2-7 Remote LAN Access Technology
MICHAEL VAN PATTEN
Now that it is common for executives and professionals to travel with portable computers, it is necessary to maintain remote communications with an organization's computer networks. Downsizing of mainframe computers has led to large local area networks (LANs) throughout both the public and the private sectors. These LANs contain the information data bases that facilitate the execution of the organization's strategy and tactics.
Quick and easy access for mobile users is a requirement as they try to connect to their corporate networks from hotels and airports. This access must also be secure from unwanted intruders and hackers who might try to break the integrity of the system. Remote dial-in access allows mobile users to continue working while traveling outside their office environment.
REMOTE ACCESS METHODS
There are two major modes of remote LAN accessremote control and remote node (see Exhibit 2-7-1). Remote control and remote node have distinct differences in their communication activity and application performance. Only one mode can be used by a remote user at one time.
Exhibit 2-7-1. Remote Access Methods
Remote access can be performed several other ways, including LAN-to-LAN access, remote routing, and border routing. However, only remote control and remote node methods and products are discussed in this chapter.
Remote Control Access
With remote control access, the remote user connects to a workstation on the LAN and takes control of its operation. The software on the remote system sends keyboard commands to the workstation and the remote system receives screen images from the workstation. The LAN actually communicates to the local workstation while the remote control software communicates to the remote system. All the actual processing is performed on the local LAN workstation. Only the resulting screen image is transmitted to the remote computer.
Generally, this type of access occurs through a modem on the workstation over the telephone line to a modem on the remote system. However, this communication can occur over the LAN either to another local workstation, or through a communications server that has a modem connecting to the remote system through the telephone line.
Modems
Today, modem technology is characterized by rapidly increasing speed and rapidly decreasing prices. The past standards of 14.4K bps and 28.8K bps have been replaced by faster technologies. The most popular modems today operate at 33.6K bps or 56K bps. Dedicated lines such as T1 handle speeds of 1.544M bps.
Remote Node Access
The second method of remote LAN access is called a remote node connection. A remote system connects to the LAN through a communications server and directly communicates to the LAN with a LAN node address. The remote user can access data files, use the LAN print servers, and call up LAN-based applications. Actual network packets are transmitted to the remote computer as if it were locally connected. The LAN views the remote system as a node like any other local node on the network.
APPLICATIONS
Personal productivity tools were the first applications to revolutionize the computing world. These tools include word processors, spreadsheets, data bases, and presentation generators. As computer users connect their systems through networks, they need to perform more than just personal applications. Many of these newer applications are considered group productivity applications, or groupware.
Electronic Mail
Electronic mail, or E-mail, was the first successful major group application. This application allows users to communicate more often and to more people. E-mail delivers messages faster than any other methodology. E-mail users can organize their communications better, reply to requests immediately if desired, and forward information more easily than through conventional written correspondence.
There are three methods to obtain E-mail remotely: through remote control access, through remote node access, or through an E-mail server (see Exhibit 2-7-2).
Exhibit 2-7-2. E-mail Connections
Remote Control E-mail Access
Through the use of remote control, a remote user can connect to the LAN and have the controlled workstation log into the LAN and execute the E-mail application. The user can read the E-mail by sending keyboard commands to the controlled workstation. E-mail is often more than just text, however. When E-mail contains multimedia objects, network performance can be slowed considerably.
Remote Node E-mail Access
The second method of obtaining E-mail from a remote system is through remote node access. The remote system connects to the communications server on the LAN and logs on. Then the remote system executes the LAN-based E-mail application through the telephone connection. Using commands in the E-mail application, the remote user can download any E-mail messages waiting to be read. In addition, the remote user can write E-mail messages and send them back through the telephone line to the LAN for storage.
E-mail Server Access
A third method of obtaining E-mail remotely is through an E-mail server. The remote system dials directly into a dedicated E-mail server. The server verifies the user, immediately downloads any unread E-mail messages to the remote system, accepts any new E-mail from the remote user, and then hangs up to minimize telephone line charges.
Newer E-mail clients are beginning to offer a slight variation on this method, retrieving only the header information from each message. This option gives the user the capability of determining which messages to retrieve, which to delete without reading, and which to save for later retrieval (presumably after the user is connected locally). This approach can save considerable amounts of time, especially when messages contain large attachments.
Field Force Automation
Another application being implemented across many types of organizations is field force automation. Typically, field personnel are outfitted with a portable (laptop or notebook) computer with a modem, customer tracking or order entry application software, communications software, and communications servers at the office.
IDC (Framingham MA) performed a survey of more than 400 midsize US organizations that had implemented field force automation and found that 60% of those companies had met or exceeded their expected goals. Their measurable results included reduced order processing time, increased revenues and profits, improved revenue per employee, and faster competitive feedback. The average cost of automating a salesperson was less than 1% of the person's average salary and overhead.
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