March 1998

TELECOMMUTING OVER POTS: YES YOU CAN!

BY PAUL A . KRASKA

While SVD technology has been widely heralded as a solution for higher speed digital communications such as ISDN, the technology is equally sound when used over POTS lines in the telecommuting environment. In fact, POTS SVD is an especially attractive alternative when ISDN is cost-prohibitive or simply unavailable. You don’t need high-speed digital lines to effectively telecommute. While the benefits of POTS SVD telecommuting can be significant, enterprise support systems must address mission-critical issues — or efforts to cost-effectively accommodate remote workers will fail.

SVD (Simultaneous Voice and Data) technology combines voice and data into a single stream of information that can be transmitted over a variety of communications media. The wider the bandwidth of the medium, the more data and voice it can handle. Providing SVD over POTS (Plain Old Telephone Service) lines is the most difficult challenge due to the relatively small band-width available. Two methods have been employed using analog and digital techniques.

Analog Simultaneous Voice and Data (ASVD), transmits voice in its native, analog format and reduces the data rate to provide separate channels for voice and control information. To make room for all three channels, the voice bandwidth is limited to 2400 Hz, and the data bandwidth is limited to 4800 bps.

Invented in 1992 by Multi-Tech Systems for use in modems, Digital SVD, or DSVD, treats all information as digital information. Voice is digitized, packetized, and multiplexed with data packets. While voice packets are given priority over data packets, they are transmitted through the same circuitry as the data. This means that the entire bandwidth of the phone line is used to expedite each packet of data. With DSVD, the bandwidth is allocated dynamically for voice or data. In periods of low voice activity — even as short as a pause between words — the data fills the entire bandwidth available.

"ULTIMATE" TELECOMMUTER
The proper partnering of SVD technology, routers, and software can create an "ultimate" telecommuter system using POTS. A pair of these POTS SVD-enabled routers (Figure 1) can turn a single phone line into the telecommuter’s voice, fax, and data gateway to enterprise resources, such as the LAN, WAN, and/or PBX. Connected to the enterprise PBX via an FXO (Foreign Exchange Office) interface, the central site router also has a standard RS232 plug that can connect to the user’s workstation, which in turn has an Ethernet connection to the LAN. Alternatively, the router can connect to the LAN directly through an Ethernet port for Remote Node operation. Some SVD routers along with their modems can be standalone or rack-mounted, to accommodate many telecommuters in the enterprise.

Through an internal or rack-mounted external modem, the central site router accesses its mate at the remote site over a POTS connection. The central site router connects to the remote workstation, or even to a remote LAN. The router can also be connected to a phone handset and a standalone fax to receive calls and faxes via the central site PBX. The user also may choose to maintain a separate line for voice calls as a back-up, such as a "home" telephone line or a dedicated fax line.

To initiate a telecommuting session, the telecommuter calls the central site modem/router via the handset connected to the remote router. After one ring, the telecommuter hangs up the phone and the central site router returns the call. The modems then negotiate a connection at the highest possible speed and a connection between the remote PC/LAN and the phone/fax equipment is made to the central site PC/LAN and PBX/fax equipment.

Voice communications to the remote site are handled through the PBX just as if the telecommuter was still located at the central site. By picking up the handset on the remote router, one can dial extensions through the PBX, dial an access code to get an outside line through the PBX, and utilize all other PBX features like, conferencing, voice mail, etc.

For all intents and purposes the telecommuter appears to be in the corporate office. Faxes can be received and sent by the fax machine connected to the remote router via a separate phone jack and separate phone extension number.

Data communications are handled through the same modem link between the PCs at the remote site and central site PC or corporate LAN. For instance, one could run a remote control program like PC Anywhere at the remote site and control a host PC at the central site. The central site PC could, in turn, be connected to the corporate LAN to provide access to all services such as e-mail, file servers, Internet access, and mainframe gateways. Another data processing option would be to connect the central site router directly to the corporate LAN via Ethernet. Using that scheme, one then runs a thin client application on the remote PC accessing a Citrix server ICA host on the LAN. Other options include connecting a remote LAN’s PCs to the corporate LAN using standard LAN-to-LAN routing.

Such SVD router technology and applications are clearly worth considering as tools for the telecommuter-enabled call center. Following is a closer look at SVD’s ability to meet the aforementioned mission-critical issues for an enterprise’s telecommuting infrastructure.

EASE OF USE
The standout benefit of using SVD technology for telecommuting is the ability to connect over a standard analog phone line, which is readily avail able and easy to add virtually everywhere. In the U.S., ISDN and other alternatives are more expensive, difficult to install, and frequently unavailable outside of metropolitan areas. POTS SVD makes telecommuting and remote access a possibility for many employees, regardless of their proximity to headquarters.

In addition, remote users can enjoy the convenience of accessing the enterprise PBX fax, data, and voice services as if they were on-site. Calls to their PBX extension ring directly to their remote desk, and faxes can be routed the same way.

To minimize remote administration, IT managers can consider equipping the remote workstation with thin-client applications, when possible. System maintenance and backup should be as automated as possible, with minimal involvement from the remote user. Remote control software can enable the IS department to perform troubleshooting and installations from the enterprise, when necessary.

SVD routers on the market offer various additional features that can make the remote user’s telecommute more convenient, such as integrating billing functions. For example, a system could eliminate the hassles of expense reports and reimbursement checks by ensuring that all connections are initiated from (and therefore billed to) the enterprise PBX. In this model, as indicated earlier, the remote user dials the number accessing the host router and, once the connection is made, ends the call. The host router then calls the only phone number it can: the remote user’s line, which is connected to its remote mate.

INTERACTIVITY
With thin clients and efficient hardware designs, SVD can attain sufficient application throughputs without unacceptable keystroke delay. DSVD technology maximizes data throughput by packetizing voice, data, and control information for transmission across the entire bandwidth. When voice data is not being transmitted, data can be transmitted across the entire bandwidth, achieving up to the maximum speed of the connection (e.g., 33.6 Kbps).

While DSVD maximizes connection speeds, there is no way to avoid a delay during data transmission via remote access in any network model. Powerful hardware on both ends, such as recent-model Pentiums, speed processing and make up for the connection delays, creating a comfortable computing environment for the remote user.

In addition, the trend toward thin client/server computing has delivered many LAN-based applications to market. A thin client installed on the remote desktop greatly reduces the amount of data that has to be transmitted between locations. Java- and Citrix ICA-architected applications allow much of the processing to be performed at the host server. SVD routers should be selected based on their ability to support these thin-client architectures, which are emerging industry standards.

SECURITY
IT managers shudder imagining outside callers having "read and write" access to the enterprise LAN, and with good reason. Proper SVD routers offer various safeguards against hackers, and these safeguards are a mission-critical feature for the telecommuter-enabled call center.

In the model previously mentioned, an incoming call cannot establish a connection. It can only prompt the host router to call one preset phone number: the location of its mate at the remote location. The dial-out phone number can only be manually changed on-site at the enterprise location. Therefore, a hacker’s attempt to penetrate the system would only result in a phone call to the telecommuter’s machine.

In addition, each pair of SVD routers should have unique encryption codes that can only be decrypted by the given router’s mate. Therefore, it is impossible for someone with an SVD router to decrypt the data even without the dial-out safeguard discussed above.

COST
The primary benefit of using SVD routers for telecommuters is that the connection can take place over a standard POTS line, which is significantly less expensive than an ISDN line or other dedicated connection.

Hardware costs include pairs of SVD routers, workstations, modems, and phone and fax equipment at the remote location. Rack-mounted SVD routers may be less expensive to allow multiple telecommuters to access enterprise resources. Telecommuters who infrequently come on-site will not need a dedicated workstation, but can instead connect directly to the LAN.

Depending on the telecommuter’s needs, software requirements may include whiteboarding, video conferencing, mail, and basic office applications, and/or clients to access applications resident on the LAN. A remote control package will allow telecommuters to access any LAN application through their control of a dedicated workstation connected to the LAN.

TELECOMMUTING FOR THE MILLENIUM
As urban areas become more densely populated, commutes become longer, and cities become more polluted, telecommuting is increasingly becoming a model for the turn-of-the-millenium workforce. The flexibility of working at home lets skilled workers feel closer to their families while maintaining high productivity, without the stress of a commute that wastes hours every week. Like comprehensive health care or year-end bonuses, telecommuting has become a valuable benefit that fosters employee loyalty and pride. Enterprises on the leading edge of accommodating telecommuters are respected for their proactive approach to solving the problems of pollution.

The benefits of accommodating telecommuters are well worth the technology investment, especially when the technology is cost-effective, secure, convenient and efficient. Unique among telecommuting-enabled tools, DSVD has the ability to make the "plain old telephone service" a fast, efficient tool for transmitting digital packetized voice, fax, and data across a single analog phone line. Not simply a tool for gaming, video conferencing, and white boarding, DSVD is increasingly being recognized as the next-generation technology for the next generation of business.

Paul Kraska is the product marketing manager at Multi-Tech Systems. For 27 years, Multi-Tech Systems, Inc., has provided innovative data communications technology solutions to customers world-wide. Multi-Tech Systems is an ISO 9002 certified manufacturer of its state-of-the-art MultiModem line of dial-up communications products. Multi-Tech Systems also provides a host of other products which include ISP/intranet communications servers, data/fax modems, MultiMux voice/data/fax statistical multiplexers, FRADs, DSUs, multi-user serial interface systems, telecommuting communications systems, LAN/WAN connectivity products, and the MultiModemPCS, a voice/data/fax personal communications system with patented simultaneous voice/data transmission (DSVD) capability. For more information, contact the company at 612-785-3500 or 800-328-9717, or visit their Web site at www.multitech.com. 

BY BRUCE THOMPSON

With the growth of mobile work forces and increased telecommuting, the demand for networking solutions that provide remote dial-up access to the corporate LAN, Internet, intranet, BBSs, and other on-line services has rapidly increased. According to International Data Corporation, a leading network analyst, a 10-fold growth in the remote access marketplace will occur over the next few years.

To handle the increased demands for remote access, MIS managers and corporate IT specialists are shopping for inexpensive remote access solutions that are fast, extensible, cost-effective, and easy to integrate with the enterprise LAN. The remote access industry is rapidly evolving to meet those needs. Because they reduce the cost of remote access ownership by making it easier to install, maintain, and integrate with the enterprise LAN, open Windows NT-based PC solutions are quickly replacing many proprietary closed-box remote access installations.

Why Open Systems?
Most of today’s legacy remote access systems are implemented as standalone boxes with proprietary backplanes, network interfaces, operating environments, and remote access software. Once purchased, customers are locked into a single vendor, and heavily dependent on that vendor for installation, integration, and maintenance support. Customers end up paying a premium for this cradle- to-grave support, not only in terms of cost, but in scalability and functionality.

Open system solutions foster competition and economies of scale that not only drive costs down, but give remote access users early access to best-of-breed technology. Open systems solutions are also more scalable, employing standard hardware and software interfaces that make it easier and less expensive to increase remote access capacity and add new functions.

Remote access solutions based on open systems are also easier to install, maintain, and integrate with the rest of the enterprise network. Because most IT departments are already familiar with PC servers and Windows NT tools, no additional training is required to add remote access. Together, these factors result in a lower overall cost of ownership for remote access servers based on open PC platforms.

Windows NY And Remote Access
PCs running Windows NT are fast emerging as the platform of choice for open systems remote access servers. In a recent survey of Fortune 1000 companies, Sentry Market Research discovered that one half had chosen PCs with Windows NT for server deployment. It’s only natural that MIS/IT managers want to leverage this installed base and their familiarity with the Windows NT platform when adding remote access.

From a hardware standpoint, a PC’s standard system bus interfaces (ISA and PCI, for example) give integrators instant plug-and-play access to all the third-party modem, ISDN, and other LAN/WAN options needed for adding remote access to a Windows NT server. And unlike proprietary servers, which vary in size and shape, PC servers can be mounted in traditional racks that are easily scaled.

From a software standpoint, using Windows NT as a platform for remote access servers has several advantages. First, it reduces cost by eliminating the need to develop and maintain a proprietary operating system. Second, it simplifies remote access software development and integration with the rest of the enterprise network.

Because Windows NT is already equipped with standard Routing and Remote Access Services (RRAS), integrators don’t have to develop custom remote access software. For MIS/IT managers, adding remote access is as simple as running an installation utility that tells Windows NT the number of remote access modems and their location. Once this information has been conveyed to Windows NT, system administrators gain immediate access to the remote access subsystem and relevant databases via existing NT tools.

Windows NT RRAS enable servers to field incoming calls from clients running a variety of operating systems, including Windows 95, Windows for Workgroups, Windows NT Workstation, Unix, Novell Netware, LAN Manager, OS/2 and Macintosh. Support for TCP/IP also enables Windows NT servers to connect seamlessly to standard LANs like Ethernet, Fast Ethernet, FDDI, and Token Ring, all of which are available with TCP/IP support. And the Windows NT Multiprotocol Router, which supports TCP/IP, AppleTalk, and Novell IPX/SPX, eliminates the need for a dedicated LAN-to-LAN router

Installation And Integration
One of the key advantages of utilizing Windows NT RAS in a remote access server is greatly simplified installation. All told, an MIS/IT professional familiar with Windows NT server operation should be able to install and integrate an open systems remote access solution with the corporate LAN in less than an hour. And once installed, the remote access connections become immediately visible and accessible to the enterprise-wide NT network administration software.

Suppliers of proprietary legacy remote access equipment may be reluctant to adopt open systems approaches that impinge on their high profit margins. But the advantages of open systems, including reduced cost of ownership, increased flexibility, simplified integration, and timely access to new technology, makes the move to open systems inevitable. For remote access, the platforms of choice will be PCs running Windows NT

Bruce Thompson is the data communications product manager at Ariel Corporation. Prior to Ariel, he was the director of marketing at Spectron Microsystems, a division of Dialogic Corporation. Ariel Corporation offers high-density and cost-effective remote access data solutions for open systems platforms. The company’s high-density RAS-CAL, T1-Modem+, and T1-Modem PC-based modem pools, which support 56 Kbps, V.34+, and ISDN remote access sessions, connect to T1, E1, ISDN, and POTS lines. Ariel’s remote access products target open systems servers spanning a broad range of applications, including telecommuting, Internet access, corporate Intranet and Extranet access, on-line services, transaction processing, and unified messaging. For more information, contact the company at 609-860-2900 or visit their Web site at www.rascal.com.