4:30 PM -- An old favorite among rumors, the one about Ericsson AB (Nasdaq: ERIC) buying Juniper Networks Inc. (NYSE: JNPR), popped up again recently in whispers. As of last night, Juniper's stock was up 32 percent since Aug. 1 (to $17.52 last night, from $13.29), and maybe, the theory goes, renewed acquisition talks are the reason.

Analysts get a good laugh when I ask about this. (See Analysts Dismiss Ericsson/Juniper Talk.) Really, I could call up on any random day, tell them there's a "rumor" about Ericsson/Juniper, and I'd be right, and they wouldn't care.

(Hey, at least it's not the one about Extreme Networks Inc. (Nasdaq: EXTR) -- see Juniper's Extreme Thoughts Are Back.)

Well, OK, what's with the runup, then? Tim Daubenspeck of Pacific Crest Securities Inc. thinks it's more likely investors are confident Juniper will make its quarter. He also thinks they're getting happier with Juniper's story, particularly as the company rolls out more pieces of Ethernet -- the latest being this morning's MX960 announcement. (See Juniper Antes Up on Ethernet (Finally).)

Something else to consider: Cisco Systems Inc. (Nasdaq: CSCO) is up 40 percent since Aug. 1, so Juniper's recent run isn't all that anomalous.

So, it's a happy time for Juniper. The next step is to see if it stays that way after today's earnings call.

— Craig Matsumoto, Senior Editor, Light Reading