4:05 PM -- Being an AT&T Inc. (NYSE: T) domain supplier has its privileges. And not being one -- well...

Tellabs Inc. (Nasdaq: TLAB; Frankfurt: BTLA) stock is down 10 percent today and has "significantly underperformed" all week "on concerns its competitive position at AT&T is weakening due to lack of domain vendor status and the carrier's planned transition to LTE/4G," analyst Michael Genovese of Soleil writes in a report issued today.

AT&T makes up about 20 percent of Tellabs's revenues, with wireless backhaul being a good chunk of that, Genovese notes. As AT&T starts building for LTE, that backhaul business could be destined for Alcatel-Lucent (NYSE: ALU), he writes.

AlcaLu already has a pretty good position at AT&T. It's a domain supplier for routers and for LTE radio access, a combination that's led to more pre-LTE backhaul business for the vendor, Genovese writes. (See AT&T Picks AlcaLu, Ericsson for LTE.)

— Craig Matsumoto, West Coast Editor, Light Reading