US Robotics 802.11g Wireless Turbo Multi-Function Access Point
October 08, 2003
100Mbps? 100% faster? Hardly. If you're willing to make an investment in only TI-based 802.11g products from US Robotics, this access point may indeed reap some benefits but the high price and lack of new security standards (WPA) prevent it from being a must have.
Reading the packaging and various materials that come with the new US Robotics Wireless Turbo Multi-Function Access Point, you might be forgiven to think that the product was the best thing to happen to wireless since the invention of AM radio. With copious use of terms like "100% faster", "100 Mbps", "Turbo", and "Accelerator" the claims seem audacious even by marketing standards.
The main claim to fame of the 5450 is that it's one of the first products to utilize the new TNETW1130 802.11g chipset from Texas Instruments <QUOTE NYSE:TXN>. After nearly nine months of 802.11g product availability and over three months after the standard was ratified, yet another 802.11g chipset would seem to be a yawn inducer. What's supposed to make this particular slab of silicon noteworthy is the fact that it's the first 802.11g product with native support for Packet Binary Convolutional Code (PBCC) modulation, the technology used in 22 Mbps (802.11b+) hardware. TI had lobbied unsuccessfully to have PBCC modulation included in the final 802.11g standard, but it was defined as an optional modulation technique.
The "Turbo" refers to TI's packet aggregation mode, which aims to improve performance by streamlining the transmission of packets. The frame bursting feature of previous chipsets aim to improve performance by sending more than one packet before requiring an acknowledgement by the recipient. The TI approach optimizes throughout by combining multiple packets in to a larger packet with a single header, thereby reclaiming some of the bandwidth consumed by network overhead and putting it to use moving actual data. It's a different means to the same end.
But what about claims of "100 Mbps" and "100% faster"? Read on to see if the product lives up to its boasts.
The $209.95 (street price) USR5450 is housed in a diminutive black plastic case. With its low profile and extremely tall antennae, the unit almost has a Bugs Bunny look to it. The 5dBi diversity antennae are of the tilt and swivel variety, removable via reverse SMA connectors.
Like many previous US Robotics (USR) products, the USR5450 has a 9-pin serial port on the rear of the unit for direct configuration. In addition to the obligatory browser-based configuration method, you can also access and modify the unit via Telnet. On my test unit, the AC adaptor plug fit into the USR5450 very poorly, and in fact came loose on more than one occasion. Hopefully, this was a peculiarity rather than a widespread phenomenon.Most people will likely utilize the USR5450 as straightforward access point, but the unit is versatile enough to function as a bridge, repeater, or even as a client adapter, though I didn't operate the unit in any of these modes since I had only a single unit.
To pick nits for a moment, as someone who hails from the "red lights are bad" school of technology, USR's use of red LEDs (on both the AP and the client card) to indicate normal function is mildly annoying and often still makes me do a double take.
The initial setup of the USR5450 didn't go as smoothly as I would have hoped. USR supplies a configuration utility to locate the access point on the network, but as fate would have it, the software was unable to locate the device on two separate systems and networks, even though it was powered up and properly connected to the network.
The product documentation, which is HTML-based and somewhat difficult to negotiate quickly (a PDF file would have been preferred), did not contain any information about a default IP address for the USR5450. After a few minutes, I discovered that the device was a DHCP client by default, and identified the address it had obtained by checking the assigned address pool on my DHCP server. All's well that ends well, but I wonder how a user might reconcile a similar situation if there was no DHCP server in place, since the unit doesn't configure itself to a static IP in the absence of DHCP. In this scenario, the utility would be only way to access the unit.
Once you get to it, the USR5450 sports the same clear and functional interface US Robotics has used in its previous products. Finding and modifying configuration parameters can be accomplished quickly and easily.
The 5450 provides WEP encryption, and like previous TI-based products, it offers a 256-bit WEP level in addition to the typical 64-bit and 128-bit varieties. For now, WEP is the only way to go--WPA is under development, and is expected to be available in the October 2003 time frame. USR will submit the USR5450 for Wi-Fi certification at that time. Client authentication can currently be done by MAC filtering or via 802.1X with external RADIUS server.
The product provides a rather unique security feature that can be used in association with MAC filtering function. It has a "WARN" LED on the front bezel, which can be configured to illuminate whenever a client with an unauthorized MAC address attempts to associate to the access point. The rationale to provide some kind of visual indication that mischief may be afoot seems reasonable (and the light did flash when my "rogue" client attempted to connect). On the other hand, without an audible warning you have to be looking at the light to notice it, and it could just as easily be set off by passers-by who aren't necessarily attempting mischief, but simply have SSIDs set to "ANY."
On the subject of monitoring, there is a device log, but since it exists only in volatile memory (it can't be output to a file or to a Syslog server) its usefulness is limited. Thankfully, the USR5450 does provide SNMP support for remote monitoring.
The USR5450's radio offers six levels of transmission power ranging from "highest" to "lowest." The fact that "medium high"-- the third level -- was the default setting immediately caught my attention. USR told me that this feature is currently disabled, and that by default it transmits at its full 100mW signal strength. The power levels will be implemented in a later firmware release.