This allows the company and their customers to pay local rates internationally. Included in this is the ability for the company or it's customers to call a local number and have it routed through VoIP to the country where they also have an office and then hoping the call off of the internet onto the public network in that local country.
Some international companies are using VoIP to circumvent the high cost of international calling. Because if the network is wired properly (including possibly making use of fiber optic connectivity) the quality of sound far surpasses that of analog service. Some companies utilizing the technology by conducting all intra-office calls through a VoIP network. Whereas a standard PBX systems starts well above $5000, that same VoIP installation, with even more features, can be done in many cases for under $1000. The cost of a VoIP system compared to a standard PBX system is a fraction of the cost. Many larger companies have already switched to VoIP or have plans to do so. For large companies, VoIP also offers some very unique possibilities.