A calling and called telecommunications station are each connected to a
packet access network. The packet access network under the control of a
server system, determines whether an originating call should be routed via
a core packet network, such as the Internet, or a Public Switched
Telephone Network (PSTN). If the expected delay of packets through the
core packet network is excessive, then the call will be connected through
the Public Switched Telephone Network. If, during the course of a call,
the packet delay becomes excessive, and causes the quality of voice
transmission to be below acceptable standards, the call is switched from
the packet network to the Public Switched Telephone Network.
Advantageously, as many calls as can be handled by the packet network are
switched through that network, thus resulting in substantial savings to
the customer. Advantageously, the embedded PSTN can be used productively
to handle overflows from the core packet network. Advantageously, the
quality of voice calls through the core packet network can be maintained
by re-routing existing calls through the PSTN when necessary.
