A licensing firm has filed suit against AT&T and Apple, alleging the iPhone's “Visual Voicemail” system infringes two of its patents. Klausner Technologies says it owns two patents on a “telephone answering device linking displayed data with recorded audio message.”

The suit, filed Dec. 3 in federal district court in Texas, seeks an estimated total of $360 million in damages and future royalties from AT&T and Apple, which respectively sell and designed the iPhone.

Both the iPhone system and the Klausner-patented system allow users to view of list of messages. Included with the list are the callers' phone numbers and any information stored in the phone that is linked to those numbers, such as names and contact information. The user can choose from the list to listen to the messages selectively.

According to a Klausner press release, Apple has hyped the iPhone's Visual Voicemail system as “one of the greatest advances in the history of mankind … without question.”

Klausner has licensed one of those patents to Vonage and Sprint after settling similar suits. AOL also licenses the technology. According to Web site Ars Technica, Klausner has also filed suits against Comcast, Cablevision and eBay for infringement of the same patent.

“We have litigated this patent successfully on two prior occasions,” said Greg Dovel, counsel for Klausner Technologies, in the release. “With the signing of each new licensee, we continue to receive further confirmation of the strength of our visual voicemail patents.”