A method in one example comprises the steps of establishing a location
database for a first network that associates Internet Protocol address
information for VOIP telephony devices with physical locations for the
VOIP telephony devices; upon detecting registration of a VOIP telephony
device through a network port of the first network, determining physical
location of the VOIP telephony device by identifying physical location of
the network port through which the VOIP telephony device is connected,
and updating the location database; and, upon detecting IP telephony
activity originating from a remote VOIP telephony device connected to the
first network through a VPN gateway, determining physical location of the
remote VOIP telephony device connected through the VPN gateway by
identifying physical locations of network resources of a second network
to which the remote VOIP telephony device is connected, and updating the
location database; such that updated location information is provided to
a 911 server in the event that an emergency call is originated by any
VOIP telephony device or remote VOIP telephony device.