AT&T continues to roll out Internet Protocol-based voice services through its U-verse network, announcing Monday the availability of the service in Sacramento, Calif. This is the fourth market for such a service, following launches in Michigan, Connecticut and Kansas.

The IP voice service fills out the company’s triple-play offering with cable TV, high-speed Internet, and now voice on one bill.

AT&T’s ‘Fiber-Rich Network’

AT&T said its U-verse voice service is a “managed IP-based service that is delivered over AT&T’s fiber-rich network, unlike many Voice over IP (VoIP) providers that offer best-effort digital phone services over the public Internet.” AT&T said its service provides better sound quality, reliability and calling features.

The advanced features that AT&T is highlighting include a single voice mailbox that can be reached from any phone or PC, and an online management portal so users can manage call preferences, contacts, call history and other preferences.

It also highlighted Call History, for viewing the most recent incoming or outgoing calls online, and Click to Call, which allows the user to dial any number in the Call History by clicking with a mouse or using the U-verse remote TV control. There is also an online Address Book, a Locate Me feature so an incoming call can ring on up to four wireless or landline numbers, and traditional calling features such as screening or blocking.

Focus on Price

Bruce McGregor, an analyst with industry research firm Current Analysis, noted that U-Verse voice was first announced in January, and the company is now rolling it out and adding more services.

He called it a “compelling” offer to customers compared to similar triple-play bundles from other phone and cable companies. AT&T has noted that it has features to differentiate itself from cable, including the AT&T U-bar, with customizable weather, news and traffic information; a YellowPages.com for searching;…