1/7/2008 -- Don't look now, but sales are booming in the WAN optimization appliance segment, where sales went up 20 percent in the third quarter of last year, while unit shipments surged by 16 percent.

And the enterprise routing segment, in spite of its shaky start, appears to have rebounded very nicely, thank you.

That's encouraging growth by any measure, says market watcher Infonetics Research. Nor is that all, according to Infonetics: From the third quarter of 2006 through the same period last year, quarterly manufacturer revenue for WAN optimization appliances nearly doubled. The upshot, the market watcher projects, is that WAN optimization appliance sales should continue to post strong growth.

"The WAN optimization market continues to do well; we expect another sequential gain in the fourth quarter, ending the year on an up note, and 65 percent year-over-year annual growth," said Infonetics Research directing analyst Matthias Machowinski in a statement.

Ditto for the enterprise router market, which got off to a shaky start during the first part of 2007.

"In the enterprise router market, we saw some weakness in the beginning of 2007, but the market has steadily improved over the year, and we expect it to finish strong with a solid fourth quarter due to pent-up demand," Machowinski said.

Overall, unit shipments of WAN optimization appliances are predicted to quadruple between 2006 and 2010, according to Infonetics. Enterprise router sales, on the other hand, were up 4 percent sequentially in Q3 of 2007, with gains in all segments of the market -- including the high-end, mid-range, branch and low-end/SOHO segments. For the quarter, Infonetics says, mid-range routers make up 39 percent of the total enterprise router revenue pie.

So who are the market leaders? In the WAN optimization segment, Riverbed maintains its lead on Cisco Systems Inc. (the No. 2 player) and Blue Coat, which moved into third place. Not surprisingly, Cisco remains the enterprise routing market leader, followed by Juniper and Huawei for revenue share. --Stephen Swoyer