Cisco Systems 3550 manual GBIC Module Slots, LEDs, System LED

Chapter 1 Product Overview

Front-Panel Description

GBIC Module Slots

You cannot configure speed or duplex mode on GBIC slots, but for certain types of GBICs, you can configure speed to not negotiate (nonegotiate) if connected to a device that does not support autonegotiation.

The GBIC module slots support these modules to provide flexibility in media and distance options:

•1000BASE-T GBIC module for copper connections of up to 328 feet (100 meters).

•1000BASE-SX GBIC module for fiber-optic connections of up to 1,804 feet (550 meters) multimode only.

•1000BASE-LX/LH GBIC module for fiber-optic connections of up to 32,810 feet (10 kilometers) single mode or 1,804 feet (550 meters) multimode.

•1000BASE-ZX GBIC module for fiber-optic connections of up to 328,000 feet (100 kilometers) single mode only.

•GigaStack GBIC module for creating a 1-Gbps stack configuration of up to nine supported switches. The GigaStack GBIC supports one full-duplex link (in a point-to-point configuration) or up to nine half-duplex links (in a stack configuration) to other Gigabit Ethernet devices. When you use the required Cisco proprietary signaling and cabling, the maximum distance for a GigaStack GBIC-to-GigaStack GBIC connection is 3 feet (1 meter).

•Coarse Wave Division Multiplexing (CWDM) GBIC modules for fiber-optic connections of up to 393,719 feet (120 kilometers) single mode only.

Cisco-approved CWDM GBIC modules have a serial EEPROM that contains the module serial number, the vendor name and vendor ID, a unique security code, and cyclic redundancy check (CRC). When a CWDM GBIC module is inserted in the switch, the switch software reads the EEPROM to check the serial number, vendor name and vendor ID, and recompute the security code and CRC. If the serial number, the vendor name or vendor ID, the security code, or CRC is invalid, the switch places the port in an error-disabled state.

For more information about GBICs, see the documentation included with your GBIC module and Related Publications, page xiii, for a list of related documentation.

LEDs

You can use the switch LEDs to monitor switch activity and its performance. Figure 1-3shows the LEDs and the Mode button that you use to select one of the port modes.

All of the LEDs described in this section except the utilization meter (UTIL) are visible on the device manager and through the Network Assistant.

System LED

The system LED shows whether the system is receiving power and is functioning properly. Table 1-2lists the LED colors and their meanings.

Table 1-2 System LED

Color	System Status
Off	System is not powered on.

Catalyst 3550 Switch Hardware Installation Guide

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