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Should we choose SFP GLC-LH-SM or SFP GLC-LH-SMD fiber optic module?
Among the many different SFP modules, sometimes you may feel confused. Because the difference of some SFP modules is very small, for example, Cisco SFP GLC-LH-SM and Cisco SFP GLC-LH-SMD. If you can’t understand the difference between these two Cisco SFP modules, you don’t know which one to choose for your Cisco switch. In this article, we are going to compare GLC-LH-SM with GLC-LH-SMD.
SFP GLC-LH-SM
The SFP GLC-LH-SM is a replaceable optical transceiver module that transmits data rates of 1 Gbps. And it is compatible with IEEE 802.3 1000BASE-LX / LH standard. It supports a maximum distance of up to 10 km from a single-mode fiber optic cable with a wavelength of 1310 nm. This module can also be used for short network extension through multimode optical fiber cable (550 meters).
Attributes:
Connector: LC duplex
Tx laser output power: -9.5 ~ -3dBm
The sensitivity of the receiver is <-23dBm
Commercial model temperature range: 0 to 70 degrees Celsius (32 to 158 degrees Fahrenheit)
DOM monitoring support: No
Cisco SFP GLC-LH-SMD
SFP GLC-LH-SM is a replaceable optical transceiver module that transmits data rate of 1 Gbps. This SFP can support single-mode and multimode optical fibers.
Other features:
Connector: LC duplex
Tx laser output power: -9.5 ~ -3dBm
Receiving sensitivity <-23dBm
Commercial model temperature range: 0 to 70°C (32 to 158°F)
DOM monitoring support: Yes
The difference between GLC-LH-SM and GLC-LH-SMD
The difference between SFP GLC-LH-SM and SFP GLC-LH-SMD is that SFP GLC-LH-SMD has an additional letter “D”. What does “D” stand for?
“D” in GLC-LH-SMD module has additional support for digital optical monitoring (DOM) capability. From the features mentioned above, SFP GLC-LH-SMD can support DOM function while SFP GLC-LH-SM cannot. DOM provides a diagnostic monitoring interface for optical receiver modules. DOM supports monitoring optical output power, optical input power, temperature, laser bias current and receiver voltage. When DOM is enabled, the system monitors the temperature and signal strength for the optical receiver modules on the specified ports. Console messages and syslog messages are sent when optical operating conditions fall below or exceed thresholds recommended by the SFP manufacturer.
As a result, if the system we want to install the sfp module on has the ability to read the information, we can use the GLC-LH-SMD model, and if we only install it on a system like a media converter and we don’t need monitoring, we can use the GLC model. – Use LH-SM.
Arionet is a producer of all kinds of fiber optic cables in Iran.
