Filter
Top Products
Cabling and Configuring the 25 Mbps Port Adaptor Modules 9-3
Overview of the 25-Mbps Port Adapter Module
25 Mbps PAM Features
The 25 Mbps PAMs provide the following features:
• Support for 12 ATM UNI ports at standard throughput rate of 25.6 Mbps full duplex.
• Compatible with ATM Forum 25.6 Mbps PHY specification for UTP-3, UTP-5, or
STP-5 except that the RJ-45 connector is replaced with a Molex 96-pin female
connector. (A cable assembly with 12 RJ-45 standard connectors is provided with the
PAM.)
• A CPU bus interface for control and monitoring of the board ID EEPROM and LEDs.
• Priority queueing (4 levels) at each transmit (TX) output port.
• Buffer memory for transmitand receive (RX) cellsand for eachgroup of six ports;128K
by 16-bit local external SRAM for flexible queueing of 4,092 cells in transmit data path.
The minimum queue allocations are selectable for each transmit queue priority from 4
to 60 cells, in multiples of 4, via software control.
• Support for multicasting to any combination of 12 transmit ports.
• Provides individual enabling for TX and RX of each port separately.
• Provides individual loopback control in each PMD device on board, via software
control.
• Three 24-bit statistics counters per port for receive discarded cells, plus received and
transmitted cells.
• Can generate per-port and per-condition maskable interrupt to the CPU in case of
physical or line error conditions.
25 Mbps PAM Applications
The 25-Mbps port adapter module has 12 ports and is ideal for workgroup links. Figure 9-2
is an example of the 25-Mbps PAM application.
The various 25-Mbps PAMs provide 12 UTP-5 interface connections from the desktop to
the wiring closet.