Cisco Systems (Nasdaq: CSCO) executive John McCool, a senior vice president who led sales of corporate mobile and networking gear, is departing and will be replaced by Tom Wilburn.

A 17-year veteran of Cisco, McCool is leaving his position as chief technology officer of the global enterprise segment, San Jose, California-based Cisco said today in an e-mailed statement. Wilburn, who has been at Cisco eight years, has experience in mobility, switching and routing, the company said.

Wilburn takes charge of a unit responsible for a third of revenue as Chief Executive Officer John Chambers works to fend of competition from software startups selling networking technology. McCool may end up leading one of Cisco’s software rivals, according to Brent Bracelin, an analyst at Pacific Crest Securities.

“Given all the innovation happening in networking these days, I’m sure there’s lots of opportunity for a person like John,” Bracelin said. “We’re seeing more departures like this from big incumbent technology companies.”

Cisco operates its second largest corporate campus in RTP with some 5,000yees.

Other Exits

McCool’s exit adds to a list of top managers who have left Cisco in recent years. Paul Mountford, a senior vice president who ran the network-equipment maker’s global sales to businesses, exited in August amid a restructuring aimed at reducing market-share losses and cutting costs.

Ned Hooper, who ran mergers and acquisitions, resigned in June, a year after his second-in-command, Charles Carmel, left. Former Senior Vice President Tony Bates left to run Skype Technologies SA in 2010.

McCool didn’t immediately respond to requests for comment. David McCulloch, a Cisco spokesman, declined to comment on why McCool left or where he would go next.

Cisco promoted Scott Lovett to head of sales for security products, previously part of McCool’s duties, McCulloch said.

A long-time engineering manager, McCool designed networking gear for Steve Jobs’s NeXT Computer in the early 1990s, before joining Cisco in 1996 via its acquisition of Granite Systems, according to Cisco’s website.

McCool helped grow Cisco’s Catalyst line of switches into a multi-billion dollar business, and oversaw development and sales of gear designed specifically for large data centers from 2008 to 2011. That business grew from $5 million to more than $1 billion on his watch, Cisco said.

Cisco’s shares rose 1.9 percent to $20.97 at the close in New York, for the biggest gain in five weeks. The stock has advanced 6.7 percent this year, compared with a 10 percent gain for the Standard & Poor’s 500 Index.