Revenge of the Network Interface Cards

By Kevin Tolly
Network World, 11/13/00

By now, network interface cards were supposed to be absorbed into the PC's system board and be about as exciting as a three-prong electrical plug - but they are back with a vengeance. They've got designs on their host systems. Loaded with processing power, memory and a lot of smarts, the humble NIC has morphed into a PCI-pluggable e-commerce appliance and new source of benefits for customers and revenue for vendors.

While servers have grown in power, software typically succeeds in absorbing much of that power. To that, one can add the load of managing sessions from hundreds or even thousands of simultaneous users. The encryption/ decryption associated with some or all of those sessions adds to the workload.

The e-commerce scalability of any physical Web server is limited, thus, by the number of user sessions it can maintain while still responding to each within a reasonable response time. With all the chores vying for CPU and other resources, some hefty, expensive servers can bog down while handling only a relatively small number of users.

Adding another server is an expensive proposition. Outfitted with fault-tolerant I/O, power supplies and so forth, along with one or more high-end processors, a ton of RAM and disk space, these e-commerce machines can soar into the five-figure cost range.

The strategy of the SmartNIC movement is deviously simple: Locate a network function consuming vast quantities of server resources and build a system that intercepts this traffic transparently and off-loads it to a processor resident on the NIC. Doing so unleashes new application processing capabilities in the newly unburdened server and, voila, the machine can handle three or four times the number of users. The legacy server remains doing the job and the expense of adding three or four more servers is spared. You can put a pretty high price tag on a NIC ($15,000) and still find a lot of people happy to pay for it.

3Com added a 3XP onboard processor to its EtherLink 10/100 PCI NIC some time ago. Its job is to handle some of the network tasks that otherwise would be pushed up to the server processor. Most significant, though, is its support for IPSecurity (IPSec) encryption/decryption functions. Tests of software-based IPSec encrypt/ decrypt illustrate the performance hit that the systems take. The 3Com offering handles it at the card level.

Intel takes a different approach, embedding a full-blown network processor as a PCI plug-in. Here, more intense applications such as firewalls can be processed at the hardware level.

Alacritech takes the server's TCP stack and implements it in hardware, which provides speedier TCP response and frees up server processing.

Akamba, goes even higher. It intercepts and handles the HTTP traffic that is part and parcel of every Web interaction - with dramatic effect as well.