Peer-to-peer Network

In a peer-to-peer network, computers are linked together for resource sharing. If there are only two computers to link together, networking can be done with a Category 5 crossover cable that plugs into the RJ45 jack of the network interface card (NIC) on each computer. If the computers do not have NICs, they can be connected with either a serial or parallel cable.

Once connected, the two computers function as if they were on a local area network (LAN), and each computer can access the resources of the other. If three or more computers must be connected, a wiring hub is required. The peer network can be extended to portable devices, including desktop and notebook computers and personal digital assistants (PDAs), through the use of wireless access points.

The access point connects to the LAN through a hub or switch via Category 5 cabling, just like any other device on the wired network. The access point establishes the wireless link to one or more client devices, which are equipped with a wireless card. The wireless devices operate in either the 2.4-GHz band for 11 Mbps or the 5-GHz band for 54 Mbps.

Newer access points have slots for wireless cards of both frequency bands, allowing users to protect investments in 2.4-GHz equipment while migrating to the higher speeds offered by 5-GHz equipment. Regardless of exactly how the computers are interconnected, wired or wireless, each is an equal or “peer” and can share the files and peripherals of the others.

For a small business doing routine word processing, spreadsheets, and accounting, this type of network is the low-cost solution to sharing resources like files, applications, and peripherals. Multiple computers can even share an external cable or Digital Subscriber Line (DSL) modem, allowing them to access the Internet at the same time.

Networking with Windows

Windows 95/98 and Windows NT/2000 are often used for peerto- peer networking. In addition to peer-to-peer network access, both provide network administration features and memory management facilities, support the same networking protocols— including the Transmission Control Protocol/Internet Protocol (TCP/IP) for accessing intranets, virtual private networks (VPNs), and the public Internet—and provide such options as dial-up networking and fax routing.

One difference between the two operating systems is that in Windows 95/98 the networking configuration must be established manually, whereas in Windows NT/2000 the networking configuration is part of the initial program installation, on the assumption that NT/2000 will be used in a network.

Although Windows 95/98 is good for peer-to-peer networking, Windows NT/2000 is more suited for larger client-server networks. Windows supports Ethernet, Token Ring, Asynchronous Transfer Mode (ATM), and Fiber Distributed Data Interface (FDDI) data-frame types. Ethernet is typically the least expensive network to implement.

The NICs can cost as little as $20 each, and a five-port hub can cost as little as $40. Category 5 cabling usually costs less than 50 cents per foot in 100-foot lengths with the RJ45 connectors already attached at each end. Snap-together wall plate kits cost about $6 each.

If wireless connections are part of the peer network, the wireless NICs cost between $170 and $300, depending on whether the 2.4- or 5-GHz band is used. Access points can cost as little as $199 for 2.4-GHz units and $299 for 5-GHz units. Enterprise class versions cost quite a bit more.

Configuration Details

When setting up a peer-to-peer network with Windows 95/98, each computer must be configured individually. After installing an NIC and booting the computer, Windows will recognize the new hardware and automatically install the appropriate network-card drivers. If the drivers are not already available on the system, Windows will prompt the user to insert the manufacturer’s disk containing the drivers, and they will be installed automatically.

Next, the user must select the client type. If a Microsoft peer-to-peer network is being created, the user must add “Client for Microsoft Networks” as the primary network logon. Since the main advantage of networking computers is resource sharing, it is important to enable the sharing of both printers and files. The user does this by clicking on the “File and Print Sharing” button and choosing one or both of these capabilities.

Through file and printer sharing, each workstation becomes a potential server. Identification and security are the next steps in the configuration process. From the “Identification” tab of the dialog box, the user must select a unique name for the computer and the workgroup to which it belongs, as well as a brief description of the computer. When others use Network Neighborhood to browse the network, they will see the menu trees of all active computers on the network.

From the “Access Control” tab of the dialog box, the user selects the security type. For a small peer-to-peer network, share-level access is adequate. This allows printers, hard drives, directories, and other resources to be shared and enables the user to establish password access for each of these resources.

In addition, read-only access allows users to view (not modify) a file or directory. To allow a printer to be shared, for example, the user right-clicks on the printer icon in the Control Panel and selects “Sharing” from the drop-down list. Next, the user clicks on the “Shared As” radio button and enters a unique name for the printer.

If desired, this resource can be given a password as well. When another computer tries to access the printer, the user will be prompted to enter a password. If a password is not necessary, the password field is left blank. Another security option in the “Access Control” tab is user-level access, which is used to limit resource access by user name.

This function eliminates the need to remember passwords for each shared resource. Each user simply logs onto the network with a unique name and password; the network administrator governs who can do what on the network. However, this requires the computers to be part of a larger network with a central server—perhaps running Windows NT/2000 server—that maintains the accesscontrol list for the whole network.

Since Windows 95/98 and Windows NT/2000 workstations support the same protocols, Windows 95/98 computers can participate in a Windows NT/2000 server domain. Peer services can be combined with standard client-server networking.

For example, if a Windows 95/98 computer is a member of a Windows NT/2000 network and has a color printer to share, the resource “owner” can share that printer with other computers on the network. The server’s access-control list determines who is eligible to share resources. Once the networking infrastructure is in place, the NIC of each computer is individually connected to a hub with Category 5 cable or wirelessly via the access point.

This cable has connectors on each end that insert into the RJ45 jacks of the hub and NICs. For small networks, the hub usually will be manageable with the Simple Network Management Protocol (SNMP), so no additional software is installed. Once the computers are properly configured and connected to the hub, the network is operational.

Peer-to-peer networking is an inexpensive way for small companies and households to share resources among a small group of computers. This type of network provides most of the same functions as the traditional client-server network, including the ability to run network versions of popular software packages.

Peer-to-peer networks also are easy to install. Under ideal conditions, installation of the cards, software, hub, and cabling for five users would take only a few hours. Wireless links provide the advantage of mobility within the home or office, allowing a notebook to be used in any room.