8:40 AM -- Just when things were looking relatively settled at Sonus Networks Inc. (Nasdaq: SONS), up pops a challenge to the VOIP technology's board from a major investor, with some sort of showdown likely at today's (June 20) annual shareholder meeting.

Legatum Capital, which claims to own 25 percent of Sonus's stock, this week fired off a very public missive, slamming the vendor for "years of poor operational performance" that has depressed the share price and resulted in "near five-year lows." (See Legatum Slams Sonus.)

The shares are currently worth $4.68. The five-year low came in early March this year, when the stock fell to $2.92.

About a year ago (early June 2007), though, the stock hit a four-year high, at $9.03.

As you would expect, Legatum's claims have not gone unanswered. Sonus chairman Hassan Ahmed has written, and distributed, a response ahead of today's meeting that tears into Legatum's claims. (See Sonus Responds to Legatum.)

Both documents are worth a read if you have an interest in Sonus.

The Sonus shareholders' meeting is being held in Westford, Mass., today, starting at 8:30 a.m. EST.

— Ray Le Maistre, International News Editor, Light Reading