As Google prepares to provide one of its first telecom-related Web services, courtesy of recent acquisition Grand Central, the search giant stumbled out of the box.

Google admitted this week it was forced to provide several hundred users of Grand Central’s call-routing service with a new phone number. That ran counter to the service’s calling card: offering users “one number for life” that would cover all of their phones and locations.

Google ran into its problem when it began to work with carriers as it transitioned the acquired service. At least one unnamed carrier said it would not be able to support the numbers they had previously assigned to GrandCentral users, forcing Google to scramble to obtain and give those users new numbers. The new numbers are slated to become operational at the end of this month.

Grand Central offers an innovative--and so-far free--service that lets users hand out a single phone number and use a Web-based interface to route calls to that number through to any of their wired or wireless phones.

Routing to multiple devices was part of the appeal; but being able to obtain and use a single number “for life,” regardless of whether one changed carriers, moved across country or bought new phones was also a major selling point.