These days, modems are used primarily to dial into Internet Service Providers (ISPs), but they still have other uses as well. In addition to Dial-up Networking (DUN), that enables you to connect to remote servers using a modem and a telephone line, Windows 98 includes a Dial-up Server that you can use to host remote dial-up sessions. With this arrangement, a user can dial into a system on your network from the Windows 98 computer in his home or using a laptop while traveling.

Once connected, the remote system can access not only the resources on the host system (the computer running the server software), but the other systems on the network as well. With additional software, it is even possible to use the network as an ISP and access the Internet through the router on the LAN. This chapter examines the installation and configuration procedures for these modules as well as some of the ways in which you can make use of Windows 98's remote access capabilities.

Windows 98's Dial-up Networking is an extension of the operating system's networking subsystem. Unlike older operating systems in which modem communications were provided by separate terminal applications, Windows 98 can use a modem as a substitute for a network interface card and assimilate it into the other network components. When you install a modem in Windows 98, a Dial-up Adapter driver appears in the Network Control Panel's components list. Like any other adapter driver, the Dial-up Adapter is bound to protocol drivers, clients, and services, so that network traffic can pass through the host system to the remote workstation.

The Dial-up Server feature in Windows 98 is essentially a scaled down version of the Remote Access Service (RAS) included in Windows NT. The two main differences between them are as follows:

Because of these limitations, Windows 98 can function adequately as a dial-up server for a single machine, but tends to be an impractical solution for multiple remote clients. You can configure several machines on your network to host remote clients, but each one will require its own modem and phone line if users are to connect simultaneously.

When a remote system connects to a Windows 98 host server, the host's drive and printer shares become available to the remote system, subject to the same security limitations imposed on local network users. The Windows 98 machine can also function as a router to the rest of the network, as long as all of the required conditions are met. When this is the case, all of the computers on the network appear in the Network Neighborhood on the remote system, and the user can map drives and access shares just as he would on a local network. The only difference will be that network access from the remote machine is slower (maybe much slower) than a local one, because the modem connection runs at nowhere near the speed of an Ethernet LAN.

In order to access the network from the remote location, all of the computers involved must be running either the NetBEUI or IPX protocols, including the remote and the host system, as well as the other computers on the network. On a typical home or small business network, you may be running NetBEUI already, but if not, you can install it along with TCP/IP or any other protocol.

Windows 98 is deliberately designed not to route IP traffic between the LAN and a Dial-up Networking connection. The Internet Connection Sharing feature included in Windows 98, Second Edition does provide limited IP routing capabilities. However, for remote network access, NetBEUI or IPX is required unless you use a third-party routing program.

In order access your network from a remote location, you must equip one of your Windows 98 machines with a modem and a phone line that will not be in use during the times that you want to connect. You can use the same modem to connect the network to the Internet during the day and leave the line open to receive incoming client connections at night. It is also possible to connect two modems (with two separate phone lines) to one machine, but you can only use one of the two as a Dial-up Server.

The Dial-up Server can be installed with the Windows 98 operating system along with Dial-up Networking, or at any time afterwards from the Windows Setup page in the Add/Remove Programs Control Panel. In the components list, choose Communications and fill the Dial-up Server checkbox (as well as the Dial-up Networking box, if it is not already checked). Installing this module adds a Dial-up Server item in the Dial-up Networking window’s Connections menu, which displays the dialog box shown in Figure 13-1.

When the Windows 98 system is configured to use share-level access control, as it is on a workgroup network, you activate the server by selecting the Allow Caller Access radio button and using the Change Password button to protect the system against unauthorized access. Any user with the password will be able to access the system by connecting with a modem, so you should be sure to use a strong password here.

The Server Types dialog box (see Figure 13-2) enables you to specify the type of clients that will be connecting to the machine. The Dial-up Networking clients in Windows 95 and 98, Windows NT 3.5 and higher, and Windows 2000 all use the Point-to-Point Protocol (PPP) to connect to servers, by default. Windows NT 3.1 and Windows for Workgroups do not use PPP. If you connect to a Windows 98 Dial-up Server using these clients, you must use the NetBEUI protocol on all of your network systems in order for the remote client to access them. The Default server type enables the server to support clients using either PPP or NetBEUI. From this dialog box, you can also monitor the server connection and disconnect the user that is currently accessing the system.

Once you enable the Dial-up Server, the modem will answer the phone any time it rings, usually by the second ring. The Dial-up Server provides only the most basic modem control capabilities. You cannot, for example, specify how many times the phone should ring before the modem answers, or impose greater security on the connection by allowing only specific users to connect to the system. User-level access control is available in Windows 98’s Dial-up Server, but only if you are running a domain on your network, which requires a Windows NT server.

When you install Dial-up Networking on any Windows 98 system, in addition to adding the Dial-up Adapter driver, the system binds all of the protocols installed on the system to the new adapter. By default, any other protocol modules that you add to the system are automatically bound to all of the adapters, including the Dial-up Adapter. A protocol must be bound to an adapter for traffic using that protocol to pass through the adapter.

By opening the Properties dialog box for an adapter and looking at the Bindings page, you can specify which protocols should be bound to a particular adapter. If, for example, you use Dial-up Networking only to connect to an ISP, you can unbind the NetBEUI and IPX protocols from the Dial-up Adapter (if they're installed), because the Internet uses only TCP/IP. If you later want to use the system as a Dial-up Server to grant a remote user access to the network, you must re-bind NetBEUI or IPX to the Dial-up Adapter. Although the remote user can access the host system's resources using TCP/IP, it will not be able to access resources elsewhere on the network.

Dial-up Networking is installed on a Windows 98 system by default during the modem installation process, so that even a system that is not connected to a LAN will have a network protocol stack. In most cases, Windows 98 will be able to identify the type of modem installed on the computer and will configure itself accordingly. Once Dial-up Networking is installed, you can use the Make New Connection wizard to create the DUN profile that you will use to connect to the Dial-up Server.

The Make New Connection wizard creates a default profile using the connection name, modem, and phone number you specify, but you can modify other parameters by opening the Properties dialog box for the connection. On the Server Types page (see Figure 13-3), you can activate the following features:

• Log on to network – Causes the DUN client to log the system onto the network once the connection is established, using the account name and password used when logging on to Windows 98. When you are connecting to a workgroup network that uses share-level access control, this option is not necessary, because access to network resources is provided through individual share passwords.
• Enable software compression – Enables the system to send data over a PPP connection in compressed form, thus increasing the efficiency of the connection. In order for compression to occur, the Dial-up Server must also have the Enable Software Compression option enabled in the Server Types dialog box. If one of the two systems does not have compression enabled, the connection will still be established, but software compression will not occur. Most modems today provide some form of hardware compression, which provides the same result as DUN's software compression on the modem-to-modem link. However, DUN's software compression reduces the amount of data sent from the computer to its modem, which provides a slight increase in efficiency. (Note that data cannot be compressed twice; once it is compressed by the DUN software, the modem hardware cannot compress it further.)
• Require encrypted password – Forces DUN to use the Challenge Handshake Authentication Protocol (CHAP) when connecting to a server, which transmits all passwords in encrypted form. By default, a Windows 98 machine will use always CHAP when connecting to another Windows 98 machine, no matter what the setting of this parameter. However, when this option is disabled, DUN is also capable of using the Password Authentication Protocol (PAP), which transmits passwords in clear text. The Server Types dialog box on the Dial-up Server also includes a Require Encrypted Password option, which you can use to allow connection only by client systems using CHAP.
• Require data encryption – Causes the connection to transmit all control and user data in encrypted form. This option is used when establishing a virtual private network (VPN) connection to a server. A VPN connection uses a special protocol called PPTP (the Point-to-Point Transfer Protocol) to transmit data over the Internet (or another public network) securely. The Windows 98 Dial-up Server is not capable of functioning as a PPTP server, so this option should not be used for Win98-Win98 connections.
• Record a log file for this connection – When activated, the system creates a log file in the C:\Windows directory called Ppplog.txt and records all of the activities involved in the establishment and termination of the connection.

This dialog box is also where you select the protocol(s) that the system should use when connecting to the Dial-up Server. The server can establish a connection using any of the protocols that are bound to the Dial-up Adapter in the Network Control Panel. On the remote system, the protocol(s) you want to use must be selected in the Server Types dialog box and also be installed and bound to the Dial-up Adapter in the Network Control Panel.

If a user receives an Error 720: Dial-up Networking could not negotiate a compatible set of network protocols you specified in the Server Type settings message while trying to connect to the server, examine the following three places to see if they have the correct protocols in common:

For network access through the DUN connection, include NetBEUI in your protocol selections. IPX will work as well but, as mentioned elsewhere in this book, is needed on a Microsoft network only if Novell NetWare servers are also present. If you want to restrict a remote user to the resources on the Dial-up Server system, bind only the TCP/IP protocol to the Dial-up Adapter and configure the DUN client to use TCP/IP only.

The TCP/IP Settings button displays a dialog box in which you can specify the IP and name server addresses that the system will use when connecting to the host, but for a Win98-Win98 connection, this isn't necessary because the remote system will only be accessing the server's shares. The systems will essentially create a two-node network, and the Dial-up Server will assign the IP address 192.168.55.2 to the remote system.

Once you've configured the DUN connection, you can connect to the Dial-up Server. As always, the Connect To dialog box requires a user name and a password for the connection. The password must be the same as the password you specified when configuring the Dial-up Server. The user name is not relevant, as you'll be using share-level access passwords for all of the resources at the host site.

If you do not enter a password, or if you enter the wrong password, DUN will prompt you for one after the connection is established. This time, the dialog box has fields for a user name, password, and domain, but only the correct password is needed.

With the exception of the status line in the Dial-up Server dialog box, there is no indication on the host system that a remote user is connected (except for tell-tale disk accesses, flashing modem lights, and so on). If the Dial-up Server dialog box shows that a remote user is connected, the host can disconnect him using the Disconnect button in that dialog box.The remote user can sever the connection using the DUN icon in the system tray.

Oncea user has successfully logged on to the Dial-up Server, he can access the shared drives and printers on the server and other network machines just as if the computer was directly connected to the LAN. He can use the Windows 98 Explorer, Network Neighborhood, or the Run dialog box to open a share window, in the normal manner. If passwords are required to access specific shares, Windows 98 will prompt for them and deny access if the wrong (or no) password is specified.

Windows 98's DUN is a remote networking product that enables a computer at another location to participate on a network as though it were directly connected. When you connect to a Dial-up Server, you are not directly accessing the machine; you are just participating with it, like any other network workstation. You must create shares on the server system in order for the remote user to access its drives.

Shared printers are also accessible from a remote system, although their utility is questionable. If you want to print a document on a printer at another location in order to pick it up later, you will find that it's usually more efficient if you copy the document file to a system on the network and print it when you get there (or have someone do it for you). The output generated by an application when it prints a document is usually much larger than the document file itself, since it includes uncompressed bitmap representations of any graphics and fonts.

If you are running a Microsoft Mail post office on your network, remote users can use Dial-up Networking to access their mail from a remote computer. It is possible to configure the Microsoft Mail service to sense when the post office is not available through a LAN connection and to use a specific Dial-up Networking profile to access it. When working from home or when traveling, this can enable users to keep in touch with the office at their convenience.

To configure a system for remote email access, create a DUN profile and set up a Dial-up Server on the network, just as for normal remote access. The rest of the configuration parameters are located in the Microsoft Mail Properties dialog box, which you access from the Mail and Fax Control Panel or by selecting Tools/Services in Windows Messaging or Outlook 97. The basic mail configuration parameters, such as the location of the post office and the mailbox name and password, are the same as if the computer was connected directly to the LAN.

On the Connection page of the Microsoft Mail dialog box (see Figure 13-4), you select how the computer will connect to the post office, and the setting you choose for this should depend on the computer you're using for remote access. If you're working from home, select Remote Using a Modem and Dial-up Networking, so that the system will immediately connect using DUN. If you are using a laptop that may be connected to the LAN or that may be in another location, use the default setting: Automatically Sense LAN or Remote. This causes the program to try to find the post office on a connected LAN and, if it fails, uses a DUN connection.

There are two ways to access your email using DUN; either connect to the post office using an already-opened DUN connection, or configure the email client to trigger a new connection. When a user launches Windows Messaging or Outlook 97 while already connected to the network using a DUN connection, the program considers the computer to be attached to the LAN because the post office is immediately available. In the Microsoft Mail service is configured to automatically sense the LAN, it will connect to the post office by itself and access the user's mail as though directly connected to the LAN. If the computer is not connected to the LAN, either directly or through DUN, when the user launches Windows Messaging or Outlook 97, the system will not be able to locate the post office and will use DUN to connect to it.

When using Outlook 97 to launch a DUN connection to the network where the post office is located, users have the option of using Microsoft Mail's Remote Mail feature. Remote Mail enables the user to control the amount of data that passes over the modem connection, so that he can avoid wasting time transferring emails he doesn't need. When the user retrieves mail from the post office using Remote Mail, the client program actually downloads only the mail headers, and not the actual mail messages (and attached files) themselves. The program then displays the headers in the Inbox window. The user can look at the headers and decide from the Subject and From fields which emails he wants to read and mark them for retrieval. Skipping unimportant emails or those with large attachments minimizes the time spent connected to the network.

To use Remote Mail, open the Microsoft Mail Properties dialog box from the Mail and Fax Control Panel, and select the Remote Configuration page shown in Figure 13-5. The Use Remote Mail checkbox prevents the program from automatically sending and receiving all of your mail when the user connects to the post office, enabling him to connect only when he chooses to do so. The Use Local Copy checkbox causes the program to use a copy of the post office address book that has been downloaded to the workstation, so that the user doesn't have to access the address book from the server each time he opens it. Notice that there is also a LAN Configuration page in the dialog box containing the same settings. These are applied only when the client is connected to the post office directly through the LAN.

The Remote Session page in the same dialog box (see Figure 13-6) enables the user to specify when the program should initiate the DUN session and when it should terminate it. The user can configure the service to connect to the network automatically when he launches the email client, or to wait until he specifically instructs it to connect. To minimize the connect time, avoid having the client launch the connection automatically. The user can work in the client program offline, to compose and respondito messages, and then store them in the Outbox until it’s time to connect to the network and deliver them. From this page, he can also schedule mail deliveries to occur specific intervals, so that the client automatically retrieves mail on a regular basis.

The Dial-up Networking page (see Figure 13-7) specifies which DUN profile the client should use to connect to the network, how often it should retry if the connection attempt should fail, and whether the program should prompt before connecting.

Once the user has configured the service and launched the email client, the program goes into remote mode (assuming that it cannot connect to the post office). Depending on how it's configured, the program may use DUN to connect to the network immediately or wait until instructed to do so. At this time, the user can compose new mail or work with messages he's already downloaded. When the user wants to connect to the post office, he can use the Remote Mail commands in the Tools menu, as shown in Figure 13-8.

When the user selects Connect from the Remote Mail submenu, the program launches the Remote Connection Wizard and compiles a list of actions to perform, like that shown in Figure 13-9. If, for example, there is outgoing mail waiting for delivery in the Outbox, a Send event will appear in the list. The Retrieve New Message Headers via Microsoft Mail event is always present. The user fills the checkboxes to select the activities he wants to perform during that session, deferring the others until later.

When the user downloads message headers from the post office, they appear in the Inbox with an icon identifying them as headers and not complete messages. After deciding which messages he wants to download, he marks them by selecting either Mark to Retrieve or Mark to Retrieve a Copy from the Remote Mail submenu. By retrieving a copy, the original message is left in the post office mailbox, so that the user can retrieve it again. If he's on the road and checking mail with a laptop, the user might want to retrieve copies so that he can download the messages again later from his office machine, in order to save them in his personal folders.

The next time the user connects to the post office, Retrieve events for the messages he's marked appear in the Remote Connection Wizard's list. Retrieving them creates new items in the inbox, which this time consist of the entire message, and not just the header. The user can then disconnect from the post office, create responses to the messages at his convenience, and reconnect to upload his replies.

The remote network access provided by DUN is good for tasks that don't usually require large data transfers, such as transferring small files and checking email,. However, even basic tasks like these can be infuriatingly slow over a modem connection. The maximum connection speed of a standard modem is 53 Kbps, and even that is rare, while an Ethernet LAN routinely operates at 10 Mbps (or 10,000 Kbps). Obviously, this difference in speed is going to be reflected in the system's network performance. Data intensive tasks like running a large application from a server drive are out of the question during a remote networking session, as simply transferring the program files required could take an hour or more.

It is possible to open a document on a network share from a remote system and edit it, but saving changes will take much longer than it does on the local network. If the application is configured to automatically save the document every so often, the delays may be frequent. In most cases, it's better to copy the file to a local drive first and edit it from there, though you must remember to copy the modified version back to the server before you log off.

Remote network access is not the only method of accessing network data from a remote location, although it is the only method directly supported by Windows 98. It is also possible to access a system on a network from another location using a remote control application, such as Symantec's pcAnywhere. Unlike remote network access, a remote control application enables you to actually operate a PC on the LAN from a computer connected using a modem.

Dial-up Networking uses the host system on the LAN as a router. If you launch a program from a network share, the program files are downloaded to the remote machine and executed by that system's processor. With remote control, you are using the monitor, mouse, and keyboard of the remote system to control the host computer on the LAN. What you see on the monitor at the remote location is identical to the display on the host machine. When you launch a program, it is the processor in the host system that executes it, not the remote system's processor. Thus, the data passed between the remote system and the host is composed primarily of display data and keyboard/mouse input signals, not actual program and data files. The system response time is still far slower than that of a computer using an Ethernet connection to the LAN, but the amount of data transferred over the modem connection can sometimes be far less than in remote network access.

Remote control solutions also usually include the ability to transfer files between the host and the remote systems, but for these processes, the product offers no advantage over DUN. If, however, you have to execute a network application that would require the transfer of large program and data files in a remote access situation, remote control might be a preferable solution.

Another limitation of Windows 98's remote network access capabilities has already been mentioned: the lack of IP routing capabilities. Since a Dial-up Server cannot route IP traffic, you cannot access a intranet server from a remote workstation, nor can you access the Internet through your LAN. However, there are products on the market that add IP routing capabilities to Windows 98.

NAT32, by ACT Software, is a network address translation server product that enables you to connect your home or small business network to the Internet using a shared dial-up or cable modem connection. Chapter 10, Accessing the Internet, discusses network address translation, among other Internet access strategies.

You can configure NAT32 to function an as IP router that works with Windows 98's Dial-up Server to provide access to the intranet servers on a LAN, as well as to the Internet, using the LAN's ISP connection. You may, for example, have a full-time, high speed Internet connection in your office using a cable modem or xDSL, that remains unused during non-business hours. Rather than pay for another Internet connection for your home, NAT32 enables you to dial into a workstation on the office LAN using a standard Dial-up Networking connection and use the high speed connection installed there. You will still be limited by the speed of your modem connection to the office, but the performance will be at least as good as a dial-up connection to an ISP, it will cost you nothing after you buy the NAT32 software, and you will never get a busy signal.