Collecting customers is one thing. Now Ciena (CIEN) - Get Report investors are getting antsy about when the cash will start tumbling in.

After

posting slightly weaker-than-expected third-quarter sales and warning of a possible fourth-quarter slide, the networking gearmaker on Thursday had its fans pondering once more when Ciena might fulfill its considerable promise.

The question arises because Ciena remains the rare telecom shop hoping to pursue success through growth. Where many rivals have jettisoned promising but unprofitable businesses, Ciena has been acquiring. And having compiled an impressive list of telco customers over the past year --

AT&T

(T) - Get Report

,

Telmex

(TMX)

and

British Telecom

(BTY)

come to mind -- Ciena has "potential" written all over it.

But Thursday wasn't the day for realizing Wall Street's dreams, as a glaring absence of big orders fed Ciena's second-straight quarterly sales decline. After sliding 7% early, the stock was unchanged around midday at $5.82.

"We're not where we want to be," said CEO Gary Smith in an interview after the earnings call. He added that the company is working on "translating wins into revenues."

And that's exactly what concerns the investment crowd that once fancied Ciena as a strong upstart poised for breakaway sales success at the expense of larger rivals

Cisco

(CSCO) - Get Report

,

Lucent

(LU)

and

Nortel

(NT)

.

Instead, Ciena is now facing a three-quarter top-line losing streak.

Smith says the buying process is a fickle one, a chain of events that's determined entirely by the whims of major customers. In part, it's a matter of timing, says Smith. The orders will come, he says, but they are subject to the "lumpiness of large carriers."

But while Smith predicts orders are being lumped, others predict they are being dumped.

"I like Ciena. I don't think it's necessarily their fault," says Telecom Pragmatics' analyst Sam Greenholtz, referring to the shifting fortunes of telco customers and competing products edging into Ciena's turf. That said, "I think they believe these revenues are coming, but there are a lot of other things going on."

For example, analysts blame tight-fisted Telmex for much of the sales shortfall, and note that AT&T has been mostly quiet on the order front. Others wonder if Ciena's highly regarded optical switch, the CoreDirector, is suffering through a slowdown in demand as big network expansion plans get pushed aside.

Observers credit Ciena for its bold acquire-through-the-gloom strategy that helps take the focus off its core optical business by highlighting new products and customers added to the mix.

To be sure, the company's in no danger of facing financial problems. Though it continues to lose money, the company has a hefty bank balance, with $1.75 billion in cash and investments. That has allowed Ciena to buy some proven technologies, a strategy that Smith emphasizes isn't a smokescreen to hide any weakness in its main business.

"We've been very clear about getting into additional markets. We've been consistent about it from the start," says Smith. "Time will tell if we are right or not."

And though Ciena gave investors little to cheer about in the near term, some on Wall Street say there's eventually going to be a big-bang quarter when some of these orders come through.

"Ciena is in a better position now than they were when they traded for $100 a few years ago," says one New York hedge fund manager who is long the stock. "Back then they only had optical. Now, they have optical along with

network access and data equipment."

Yes, time will tell.