Nortel Networks Corp. (NYSE/Toronto: NT) has confirmed that its all-optical switch –- the Optera Px, derived from its $3.25 billion acquisition of Xros earlier this year -- is now in trials with an unidentified carrier.

This means that at least three vendors –- Corvis Corp. (Nasdaq: CORV), Lucent Technologies Inc. (NYSE: LU), and Nortel –- now claim to have all-optical switches in trials.

Lucent appears to be the furthest ahead in some respects. It shipped its Wavestar LambdaRouter to Global Crossing Ltd. (Nasdaq: GBLX) at the end of July, and it’s been carrying live traffic in trials on Global Crossing’s transatlantic cable since September 22.

At that time, Lucent issued a press release saying that the LambdaRouter would be carrying commercial traffic by the end of this year –- in other words, around about now (see Lucent Switch in Transatlantic Test). At press time, however, we weren’t able to confirm whether this is happening on schedule.

Corvis shipped its first all-optical switch to Broadwing Communications (NYSE: BRW) in October (see Corvis Delivers All-Optical Switch ). However, it’s tough to ascertain whether it’s still undergoing lab trials or whether it’s started carrying live traffic (see Corvis: Time to Come Clean?).

Corvis’s switch probably comes closer to being genuinely all-optical than Lucent’s, because it forms part of an all-optical package that includes transmission equipment and net management software. Lucent’s LambdaRouter switches light without converting it into electronics, but it isn’t integrated with a transmission system. As a result, light probably has to undergo a conversion when it comes out of the LambdaRouter. In practice, however, carriers may want this anyhow, to help them manage their networks (see Optical Illusions).

Right now, not much is known about the trials of Nortel’s Xros switch. The vendor is hoping to keep its powder dry for a possible press release when and if the carrier agrees to publicity.

Xros made a big splash earlier this year by claiming that its switch could scale to 1,024 by 1,024 ports –- but has yet to prove that it can conquer the challenges of making such a large-scale switch work in practice (see Xros's OFC Splash Was All Wet).

-- Peter Heywood, international editor, Light Reading http://www.lightreading.com