The company had previously indicated that 2013 revenues would be 10 to 20 percent higher than 2012's. In delivering first-quarter results Wednesday afternoon, Infinera CTO Ita Brennan said she's "comfortable with the upper range" of that forecast.

It was a pretty safe statement, given that Infinera's first-quarter revenues were 19 percent higher than a year earlier. Infinera also predicted second-quarter revenues of $130 million to $140 million; analysts had been expecting more like $124 million, according to Thomson Reuters.

Infinera shares were up 79 cents (12%) at $7.45 in after-hours trading.

Infinera's year is riding on the fortunes of the DTN-X long-haul DWDM system, which so far is doing well as the 100Gbit/s generation emerges for optical transport. The system has 27 customers, Infinera CEO Tom Fallon said on Wednesday's conference call with analysts. That's up from 24 as of OFC/NFOEC a little more than a month ago.

"The DTN-X rollout is hitting on all cylinders," analyst Mike Genovese of MKM Partners wrote in a research note late last week.

As sunny as all that sounds, Infinera is still losing money. Its gross margins will remain relatively low while the DTN-X is still in initial rollouts with customers, because the chassis itself carries lower margins than the line cards that eventually fill it.

Infinera's gross margins for the first quarter were 36 percent. The last time Infinera's revenues got up to about $130 million -- which was the third quarter of 2010 -- its gross margins were 51 percent, as Juda Group analyst Natarajan "Subu" Subrahmanyan alluded to at one point on the earnings call.

For its first quarter, which ended March 30, Infinera reported revenues of $124.6 million and net losses of $15.3 million, or 13 cents per share.

For the same quarter a year ago, Infinera had reported revenues of $104.7 million and net losses of $20.6 million, or 19 cents per share.

Non-GAAP losses (after one-time costs) of 6 cents per share were slightly better than the analysts' consensus expectation of 7 cents, according to Thomson Reuters.

For more

• 100G Land Grab Is Well Underway
• Infinera Officially Lands CenturyLink
• Infinera Slices & Dices Its 500G

— Craig Matsumoto, Managing Editor, Light Reading