Trouble on the horizon for networking companies? Or, is it already here?

Alcatel-Lucent (NYSE: ALU) stock has taken a beating today (it was down 15 percent in Paris and more than 16 percent on the NYSE as of this morning) after it reported second-quarter earnings that left analysts more than a little concerned, despite the fact that the networking company is looking at what could be its first profitable year since the 2006 merger that threw together French company Alcatel with American company Lucent.

Competitor Juniper Networks (NYSE: JNPR), meanwhile, continued its decline today after its earnings report Tuesday sent its shares down 21 percent, more than a fifth of its value, or close to $3.3 billion of its market cap, during trading Wednesday. The oft-mentioned Cisco (NASDAQ: CSCO) competitor has seen its share price decrease 33 percent this year.

This week's tumble was caused by sales and profits that missed estimates and was exacerbated by guidance that said the bleeding isn't done yet. The company said slower-than-expected spending by some customers, including Internet carriers, and concerns about the economy could slow things down even more in the second half of the year... which sent analysts scurrying to downgrade the stock (at least 10 did).

As Piper Jaffrey analyst Troy Jensen said, "The magnitude of negative data points was surprising. We believe Juniper could likely hit a several-quarter air pocket."

He was among the analysts cutting his outlook on the company, lowering his target from $47 to $30.

The bigger question now facing networking companies is, "Just how bad will things get?"

AT&T and Verizon Wireless are expected to spend less on network improvements in the second half than they did in the first, the reverse of what has become almost de rigueur.

"This is a change to historical patterns, [and] we see similar trends with the top 15 service providers globally," Juniper Chief Executive Kevin Johnson said on the company's conference call.

Cisco's well-publicized woes, which prompted CEO John Chambers in May to vow to cut $1 billion in operation costs, by shedding under-performing products and divisions and making cuts to its workforce, could be attributed to slowed growth throughout the segment rather than Cisco's assumed "lack of focus on its core business."

But we'll find out more about that when the company (which is up some 3 percent today) rolls out its financial results Aug. 10.

With the continued growth in the demand for videoconferecing and high-end teleconferencing, and the chunks of data they produce, you'd think networking equipment would be flying out the door. But, as Avian Securities analyst Catharine Trebnick told Bloomberg, there may be more at work that miscalculations by Cisco et al.

"It's a looking glass into Cisco and it's a reflection of what is happening in Cisco," she said. "It highlights that the enterprises are in a phase of deliberate spending."--Jim