticed that the CSMA/CD method appears on the products’ specification sheets.) CSMA/CD does not need to be configured—it just tells you that the device fully supports Ethernet’s mechanism for sending data.
CSMA/CD uses a method where computers listen to the network cable to see if any other computers are transmitting frames. If not, the computer sends the data. If there is traffic, the computer waits until the line is clear. In the event that two computers transmit data on the wire at the same time, a collision will occur. In this case, the data is destroyed. However, the Collision Detection feature of CSMA/CD enables the computers to detect the collision so that data can be resent.
Ethernet Speed
Ethernet devices can support three speed standards:
●10Base-T. 10Base-T is an Ethernet standard that simply means 10 Mbps baseband over twisted-pair wiring. Baseband means a single message is
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carried at a time (broadband carries multiple messages simultaneously). Remember that Ethernet networks typically use unshielded twisted-pair (UTP) wiring with RJ-45 connectors, which are wider versions of the standard RJ-11 telephone connectors found at the back of your phone and plugged into phone jacks. 10Base-T is an older Ethernet standard and is capable of a maximum speed of 10 Mbps.
●100Base-T (Fast Ethernet). 100Base-T networks use the same Ethernet standard, but are capable of up to 100 Mbps. Most hubs and network adapters sold today are considered 10/100 Ethernet. This means that they can automatically adjust for 10 Mbps communication or 100 Mbps communication, depending on what is supported by the rest of the network. Fast Ethernet requires at least Category 5 quality UTP wiring.
●1000Base-T (Gigabit Ethernet). Gigabit Ethernet is a new speed standard of 1000 Mbps, or 1 gigabit per second (Gbps). You’ll find a number of Gigabit hubs and NICs at your local computer store. This standard is great for high-speed video transfer and related multimedia applications. To take full advantage of Gigabit Ethernet, all computers should be outfitted with a 1 Gbps NIC, and you’ll also need a 1 Gbps hub. The 1000Base-T standard also requires at least Category 5 quality UTP wiring.
note Other standards for Ethernet cabling exist, such as 10Base-2 (often referred to as thinnet) or 10Base-5 (also known as thicknet). These standards use coaxial cabling in a true bus configuration. All systems must be connected in series (like links in a chain) to maintain the network’s integrity, and a break anywhere in the cabling (or even an improperly disconnected workstation) can bring down an entire segment. These older
standards are becoming less and less common, and are undesirable for new installations.
Is Ethernet Right for You?
Now that you know a little about Ethernet, you might wonder whether Ethernet is the kind of network you need. Table 3-1 explores the fundamental issues to consider before using Ethernet.
Table 3-1. Ethernet Networking Features
Networking Issue |
Ethernet Feature or Failure |
Expense |
Ethernet NICs, hubs, wiring, and gateways are all reasonably |
and availability |
priced. You can also find Ethernet kits. All major networking |
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manufacturers produce Ethernet products, and you can find |
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Ethernet NICs for as little as $30. Hubs and switches can |
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cost from $40 to $400 for models combining firewalls and |
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switches for large workgroups. |
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Table 3-1. (continued) |
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Networking Issue |
Ethernet Feature or Failure |
Setup |
Easy. Windows XP can automatically install NICs, and |
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hub configuration is easy. |
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Speed |
Up to 1 Gbps with 10/100 being the standard at this time. |
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Ethernet is the fastest type of network for the home or |
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small office. |
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Cabling |
Cabling can be difficult to run in homes or existing busi- |
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nesses and can be an eyesore if wall outlets are not available |
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or installed. |
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Reliability |
Excellent. |
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If you decide that an Ethernet network is right for you, keep the following issues in mind:
●You need NICs, a hub with enough ports for your network (or multiple hubs), and Category 5 cabling.
●Each cable length is limited to a maximum of 328 feet, which normally isn’t a problem in a home or small office network.
●Residential gateways are available that work with Ethernet if you want to use a gateway instead of ICS.
Chapter 3
For more information about ICS, see “Using Internet Connection Sharing,” page 301.
HomePNA Networks
HomePNA is a standard that was introduced a few years ago when home and small office networking started to become popular. A HomePNA network uses internal PCI NICs or external USB NICs like Ethernet, but these NICs use RJ-11 connectors, the type used by telephone connections. Not only are the plugs the same, but you plug the NIC into a nearby phone jack (one used for a telephone circuit), and the NIC uses the home or office’s internal phone wiring for network data transfer. Other users who need access to the network do the same. In homes where most rooms have a phone jack, HomePNA gives you access to a network from virtually any room in the house or office—without a hub.
Whereas Ethernet uses a star-bus topology, HomePNA networks use a daisy chain topology. Computers simply plug into the existing phone line system in the home and send data over that system to the desired computer, as shown in the following illustration. The advantages are that no central hub is required, and the network lines are already installed inside the walls. All you have to do is connect. The network connections
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do not interfere with voice communications on the phone lines, so you can talk on the phone and use the network at the same time.
Hubless LAN Running over
Existing Telephone Wiring
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Telephone |
LAN clients |
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outlets |
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LAN client
If all of this sounds too good to be true, rest assured that HomePNA is not the perfect solution. There are two primary problems with HomePNA that you should consider before adopting it. First, HomePNA networks are limited to about 10 Mbps, which is much slower than Fast Ethernet or Gigabit Ethernet. However, how much speed do you really need? This is an important question to consider, and some points to keep in mind are:
●If you use the network to share printers, files, and other peripherals, 10 Mbps is all you need.
●If you share a broadband Internet connection, 10 Mbps is fast enough because you do not receive data from the Internet any faster than 10 Mbps. Although there might be a slight slowdown using the HomePNA network, the difference is usually not noticeable.
●If you play multiuser games, 10 Mbps is fast enough as long as the games are not too graphics-intensive. If they are, you’ll notice some delays.
●If you are running video applications and other multimedia, you’ll experience delays with 10 Mbps.
●If you run some of the computers on your network remotely using Remote Desktop at high resolution and color depth, you’ll notice hesitations in some operations such as screen redraws and moving objects about on the screen.
So, if basic networking and Internet sharing is all you need, the HomePNA network will work well and solve your cabling problems. If speed is an issue for you, Fast Ethernet or Gigabit Ethernet is the better choice.
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The second problem with HomePNA concerns ICS. If you are using a DSL or cable modem, you’ll need a NIC for that connection as well as the HomePNA NIC. You can set up ICS with the ICS host computer connected to the Internet, and all other computers will access data from the ICS host. However, if you do not want to use ICS, you’ll need to purchase a network device called a bridge. A bridge connects two dissimilar networks, such as an Internet connection with the HomePNA LAN. These bridge solutions are readily available, but will certainly add to your hardware cost.
tip If you need to connect dissimilar networks, there is an easy software-based solution included in Windows XP called Network Bridge. You can learn more about network bridges in “Bridging Network Connections,” page 75.
So, is HomePNA what you need for your home or office? Consider the information in Table 3-2 as you make your decision.
Table 3-2. HomePNA Networking Features
Networking Issue |
HomePNA Feature or Failure |
Expense |
HomePNA networks require HomePNA NICs and standard |
and availability |
phone cabling. They are often sold as kits for around $50, |
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so they are very affordable. You’ll find plenty of manufac- |
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turers of HomePNA products at your local computer store. |
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Setup |
Easy. Windows XP can automatically install the NICs, and |
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the manufacturer usually provides a setup CD. |
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Speed |
Networks are limited to 10 Mbps, which is considerably |
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slower than Fast Ethernet or Gigabit Ethernet. |
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Internet |
Connecting the LAN to a shared Internet DSL or cable |
connections |
connection can require extra hardware. |
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Reliability |
Excellent. |
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If you are still unsure about whether to use Ethernet or HomePNA, consider all the points in this section, and then revisit this simple idea—if running Ethernet cable between computers and a hub is not a problem, use Ethernet. This way, you won’t have any speed problems, and you’ll have more residential gateway and router options than are provided with HomePNA. If connections between computers are difficult to achieve with cabling, HomePNA might be your best bet. You can learn more about HomePNA at www.homepna.org. However, before choosing HomePNA, you might also want to consider a wireless network, which you can learn more about in Chapter 19, “Wireless Networking.”
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Powerline Networks
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Powerline networking is a lot like HomePNA, but instead of using your existing telephone lines, you use your electrical lines. That’s right, Powerline networking uses a NIC that plugs into a standard AC outlet. Other computers in your home plug into other outlets, and communication between computers occurs over the electrical lines without disrupting any other electrical services.
Powerline networking also provides speeds of 8–14 Mbps transfer, so the system’s speed is comparable to that of HomePNA. So why use Powerline? The main reason for using Powerline networking is that AC receptacles are more readily available in homes and offices than telephone jacks, which gives you more networking flexibility.
Is Powerline a better, more flexible choice than HomePNA? Not really. You face the same speed and Internet connection challenges as HomePNA, and Powerline networking can be problematic, although sales brochures might tell you otherwise.
Powerline technologies have had a lot of problems in the past due to noise and distortion on traditional power lines within the home. For example, your home network might work fine until someone turns on a hair dryer or a toaster. Then, the static and interference could bring the network to a standstill. However, recent developments in the ways that Powerline NICs use frequencies over cabling enable the Powerline network to adjust frequencies as needed, so that network disruptions are not as problematic. Also, some providers use an encryption method for all network communications in the event that data gets transmitted from the local home or office onto the main power line.
Powerline networking is a practical and viable alternative, and one that continues to mature. In fact, you might see more and more Powerline offerings including broadband Internet over power lines in the near future, so this is certainly a technology to keep your eye on. For the home and small office network, this technology does work well, although you can expect some hiccups from time to time. If you think that Powerline networking might be right for you, be sure to purchase the required equipment from a recognized manufacturer, and review Table 3-3 for a summary of features. To learn more about Powerline networking, go to www.homeplug.com.
Table 3-3. Powerline Networking Features
Networking Issue |
Powerline Feature or Failure |
Expense and availability |
Most kits cost between $50 and $100. You do not |
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need a hub for Powerline networking. |
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Setup |
Easy. Windows XP can automatically install the NICs, |
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and the manufacturer usually provides a setup CD. |
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Speed |
Network speeds run up to 8–14 Mbps, which is consid- |
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erably slower than Fast Ethernet or Gigabit Ethernet. |
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You might see more dips in speed and service than you |
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typically do with HomePNA. |
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Table 3-3. (continued) |
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Networking Issue |
Powerline Feature or Failure |
Internet connections |
Connecting your LAN to a DSL or cable Internet con- |
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nection can require additional hardware. Also, network |
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service disruption due to Powerline conditions can |
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cause problems as well. |
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Reliability |
Good. |
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Wireless Networks
Windows XP fully supports the wireless networking standard, which makes Windows XP the best Microsoft operating system to use if you want a wireless network. Typical wireless networks use radio signals between wireless NICs and access points (similar to hubs), but they are more expensive and not as fast as wired Ethernet. Chapter 19, “Wireless Networking,” is devoted entirely to the subject.
Other Types of LANs
There are a few other common types of networks that are used for LANs. These types of networks are more expensive and complicated than the types of networks outlined in this chapter, so they are not used as home or small office networks. You will, however, see them in some corporate LANs, and Windows XP Professional will function on these types of networks as well.
●Token Ring. Token Ring networks are sometimes used in large LANs as an alternative to Ethernet. Token Ring networks use a token passing technology in which any computer sending data must have an electronic ticket, or token, before transmitting data over the wire. Due to the token passing scheme, Token Ring networks do not need Ethernet’s CSMA/CD access method because collisions cannot occur with the token structure. IBM developed the Token Ring technology, which was later standardized in the IEEE 802.5 standard. In a Token Ring network, all computers are wired to a physical ring or loop along which the token is passed. This type of network is more complex than Ethernet, but it is a somewhat common network topology.
●Fiber Distributed Data Interface (FDDI). FDDI also uses a token passing technology to move data. FDDI is capable of 100 Mbps transfer speeds. FDDI is a lot like Token Ring, but it uses fiber-optic cable with a two-ring design (the secondary ring can be used for data and as a backup should the primary ring fail). FDDI is used in many environments, but it is not as popular as Ethernet or conventional Token Ring networks. Due to the expense of the fiber-optic connections, it is primarily used in providing backbones
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