14
L2 Managed Switch
Connection
Optical fiber
Optical fiber can be used as a medium for telecommunication and computer networking. It is especially
advantageous for long-distance communications, because light propagates through the fiber with much
less attenuation compared to electrical cables. For short distance applications, such as a network in an
office building, optical fiber permits transmission over longer distances and at higher bandwidths (data
rates) than other forms of communication. Fibers are used instead of metal wires because signals travel
along them with less attenuation and are also immune to electromagnetic interference. There is no cross-
talk between signals in different cables, and no pickup of environmental noise.
SFP Module
SFP module are input/output (I/O) devices that plug into a Gigabit Ethernet port, linking the port with
a 1000BASE-X fiber-optic network. A SFP module possesses a receiver port (RX) and a transmitter port
(TX) that make up one optical interface. To enjoye the required optical reach, users can freely select the
appropriate SFP module over the available optical fiber type such as multi-mode fiber or single-mode fiber.
Multi-mode fibers generally have a larger core diameter, and are used for short-distance communication
links and for applications where high power must be transmitted. Single-mode fibers are used for most
communication links longer than 1,050 meters that is 3,440 feet.
TL-SG5428 and TL-SG5412F are compatible with all kinds of gigabit SFP modules including sigle-mode and
multi-mode. The transmission distance and the type of optical fiber are determined by the SFP module
you choose. Here you are recommanded to choose the SFP modules produced by TP-LINK, which can
perfectly enlarge the bandwidth and extend your network.
Figure 4-3 SFP module
The following table shows the detailed information of two SFP modules (TL-SM311LS and TL-SM311LM)
produced by TP-LINK, which makes you have a round idea about it so as to give you a reference for
choosing the suitable SFP module.
Model
TL-SM311LS
TL-SM311LM
Standards
IEEE 802.3z
CSMA/CD
TCP/IP
IEEE 802.3z
CSMA/CD
TCP/IP
Transmission Media
Single-mode fiber (9/125um)
Multi-mode fiber (50/125um or 62.5/125um)
Transmission Speed
1.25Gbps
1.25Gbps
Transmission Distance
10km
550m
Output Center Wavelength 1310nm
850nm
Note:
For security, please wear an ESD-preventive wrist strap when installing or removing the
SFP module. For detailed information, please refer to
Chapter 3 Lightning Protection
.
