3021M100-002
19-1
19
ATM I/O CAR
The ATM I/O card enables the CX950 to have WAN access to an ATM network at
T1/E1 speeds. A maximum of two cards can be installed on the motherboard in
slots 1-4.
The card performs the following basic functions when transmitting data to th
network:
• accepts packetized data from the motherboard via the PCI interface
• performs hardware segmentation of the data into ATM cells
• adds the appropriate physical layer to the cells
• transmits the cells on to the network.
The ATM I/O card also performs these functions in reverse when data is received
from the network, thus providing full duplex operation.
19.1 ATM I/O Card Components
This section describes the major components of the ATM I/O card. The physical
layout of the components is shown in Figure 19-1. Figure 19-2 provides a
functional block diagram of the card.