Installation guide

Chapter 2 Product Overview
Front-Panel Description
2-8
Catalyst 3550 Multilayer Switch Hardware Installation Guide
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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, refer to the documentation included with
your GBIC module and to Related Publications, page xxi for a list of related
documentation.