Now's the Time to Warm Up to Web Switches.
Data Communications, August 7, 1999 p17
Author
Lippis, Nick
Summary
Competition among competitive local exchange carriers (CLEC) is making WAN bandwidth cheaper, and
web servers are increasing in value as more businesses rely on them. The convergence of these trends
makes web switches more valuable components of enterprise networks. Web server farms are often an
amalgam of Intel-based PCs, each performing a specific network function, but second-generation web
sites need more efficient server architectures to provide the performance electronic commerce
applications require. Web switches will likely evolve much as routers evolved: from single-function
devices to integrated distributed processors with higher performance and easier management. Allaire,
IBM and Resonate are among the vendors offering software-only solutions for connecting web server
farms to the Internet, but they do not scale to large enterprises. Cabletron Systems, Cisco Systems,
Extreme Networks, Nortel Networks and other Layer 3 switch vendors will likely implement web
switching in their products. Leading web switch vendors are Alteon Websystems, Arrowpoint
Communications and Foundry Networks, with Alteon's 700 web switch a standout.
Full Text
Let's start with something simple. The Internet isn't going to stop growing anytime soon; it represents a
fundamental economic shift for the U.S. and countries around the world. So what does that mean to
network architects? The 'Net needs a special piece of equipment: I call it a Web switch. And now's the
time to get familiar with its functions. Consider a couple other trends. WAN bandwidth is getting cheaper
and cheaper, thanks to the more than 1,000 CLECs (competitive local-exchange carriers) now competing
for new customers. What's more, the value of Web servers is skyrocketing as they become essential
business drivers. Now lets add one and one together: If the price of bandwidth is going through the floor
and the importance of Web servers is going through the ceiling, Internet traffic-and Web
transactions-have only one place to go: up. Savvy network planners will start reviewing where particular
Web tasks are performed, making sure their company's business is free to scale. If they concentrate on
the space between WAN routing and Web servers, they'll be able to see where Web switches will prove
their value.
E-Everything
Before I divulge the details of Web switching, let's take a look at what's spurring this market on.
E-commerce concerns such as amazon.com, e-bay, e-toys, e-trade, Ticketmaster Online, and the rest
are too hot to handle. The rest of the world can't wait to get into some sort of virtual business.
Have you ever seen the typical Web server farm? It makes the bedroom of a 14-year-old hacker look tidy
by comparison. Before a packet can even reach a server, it has to traverse a router, bandwidth manager,
global load balancer, firewall and VPN server, local load balancer, and Layer 2/3 switch-which finally
passes it along to a cluster of Web servers, application servers, data servers, and backup storage.
That's a lot of devices along the way, and these days most of them are standalone. So for virtually every
one of these network tasks, there is an Intel-based PC performing the function. This approach may have
been fine for first-generation Web sites, but second-generation sites must lower the interference and
eliminate these separate management points.
How can I be so sure? Let's look at performance. If a Web server farm is connected to the Internet via T3
(45 Mbit/s), it could be called upon to service some 16,700 sessions per second. Most standalone
devices will choke on the load. In fact, as the number of connection requests per second increases, the
total number of successfully established sessions actually falls because they're being handled by a
single-processor architecture. That's why I expect Web switches to repeat the evolution of routers:
Single-function devices will give way to integrated distributed processing. Performance will climb while
management will become less complex, reducing associated risks.
Memory Lane
Remember, routers started out running on Unix servers. It wasn't too long before everyone figured out
that this approach wouldn't scale and that servers should be focused on applications rather than
counting packets. As routers grew more sophisticated, software upgrades and hardier hardware boosted
their abilities and ultimately separated forwarding from route calculation.
We already have several schemes for connecting Web server farms to the Internet. The first is a
software-only solution that handles most of the tasks mentioned above, from vendors like Allaire Corp.
(Cambridge, Mass.), IBM, and Resonate Inc. (Mountain View, Calif.). While their products may be fine for
small sites with one or two Web servers, they clearly will not scale to the needs of large enterprises. Then
there are the IP appliances-bandwidth managers, load balancers, firewalls, and VPN terminators. This is
a very fragmented market, and there's no single way to manage all these devices, which both increases
complexity and adds risk.
I also expect all the established Layer 3 switch vendors to implement these tasks on their products:
Cabletron Systems Inc. (Rochester, N.H.), Cisco Systems Inc. (San Jose, Calif.), Extreme Networks Inc.
(Santa Clara, Calif.), and Nortel Networks Corp. (Brampton, Ontario). They're going to take the
management module approach, and I happen to believe their performance will not be any better than
that of IP appliances.
Web Switch Roundup
Finally, there are the Web switch companies: Alteon Websystems Inc. (San Jose, Calif.), Arrowpoint
Communications Inc. (Westford, Mass.), and Foundry Networks Inc. (Sunnyvale, Calif.).
So what exactly are these wonder-workers? Web switches are single high-performance devices that
handle all the network tasks I discussed above. They're server-aware, ensuring optimum load
distribution across farms, noting availability and helping with performance management. They're
application-aware, providing state management for Web sessions and apps alike-be they TCP, UDP
(user datagram protocol), SSL (secure sockets layer), or even shopping-cart transactions. They're
content-aware, parsing sessions and providing efficient and granular load distribution. And they're
network-aware, supporting key routing protocols and WAN and LAN interfaces.
Of all the companies in this space, Alteon Websystems is the standout.
It has built all the requisite network-ing tasks into its 700 Web switch from the ground up, rather than
placing them on a management module with questionable scalability. The 700 exploits ASICs
(application-specific integrated circuits) to cast into silicon repetitive networking tasks like address
filtering; session mapping and forwarding; TCP, UDP, and IP state tracking; load balancing; bandwidth
management; and much, much more. These ASICs are riding on every module and linked via a
high-speed switching fabric that can keep pace with the e-business of Web sites such as Exodus, Yahoo,
and Uunet's hosting service.
These days, everyone out there is eager to get in on the next big Internet thing, hoping to make a killing
on an IPO. Network architects looking for a really big deal should start checking out Web switches. You
may not get rich, but your company certainly stands to profit. Good hunting. |
