Although we don't believe in timing the market or panicking over market movements, we do like to keep an eye on big changes -- just in case they're material to our investing thesis.

What: Shares of voice and data networking gear maker Sonus Networks (NYSE: SONS) came back like a prodigal son today, jumping as much as 19.7% on extraordinary volume.

So what: Sonus just reported third-quarter results with $0.01 of earnings per share on $66.4 million in sales -- ahead of analysts on the top line and exactly as expected on the bottom line. Shares are now back where they were at the start of 2011 and again three months ago.

Now what: The company competes with Acme Packet (Nasdaq: APKT) and BroadSoft (Nasdaq: BSFT) in the market for scalable subscriber-based network equipment -- and is doing a fine job of it at the moment. Some of the delayed orders from last quarter's revenue miss showed up as sales in this period, proving once again that lumpy results can be strong in the long run. This stock looked so cheap that I bought shares about a year ago -- and it's just as affordable today. I'm looking for Sonus to produce stronger cash flows, but otherwise I'm quite content with these results.

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Fool contributor Anders Bylund owns shares of Sonus Networks but holds no other position in any of the companies mentioned. Motley Fool newsletter services have recommended buying shares of Acme Packet. Try any of our Foolish newsletter services free for 30 days. We Fools may not all hold the same opinion, but we all believe that considering a diverse range of insights makes us better investors. Check out Anders' holdings and bio, or follow him on Twitter and Google+. We have a disclosure policy.