An IP phone that runs the session border controller (SBC), which encrypts traffic, reconnects calls if dropped, overcomes firewall issues and routes internal calls within the network. Without an SBC within at least one phone in the network, a call from one phone extension to another employee in the next room traverses the Internet to a datacenter and back again. If no router phones are used, an SBC can generally be installed in a computer in the network. See
session border controller and
IP phone.