A CMTS provides an extended Ethernet
network over a WAN with a geographic reach up to 100 miles. The
cable data network may be fully managed by the local cable
operations unit or operations may be aggregated at a regional NOC
for better scaling. A given geographic or metropolitan region may
have a few cable television headend locations that are connected by
fiber links. The day-to-day operations and management of a cable
data network may be consolidated at a single location, such as a
regional center, while other headend locations may be economically
managed as local centers.
A basic distribution center is a
minimal data network configuration that exists within a cable
television headend. A typical headend is equipped with satellite
receivers, fiber connections to other regional headend locations,
and upstream RF receivers for pay-per-view and data services.
The minimal data network configuration includes a CMTS system
capable of upstream and downstream data transport and an IP router
to connect to the regional location.
A regional center is a cable headend
location with additional temperature-controlled facilities to house
a variety of computer servers, which are necessary to run cable data
networks. The servers include file transfer, user authorization and
accounting, log control (syslog), IP address assignment and
administration (Dynamic Host Configuration Protocol [DHCP] servers),
Domain Name System (DNS) servers, and Data-over-Cable Service
Interface Specification (DOCSIS) control servers. In addition, a
regional center may contain support and network management systems
necessary for the television as well as data network operations.
User data from local and regional
locations is received at a regional data center for further
aggregation and distribution throughout the network.
A regional data center supports DHCP, DNS, and log control servers
necessary for the cable data network administration. A regional data
center provides connectivity to the Internet and the World Wide Web
and contains the server farms necessary to support Internet
services. These servers include e-mail, Web hosting, news, chat,
proxy, caching, and streaming-media servers.