Originating publication
September 07, 1998, Issue: 806
Section: News

CRN Test Center Analysis -- The BayStack 660 Serves Up Wireless Freedom
New York -- With many emerging markets going completely cellular to deploy telecommunications networks, it is clear that wireless access means freedom. Bay Networks Inc. delivers its take on cordless freedom for office workers with its wireless LAN offering, the BayStack 660 DS.

Developed through its acquisition of Netwave Technologies last June, this wireless LAN (WLAN) allows workers to roam through an office building with continuous, nonstop network access.

While the PC Card part of the system costs a steep $569 each, this product can offer significant cost savings when highly paid knowledge workers are considered.

A Wireless LAN Alliance return-on-investment study found the payback period for a wireless LAN can be as short as four months and provide an average ROI of $17,354 per user.

The CRN Test Center was so impressed with this technology and the ease of use and performance of the BayStack 660 that it is now planning on doing a review of WLANs next year.

Installation was a breeze. Windows 95 and 98 automatically detected the WLAN PC Card. After the drivers were loaded, the only task necessary was to assign a new network ID using the Network Properties option in Windows.

Resellers may be unaware of the IEEE 802.11 standard for WLANs. This makes the technology an open standard. WLAN Cards communicate with Access Point (AP) hubs, with each AP supporting up to 50 simultaneous connections, depending on the application.

For light traffic applications, such as E-mail or telnet, all 50 available connections can be used. For normal traffic levels, such as Web access or database applications, resellers should expect 10 to 20 simultaneous users.

The BayStack 660 uses the Direct Sequence (DS) spread spectrum and the 650 uses Frequency Hopping (FH) spread spectrum, both of which use the 2.4GHz radio frequency band. This band is available worldwide for unlicensed operation and is capable of operating at LAN speeds.

Using multiple APs throughout a building or campus creates contiguous wireless access as the APs seamlessly hand off to one another. To support areas of high user density and/or network traffic, the APs can be overlapped to increase aggregate WLAN bandwidth. Each AP creates an independent WLAN segment, analogous to segmentation in Ethernet networks Contention is reduced by the balancing of the load among multiple APs. In essence, the load balancing process is completely automatic and transparent.

The CRN Test Center examined the DS spread spectrum BayStack unit, which offers the highest performance, with a 2-Mbps data rate and a range of 200 to 300 feet in an office environment and up to 2,000 feet in an open area. The BayStack 650 uses FH spread spectrum, which offers about half the performance of the BayStack 660 product.

The advantage of the FH specification is higher scalability with as many as 10 APs overlapping compared with the limit of three APs for DS. As such, FH devices are generally seen in areas of high-user density such as a trading floor, lecture hall or laboratory. Unfortunately, these technologies are not interchangeable-a FH PC Card cannot talk to a DS AP.

The system also can be used in what is called ad hoc mode, in which laptops equipped with BayStack 660 wireless LAN adapters can connect to one another without the use of an Access Point. The BayStack Series 600 APs are SNMP-manageable allowing the management information to be included in all standard SNMP management systems.

A Java-based management utility allows resellers to easily configure and upgrade all APs on a given network. A Windows-based utility included with the product allows resellers and administrators to survey the environment during the design and planning stage.

In this age of 100-Mbps and gigabyte networks, 1 to 2 Mbps sounds rather slow but it is all a matter of perception. Ethernet is a shared medium and each user's share of bandwidth is far less than the 10, 100 and 1,000 Mbps that the medium can theoretically support. When compared with the 1.5-Mbps throughput of a T1 line that often supports an entire organization, the performance of the WLAN technology seems rather good.

The Test Center's analysis found the throughput of the BayStack 660 to range between 1 Mbps and 1.2 Mbps. Throughput is the measurement of the time to transfer the actual data, while data rate includes the actual data and the network overhead.

The CRN Test Center recommends the BayStack 660 DS from Bay Networks Inc.