Product Reviews

Network Card with a Brain

New Etherlink card saves CPU cycles.

If you’ve been around the PC business for a few years, you may recall the revolution in graphics cards that happened when the first accelerated graphics cards were introduced. Recognizing that displaying complex graphics was a computation-intensive process that didn’t interact much with other parts of modern software, these cards included their own microprocessors to take over part of the load from the CPU. The success of this approach can be measured by noting that it’s hard to buy a system without such a graphics card today. Now, 3Com (in partnership with Microsoft) is trying to do the same for network operations.

The first fruit of this partnership is the 3CR990 family of network cards, with an integrated processor that 3Com has dubbed the 3XP. For this review I worked with the 10/100 PCI 10BaseT version of the card on a Win2K system. Indeed, if you’re not running Win2K, you probably don’t want to spend the money on this card. That’s because it’s designed to work with new APIs in that operating system that allow the CPU to offload two critical networking operations: TCP segmentation and IPSec.

TCP segmentation is a process that goes on whenever a computer wants to send a large data block over TCP/IP. Because Ethernet frames are limited to 1513 bytes, large blocks must be broken up into multiple smaller frames, each with its own header information. The 3CR990 allows the CPU to send the entire block of data to the network card, and then the network card itself handles the segmentation of the data into frames.

IPSec is a standard for TCP/IP security supported by Win2K that encrypts data sent over the network with 168-bit DES. While Win2K can accomplish this entirely within the operating system, it can take a lot of CPU cycles to do so. The 3CR990 implements the DES algorithm in its own firmware, allowing the CPU to just send the data and handling the encryption and decryption on the network card itself. 3Com says that this can lower the CPU load for IPSec by 33 percent. Because the card implements this strong algorithm, it can’t be exported outside the U.S.A. and Canada (there’s also a 56-bit version that is export-legal).

The card installed easily in my test system, although it required installing drivers after the operating system was installed (this may be because I was using a late beta version of Win2K) rather than as part of the hardware-detection process. Once installed, that was it: no problems whatsoever. Turning on IPSec is as simple as choosing one option in TCP/IP properties, and the card communicates fine with everything else on my network, encrypted or otherwise. At a street price of about $100, this card is worth a serious look by anyone planning a new Win2K-based network who’s concerned about data security.

About the Author

Mike Gunderloy, MCSE, MCSD, MCDBA, is a former MCP columnist and the author of numerous development books.

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