ABSTRACT
Many advanced routers will be set up in Central Office (CO) locations. The reason for this is that routers will replace many Public Switched Telephony Network (PSTN) Class 4 CO switches. Bandwidth in the core network will become more important to carriers. The shift of paradigm towards an IP backbone has already taken place. While the Class 5 CO switch will remain in place for a while, the backbone will be entirely IPv6-based, and as a result, the routers in CO applications will have to take over functions of the Class 4 switch. Consequently, the carriers will make sure that routers replacing the Class 4 switches will fulfill the same environmental and space requirements.
