As a result of the evolution of wire-speed layer-3
switching from enterprise networks to the core of
public data networks, Packet Over SONET/SDH
(POS) has emerged as the technology of choice for
interconnecting high-speed backbone routers. POS is
deployed in the line cards of Gigabit and Terabit
routers and is implemented in hardware in order to
handle wire speeds ranging from 155 Mb/s to 10 Gb/s.