It's musical chairs time at Silver Spring Networks.

Judy Lin, who had been serving as the chief product officer at the company, and John O'Farrell, who was executive vice president for business development, have both left the company. O'Farrell has joined Andreessen Horowitz, a venture capital firm. Lin is on vacation and couldn't be reached. The departures were amiable, according to Silver Spring.

Lin came to Silver Spring last year from Cisco, where she oversaw the Ethernet switching group. It was considered a coup because the rivalry between the two companies was just heating up. O'Farrell joined in early 2008.

Silver Spring -- which has raised over $275 million from investors -- has landed large, multimillion-dollar contracts with utilities in North America and elsewhere. It has also seen others in the industry come around to its way of thinking on a number of issues. The company was an early advocate of low-powered mesh networking for linking meters and open standards. Whether Silver Spring's networks is really open or a mix of open and proprietary standards has been an ongoing debate in the industry. Either way, other companies are now taking a similar approach, so hats off to SSN.

The rising profile, however, has also brought challenges. This week, Cisco inked an alliance with meter maker Itron and bought mesh networking specialist Arch Rock. Together, these two moves give the networking giant the elements of a platform upon which to compete directly against Silver Spring.

Sources also say that Silver Spring has been trying to enhance its strategy to pave the way for a long-anticipated initial public offering. A sizable portion of the revenue in these utility contracts ultimately ends up with meter makers. Silver Spring makes the radio card and provides services to its customer utilities, but the meters come from other manufacturers. (The SSN-powered meter on my house came from GE.) Networking technology can be a big business, but it doesn't encompass the entire contract; in other words, boosting margins could burnish the IPO. Many smart grid companies are putting an emphasis on the software applications that can reside on these networks.

Silver Spring has not commented on its strategy plans or the IPO, and our sourcing is anonymous. Thus, take that last paragraph with a grain of skepticism if you'd like. Nonetheless, this is what we are hearing.