Product Overview

This chapter provides an overview of the Cisco Metro 1500 series metropolitan area network (MAN) dense wavelength division multiplexing (DWDM) system. This chapter includes the following sections:

Cisco Metro 1500 Series System

The Cisco Metro 1500 series system is a high-performance, wavelength division multiplexer for bidirectional point-to-point data communication. It is designed for communication over optical links in which different devices or applications are communicating over multiple fibers. Using wavelength conversion, several devices can communicate while being connected over one duplex fiber or two single fibers.

The Cisco Metro 1500 series is a modular system. The base configuration consists of a primary chassis which holds up to eight Wavelength Channel Modules (WCM), a Network Element Management Interface module (NEMI), a Multiplexer module (MUX), a Demultiplexer module (DMX) and an optional Remote Switch Module (RSM).

In-service upgrades allow the channel capacity of the Cisco Metro 1500 series system to be expanded in increments of eight WCM channels through the addition of extension chassis. A maximum of three extension chassis (designated A through C) can be added to bring the total channel capacity of the Cisco Metro 1500 series system to 32 WCM channels housed in four chassis.

Cisco recommends that you arrange the extension chassis under the primary chassis as shown in Figure 1-1 and Figure 1-2. The Cisco Metro 1500 series Network Management System (NMS) is connected to external management systems using standard internet protocols. Physical connection to the network is achieved using the ethernet port or the serial port provided on each NEMI module. The interface to an external NMS is provided through SNMP.

NEMI and DEMI Modules

The network element management interface (NEMI) is a plug-in module that is inserted into the Cisco Metro 1500 series primary chassis (16 channel system) and extension chassis B (32 channel system). This interface uses Internet protocols to provide management and configuration capabilities. A NEMI network management system can be connected through an ethernet connection to a computer or local area network. An EIA/TIA-232 port is available on the panel of a NEMI, which can be used for serial-based setup and can be configured to deliver serial- or modem-based Internet protocol connectivity and management with Point-to-Point Protocol (PPP) support.

The device element management interface (DEMI) is a plug-in module that can be inserted into extension chassis A (16 channel system) and extension chassis C (32 channel system) of the Cisco Metro 1500 series. This interface provides status and configuration capabilities. Both the DEMI and its NEMI are connected with an external bus cable. This configuration unites management and control of both chassis into a single unit.

16 Channel Configuration

The Cisco Metro 1500 series system leaves the factory configured as a 16 channel system. It consists of the primary chassis and extension chassis A. The primary chassis includes the NEMI module and extension chassis A holds the DEMI module. Both the NEMI and the DEMI have to be interconnected using an external bus cable. See Figure 1-1.

Figure 1-1: 16 Channel Configuration

The NEMI together with the DEMI can control up to 16 wavelength channel modules (WCMs). Only the NEMI needs to be configured. See "System Configuration."

32 Channel Configuration

To configure a 32 channel system, you need to interconnect two 16 channel systems. The 32 channel system consists of two NEMIs and two DEMIs in a total of four chassis.

The NEMI in the primary chassis is connected using an external bus cable to the DEMI in extension chassis A. The NEMI in extension chassis B is connected using an external bus cable to the DEMI in extension chassis C.

A final interconnection between the NEMI in the primary chassis and the NEMI in extension chassis B, combine the two independent 16 channel units into a single 32 channel management unit.

This interconnection is called an Inter-NEMI Network Connection (INNC). It can be made using either the ethernet ports using an ethernet X-cable, or the serial ports using a LapLink cable on each NEMI module. See Figure 1-2.

Figure 1-2: 32 Channel Configuration

Note The choice of the INNC connection method used between the NEMI modules determines the alternate interconnection method that is available for later connection of the NEMIs to the network.

When two 16 channel units are interconnected using an INNC, the NEMI in the primary chassis is designated the NEMI-Master and the NEMI in extension chassis B is designated the NEMI-Slave.

An INNC allows management and configuration control information to pass bi-directionally between the two NEMI modules. When properly configured, logging into either the NEMI-Master or the NEMI-Slave will present identical views of a single 32 Channel management unit.

In this configuration, both the NEMI-Master and the NEMI-Slave need to be configured. See "System Configuration."

Note EIA/TIA-232 and EIA/TIA-449 were formerly known as recommended standards RS-232 and RS-449 before their acceptance by the Electronic Industries Alliance (EIA) and Telecommunications Industry Association (TIA).

The NEMI runs Linux 2.0.35. Linux starts automatically when the system is powered up. The system is typically ready for operation about 20 seconds after power up.

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