IP Telephony?

How can IP telephony help mobile workers to be more productive?

Mobile users want the convenience of all of the communications tools they use at the office when they are not at their desk. They want an intuitive way to communicate easily on the device of their choice, anywhere they work, and stay connected through one phone number and one message mailbox. Before the convergence of IP telephony and wireless communications this concept was a pipe dream. The expense of enterprise enabling workers made it impractical to extend communication features beyond a wireline radius of the PBX and impossible to extend them across the PSTN.