ATM OC-3c/STM-1c Intermediate Reach Card
Traffic Card Descriptions
2-5
ATM OC-3c/STM-1c Intermediate Reach Card
The ATM OC-3c/STM-1c Intermediate Reach (IR) card supports four SONET or SDH SMF ports, each of
which operates at 155 Mbps, and can be used either as optical line or optical trunk interfaces. Figure 2-2
shows the front panel of the ATM OC-3c/STM-1c IR card. A low-density version provides two ports that
are enabled through software entitlement.
The card uses two SAR devices, which perform the reassembly function on the incoming ATM cell stream
from the PHY device and the segmentation function to create the corresponding outgoing ATM cell stream.
The hardware provides HEC framing for each port; the transmit clock can be derived either from the active
controller card or from the onboard local oscillator.
The second-generation ATM OC-3c/STM-1c card has increased memory for each port and offers higher
performance and support for more ATM virtual paths (VPs) and PVCs than an earlier version of the card.
The SAR devices support two, four, or eight distinct class of service queues for each ATM PVC, allowing
a mix of priority- and class-based queuing for each ATM PVC.
For information about ATM VPs and PVC support, see the
Ports, Circuits, and Tunnels Configuration
Guide
for the SmartEdge OS. A low-density version of this card provides two ports that are enabled
through software entitlement.
Figure 2-2
ATM OC-3c/STM-1c IR Card
Note
The 4-port version is referred to as a second-generation ATM OC-3 card.
