Cisco GLC-LH-SMD is one of the most popular optical modules in the present times. Want to know all about this amazing wired connectivity solution? Then, read on to find the basics about Cisco GLC-LH-SMD optical module.

GLC-LH-SMD
1. Basics of GLC-LH-SMD optical modules

Important module parameters of Cisco GLC-LH-SMD

The Cisco GLC-LH-SMD Optical Module is an MSA protocol compliant connectivity solution that connects a Gigabit Ethernet port or slot to an optical fiber network. It is also known as 1000BASE-LX / LH SFP transceiver. The following is the table of parameters of this optical module.


Optical module model
GLC-LH-SMD


Package type
SFP

Center wavelength
1310nm

Rate
1000Mbps

Interface
Duplex LC

The maximum transmission distance
10km

Laser type
FP 1310nm

Fiber type
MMF/SMF

DOM function
Support

Transmit optical power
-9～-3dBm

Receiving sensitivity
-21dBm

Commercial temperature
0～70℃

Important applications of Cisco GLC-LH-SMD

Cisco GLC-LH-SMD optical module is compatible with various optical transmission networks, and applications following protocols such as Fiber Channel, SDH/SONET/ATM, Gigabit Ethernet, and others. This transceiver is functional across variety of switches, routers and server interfaces too.

Cisco GLC-LH-SMD compatible switch models

Listed here are a few switch models compatible with Cisco GLC-LH-SMD . You can find more about the compatible switches at the detailed page of the GLC-LH-SMD optical module

Switch model

2960S-F48TS-L
Cisco WS-C3750X-48PC
WS-X4624-SFP-ECisco 6500
N9K-C92160YC-XCisco 3900
WS-C2960X-48LPD-L
WS-C3560E-48PD
WS-C3650-48FS
Cisco WS-C4500X-40X-ES
C6800-32P10G(-XL)Cisco Nexus
SPA-2X1GE-V2Cisco ASR 9000
WS-C2960XR-48TD-I
WS-C3650-48TQ
IE-2000-16PTC-G-ECisco 4500
WS-X4448-GB-SFPCisco 6500

2. Comparison between Cisco GLC-LH-SM and GLC-LH-SMD

Similarities

Cisco GLC-LH-SM and GLC-LH-SMD are similar in many features. Both of these deliver data transmission reach of 10km at the input wavelength of 1310nm. They are fully compatible with IEEE 802.3 1000BASE-LX/LH standard and thus they can be used interchangeably. At Cozlink, you can find both of these priced at $7.

Differences

The most obvious difference between Cisco GLC-LH-SM and GLC-LH-SMD is whether it has a DDM support or not.
3. DDM Function – Unique aspect of GLC-LH-SMD Transceiver

The letter “D” in GLC-LH-SMD stands for digital diagnostic monitoring function also known as digital optical monitoring (DOM). This feature is introduced as per Multi-source Agreement (MSA) SFF-8472. It serves following purposes:

a. Component Monitoring

Optical Transceivers need monitoring of these parameters so that these crucial connectivity solutions are not overworked and fall prone to fault. These parameters are – laser bias current, transceiver supply voltage, transceiver temperature, average optical power, average optical power transmitted and received, and optical modulation amplitude. If any of these parameters are exceeded, the DDM system warns the system about failure of compliance.

b. Fault Identification and Isolation

DDM enables easy fault isolation and their identification in particular location of optical network system. It issues status flags and using these flags in addition to parametric monitoring data that DDM produces, one can pick the faulty part and ascertain the reason for failed link in no time.

c. Failure prediction in advance

DDM is effective in identifying two basic failures common with optical transceivers such as frequent errors and breakdowns. Based on the transceiver performance parameters report, DDM can predict impending failures of the fiber optic links. Transmitter performance is responsible for breakdowns and frequent errors are attributed to the operating conditions of the transceiver. The knowledge about these conditions can make the failure prevention easier.
4. How Cisco GLC-LH-SMD, GLC-SX-MMD and GLC-ZX-SM optical modules are different

The following table enlists the important parameters of Cisco GLC-LH-SMD, GLC-SX-MMD, and GLC-ZX-SM modules. The table reveals that all three modules are same in delivering data transmission rate, commercial temperature range applicable and interface type. Also, their naming suggests that only GLC-LH-SM does not have DDM support while the other two have this feature.

All these modules are good in their area of working. You can pick any of these after deciding your network requirements.

If you require an optical module that can transmit data up to a distance of 70km, GLC-ZX-SM is worth recommending and for shorter data reach, say up to 550m, you can go for GLC-ZX-SM. And if DOM feature is your urgent requirement, you can consider buying GLC-SX-MMD.

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5. GLC-LH-SM vs. SFP-GE-L: Know the Difference

GLC-LH-SM SFP Module

GLC-LH-SM is the name given by Cisco for transceiver suitable for long haul networks. This transceiver is unique in the sense that it can operate on both single and multimode fibers by employing a mode conditioning patch cable. This hot-swappable connectivity option is compliant with IEEE802.3z 1000BASE-LX standard, and can deliver data transmission reach of 10km and 550m on single mode and multimode fibers respectively. Here are the basic parameters of GLC-LH-SM tabulated:

Modules
Cisco GLC-LH-SM

Interface
LC duplex

Wavelength
1310nm

Tx power
-9.5 ~ -3dBm

Receiver Sensitivity
-23dBm

DOM Support
No

Temperature Range
32℉to 158℉ (0℃to 70℃)

SFP-GE-L SFP Module

SFP-GE-L transceiver is similar to GLC-LH-SM transceiver on many aspects. Compliant with IEEE 802.3z 1000BASE-LX, this transceiver, like a Cisco 1000BASE-LX/LH Ethernet transceiver is also made compatible with many Gigabit Ethernet applications. The SFP-GE-L transceiver also can deliver data connectivity across both single mode and multimode fibers up to a distance of 10 km and up to 550 m respectively.


Modules
Cisco SFP-GE-L

Interface
LC duplex

Wavelength
1310nm

Tx power
-9.5 ~ -3dBm

Receiver Sensitivity
-23dBm

DOM Support
Yes

Temperature Range
23℉ to 185℉ (-5℃ to 85℃)

Notes: Both GLC-LH-SM and SFP-GE-L modules require mode conditioning patch cables when used across 1000BASE-LX/LH applications connected with OM1, and OM2 fiber cables of FDDI grade.

Speaking about differences, the SFP-GE-L SFP transceiver comes with DOM (digital optical monitoring) whereas GLC-LH-SM lacks this feature. Both are different on account of operating temperature range too. SFP-GE-L module is designed to work at extended temperature range of -5℃ to 85℃ while Cisco GLC-LH-SM is operational at the commercial temperature range of 0℃ to 70℃.

6. How 1000BASE- LX, LH and LX/LH are different from each other?

All 1000BASE-LX, 1000BASE-LH and 1000BASE-LX/LH imply Gigabit Ethernet transmissions. Among them, only the 1000BASE-LX is a standard, while the other two terms - 1000BASE-LH and 1000BASE-LX/LH have come into fashion due to their popularity amongst vendors. There are other transmission standards such as 1000BASE-LX10, 1000BASE-EX and 1000BASE-ZX too that are found to be useful in long haul networks. Their differences are more clearly illustrated in the table below:

7. When is EOL declared for Cisco GLC-LH-SM

Cisco GLC-LH-SM which is an LX/LH GE SFP with LC connector has reached its EOL i.e. End of Life. It is fully replaced by another 1000BASE-LX/LH transceiver Cisco GLC-LH-SMD which comes with DOM and works with both SMF and MMF at input wavelength of 1310nm.

With change in popularity and demand, Cisco scraps certain GE SFP Modules. This end of life and end of sale information about the abandoned modules is available at:

https://www.cisco.com/c/en/us/products/collateral/interfaces-modules/transceiver-modules/eol_c51-698060.html

For those looking for Cisco compatible GLC-LH-SMD, Cozlink is the right place to be. This OEM produces Cisco equipment compatible transceivers and other connectivity solutions.

Source: https://www.cozlink.com/modules-a272-275-273/article-74053.html