The majority of businesses using VoIP today ,are using it internal to their company. This means they may have an IP PBX or equivalent solution installed on their premises and IP desktop phones or soft IP phones running on PCs for internal communication - yet connect to the public switched telephony network (PSTN) using analog or T1 circuits.
This connection is achieved through an IP to PSTN gateway device which can come in many forms (e.g. a stand alone solution or a card inserted into an IP PBX, PC or router). Some solutions also allow for communication directly to an Internet telephony service provider, typically using the SIP protocol. This allows for IP calls outside the business as well, typically at better call rates.
Cisco is just one of many equipment manufacturers that provide VoIP equipment and solutions. It is best to contact a few solutions providers and discuss with them your business challenges and ask them how their solution will meet your needs and ask them what components are involved to do so.
For example, a solution form Zultys Technologies can provide a number of functions in a small SIP based PBX that allows for direct connection to the PSTN or SIP service providers. This system can utilize your existing broadband connection or a separate broadband connection.
This was first published in October 2005