A Media Gateway converts data from the format used in one network to the format used in another. Media Gateways act as entry points to other networks. In a typical setup, the gateway will be associated with a router and a switch. The router will know where to route a particular packet of data that arrives at the gateway, whilst the switch will set up the path in and out of the gateway for particular packets of data. Many Nexbridge customers who do not have a SIP capable PBX use a SIP media gateway to interconnect.