Chapter 2 Overview
Front-Panel Description
2-16
Catalyst 2950 Desktop Switch Hardware Installation Guide
78-11157-05
Use only Cisco-approved SFP modules on the Catalyst 2950 LRE switch.
Note
Cisco-approved SFP modules have a serial EEPROM that contains the module
serial number, the vendor name and ID, a unique security code, and cyclic
redundancy check (CRC). When an SFP module is inserted in the switch, the
switch software reads the EEPROM to check the serial number, vendor name, and
vendor ID and recomputes the security code and CRC. If the serial number, the
vendor name or ID, security code, or CRC is invalid, the switch places the
interface in an error-disabled state.
Note
If you are using a non-Cisco approved SFP module, remove the module from the
switch, and replace it with a Cisco-approved module.
For more information about these SFP modules, refer to your SFP module
documentation.
Table 2-2
Cabling Stipulations for SFP Modules
SFP
Module
62.5/125 micron
Multimode
850 nm
1
Fiber
1.
nm = nanometer
50/125 micron
Multimode
850 nm Fiber
62.5/125 micron
Multimode
1310 nm Fiber
50/125 micron
Multimode
1310 nm Fiber
9/125 micron
Single-mode
1310 nm fiber
9/10 micron
Single-mode
1550 nm fiber
SX
275 m
2
at
200 Mhz
3
-km
4
2.
m = meter
3.
Mhz = megahertz
4.
km = kilometer
550 m at
500 Mhz-km
—
—
—
—
LX
—
—
550 m at
500 Mhz-km
550 m at
400 Mhz-km
10 km
—
ZX
—
—
—
—
—
70 to 100 km
(43.4 to
62 miles)
5
5.
You need to use dispersion-shifted or low-attenuation single-mode fiber (SMF) for connections of up to 100 kilometers
(328,100 feet). The actual distance depends on the fiber quality, the number of splices, and the type of connectors used.
