Network Card User Manual

About This Guide xi

• Double-density modem module (DMM)—Each double-density modem card contains 12 DMM

SIMMS. Each DMM SIMM contains 12 digital modems.The Cisco AS5800 has the capability

of terminating up to 1,344 modem connections when equipped with 10 double-density modem

cards and 2 CT3 trunk cards.

• Egress interface—The router shelf interface to a network, such as the Internet or a corporate

intranet or backbone. Supported interfaces include Fast Ethernet, HSSI, FDDI, and ATM

interfaces.

• Front and rear—The front of the dial shelf is defined as the card-insertion side and provides

access to the line cards and the blower assembly. The rear or back of the dial shelf is defined as

the power-entry side and provides access to the filter module and two power-entry modules.

• I/O controller card—The router shelf card containing the system I/O controller.

• Ingress interface—Dial shelf cards that connect to the telco network and contain the necessary

functionality to terminate a telco connection. The ingress interface terminates digital calls at the

dial shelf. The Cisco AS5800 currently supports CE1, CT1 and CT3 ingress interfaces.

• Maintenance bus (MBus)—Used in the dial shelf to monitor –48 VDC from both DC power

supplies using analog isolation circuits.

• Modem card—A printed circuit board that connects to the dial shelf backplane and contains hex

modem module SIMMs. Its primary purpose is conversion between pulse code modulation

(PCM)-encoded analog bitstreams on the backplane TDM bus and packetized digital data on the

backplane interconnect. The modem card terminates incoming analog calls at the dial shelf.

• Network processor card—The router shelf card containing the network processing engine (NPE).

• Online insertion and removal (OIR)—A feature that allows you to insert and remove modules and

cards without interruption to service while the system is powered on.

• Pulse code modulation (PCM)—A specific way of representing an analog waveform in digital

format.

• Power-entry module (PEM)—A –48 VDC power supply module.

• Router shelf—The host route processing functionality for the dial shelf. The router shelf carries

data between the dial shelf and an external network, such as the Internet. Full Cisco IOS software

functionality is provided on the router shelf.

• Time-division multiplexing bus (TDM bus)—A dial shelf proprietary serial telecommunications

backplane that enables multiple channels of data to be transmitted over the same medium. The

TDM bus connects a DS0 channel (from the ingress interface) to an individual modem on the

modem card.

• Trunk card—A printed circuit board that connects to the dial shelf backplane and contains trunk

circuitry, such as CT1 or CE1 interfaces. The trunk card acts as the ingress interface through

which all calls are received, and terminates incoming digital calls at the dial shelf.