Subtending Multiple Systems
52 Avidia System Configuration and Management User Manual
Select Policing. The UPC policing function monitors and regulates traffic flow at the
interface to ensure the traffic conforms to the configured traffic contract (see page50 for
information about the traffic contract). Policing protects the network from intentional or
unintentional changes in the traffic contract that could affect other connections. If you
enable p olicing and traffic does not conform, it is deleted. Policing validates parameters
suchas VPI/VCI values, traffic rates conforming to contract. Policing can be enabled per one
ofthe following: ATM port, PVC, or PVP.
Subtending Configuration. When you subtend systems using DS1/DSX-1 cards, set up the
subtending relationships using the command-line interface.
Daisy Chain Management
A daisy chain is a serial link (or cascaded link) of up to three systems that has one network
uplink connection and is viewed as one integrated system. A daisy chain is an approach for
managing systems to support subscriberswho are physically separated by distance. The daisy
chain comprises:
•one system functioning on the edge of the network to aggregate and switch ATM
transmissions and provide the network uplink
•up to two systems functioning as accessdevices
Each system, whether subtending or subtended, can connect to and manage subscriber traffic
(modems).
“Daisy Chain Physical Implementation” on page52 shows how to set up the daisy chain using
Avidia systems. “Daisy Chain Configuration” on page55 , shows how to configure the system
to implement the appropriate connections.

Daisy Chain Physical Implementation

The relationship of subtending in a daisy chain configuration is shown in the following figure.
Use two cards per system to connect a daisy chain. One card, used as a line-side interface,
connects to the next system upstream in the chain. Upstream connects toward the network
interface. The second card, used as a channel-side interface, connects to the next system
downstream in the chain. Downstream connects further from the network interface.
Theexample shows an OC3 interface as the network uplink for the entire subtended system. An
AV8000 or AV3000 is the subtending system. The two chassis are subtended and are at two
separate physical locations (sites). The subtending connection is through a DS3 link.