Installation guide

Chapter 4 Configuring the Gigabit Ethernet Ports
Connecting To an SFP Module
4-14
Catalyst 2984G, 2948G-GE-TX, and 2980G Switch Hardware Installation Guide
78-6286-04
Note For information about the Coarse Wave Division Multiplexing (CWDM), refer to
the Cisco CWDM GBIC and CWDM SFP Installation Note.
The 1000BASE-T (copper) SFP module is used to establish a Gigabit Ethernet
connection through a Category 5 Category 5 cable.
Use only Cisco SFP modules on the Catalyst 2948G-GE-TX switch. Each SFP
module has an internal serial EEPROM that is encoded with security information.
This encoding provides a way for Cisco to identify and validate that the SFP
module meets the requirements for the switch.
For more information about these SFP modules, refer to your SFP module
documentation and to the Cisco Small Form-Factor Pluggable Modules
Installation Notes (not orderable but is available on Cisco.com.)
Table 4-5 Fiber-Optic SFP Module Port Cabling Specifications
SFP Module
Wavelength
(nanometers) Fiber Type
Core Size
(micron)
Modal
Bandwidth
(MHz/km) Cable Distance
1000BASE-SX 850 MMF 62.5
62.5
50.0
50.0
160
200
400
500
722 ft (220 m)
902 ft (275 m)
1640 ft (500 m)
1804 ft (550 m)
1000BASE-LX/LH 1300 MMF
1
SMF
1. A mode-conditioning patch cord is required. Using an ordinary patch cord with MMF, 1000BASE-LX/LH SFP modules, a
a short link distance can cause transceiver saturation, resulting in an elevated bit error rate (BER). When using the LX/L
SFP module with 62.5-micron diameter MMF, you must also install a mode-conditioning patch cord between the SFP modu
and the MMF cable on both the sending and receiving ends of the link. The mode-conditioning patch cord is required for li
distances greater than 984 feet (300 m).
62.5
50.0
50.0
9/10
500
400
500
—
1804 ft (550 m)
1804 ft (550 m)
1804 ft (550 m)
6.2 mi (10 km)
1000BASE-ZX 1550 SMF 9/10 — 43.4 to 62 mi (70 to
100 km)
2
2. 1000BASE-ZX SFP modules can reach up to 100 km by using dispersion-shifted SMF or low-attenuation SMF; the distan
depends on the fiber quality, the number of splices, and the connectors.