Network choices have changed considerably since the days when private leased lines were the predominant option for business connectivity. The availability of MPLS services and Internet-based VPNs has enabled enterprises to acquire greater bandwidth at lower prices - but not without making sacrifices, says Silver Peak Systems' CEO Rick Tinsley.

There’s a trend in enterprise networking toward higher bandwidth, but a lot of the technologies that enable carriers to provide more bandwidth for less money every year have a tradeoff that’s not been very well documented and is only beginning to be understood. It’s the tradeoff of quality vs. quantity,” Tinsley says.

I caught up with Tinsley recently to discuss some trends in the WAN optimization market, including the hidden costs of cheaper WAN bandwidth.

More than 67% of global enterprises have begun deployment of MPLS, Tinsley says, citing Forrester Research data. In addition, 76% of enterprises anticipate using Internet VPNs in the next five years, according to Silver Peak data.

Both these network options have packet loss and produce out-of-order packets. That’s not news to most people. But what is just beginning to be understood is the impact of packet delivery issues on application performance.

Enterprises that have deployed VoIP applications understand the significance of dropped packets on call quality, for example, but voice isn’t the only packet-sensitive application, Tinsley says. Virtual desktops are becoming a popular option
for enterprises that have centralized corporate applications, and early adopters are finding many virtualized applications are extremely sensitive to packet loss, Tinsley says.

“I wouldn’t call it a train wreck, but it is going to be a very significant challenge for large enterprises,” he says. “They’re moving to these lower connectivity network options, just at the same time that they need the network to support things like voice and video and desktop virtualization apps. That’s going to be a problem -- the networking trends versus the application trends.”

After experiencing much success deploying server virtualization technology in the data center -- which works very well and works predictably for most applications -- enterprises are going to be surprised when they virtualize their desktops and find it’s not so smooth, he says.

“Essentially, for those desktops that have plenty of bandwidth and high quality connectivity to the data center, desktop virtualization is going to be a pretty positive experience. But for those desktops that are, let’s say, far away and maybe don’t have good quality connectivity to the data center, users are going to scream bloody murder when their applications get virtualized because their performance is just going to go down the tubes.”

“Much like the trials and tribulations that enterprises have had with rolling out VoIP on an enterprise basis, they’re going to run into some of the same problems -- and perhaps even more difficult problems -- when they attempt to virtualize desktops,” Tinsley says.

We also talked about the economy, and sales of Silver Peak’s WAN optimization appliances.

Silver Peak’s family of appliances ranges from the NX-2000 line, launched in March, to the high-end NX-9000, launched in May. The NX-2000 appliances support up to 2 Mbps of WAN traffic and are geared for small branch and remote offices. The NX-9000 supports up to 4Gbps of bidirectional LAN side traffic and 1Gbps of bidirectional WAN side traffic and is designed to accelerate high-volume traffic (for SAN replication and remote office backups, for example) flowing between data centers, as well as traffic between data centers and remote corporate sites.

"I see a lot of softening in the market,” Tinsley says. “I think in this kind of time, you better be focused on opportunities that have a very clear, distinct and tangible ROI. For instance, if we’re enabling a customer to move from a very expensive private line network to a lower-cost MPLS or Internet-based network, so they’re going to dramatically lower their cost of bandwidth but maintain the same or even better quality by using WAN acceleration techniques, that project is going to get funded because it’s a clear ROI.”

“If on the other hand, let’s say you’re just focused on accelerating e-mail or a few end user applications, the cost savings or the productivity savings for the customer may be difficult to quantify,” he says. “These are the types of times when CFOs don’t sign off on productivity enhancements. Those are the types of purchases that are at risk when times get tough like this.”

Ann Bednarz is associate news editor at Network World.