Although we don't believe in timing the market or panicking over market movements, we do like to keep an eye on big changes -- just in case they're material to our investing thesis.

What: Shares of high-speed networking equipment builder Juniper Networks (NYSE:JNPR) jumped as much as 15% higher in early Friday trading  and by 2:50 p.m. had settled to a 4% increase. The company reported strong second-quarter earnings on Thursday night, topped with optimistic guidance for the third quarter.

So what: In the second quarter, Juniper saw sales decline 1% year-over-year to land at $1.22 billion. Analysts were looking for just $1.11 billion, or a 10% drop. On the bottom line, adjusted earnings rose 33% to $0.53 per share while the Street would have settled for flat growth at $0.40 per share.

Looking ahead, Juniper expects third-quarter earnings of roughly $0.52 per share on revenues near $1.23 billion. Here, analyst consensus currently points at earnings of $0.46 per share on $1.16 billion in sales.

Now what: Juniper is on a long-term roll. The company has exceeded earnings estimates in 12 of the last 13 quarters, simply meeting expectations in the 13th period. It's an impressive streak, starting all the way back in the summer of 2012. Juniper didn't shake up its management, revamp its business strategy, or make any other huge changes to the company in 2012, but the company got its operating act together at that point anyhow.

JNPR Chart

JNPR data by YCharts

Snapping back to the present day, Juniper CEO Rami Rahim said that Juniper's second-quarter results rested on a strong product portfolio and sharp execution.

"Overall, this quarter is a good proof point that Juniper's strategy is winning and the investments we have made are producing positive results," Rahim said in a press statement. "Our results reflect the diversity of our customer base and we believe this positions us well to capitalize on the market opportunity throughout 2015 and beyond."

On the earnings call, Rahim underscored Juniper's long-term focus in the face of difficult market conditions. "We remain steadfast in our commitment to drive profitable long-term growth and increase shareholder value," he said.

If nothing else, Juniper's leadership has done an excellent job of calming investor nerves in recent years. Sales and cash flows hit a peak last summer, then started falling over the next several quarters. Yet, share prices have climbed 18% higher in 52 weeks as investors accepted Juniper as a long-term investment.

Anders Bylund has no position in any stocks mentioned. The Motley Fool has no position in any of the stocks mentioned. Try any of our Foolish newsletter services free for 30 days. We Fools may not all hold the same opinions, but we all believe that considering a diverse range of insights makes us better investors. The Motley Fool has a disclosure policy.