Getting ready to run SMF for a new office buildout. Does this transceiver require a simplex or duplex patch cable, and what connector type?

This optical module utilizes a standard Duplex LC connector interface. You will need a dual-strand Single-Mode Fiber (SMF) patch cable for the dedicated Tx/Rx ports to achieve the maximum 20km transmission distance.

I need to ensure this optical module supports legacy protocols for our metro Ethernet setup. Is it compliant with standard IEEE Gigabit specs?

Yes, the LS-SM311G-20C fully supports IEEE 802.3z for Gigabit Ethernet, as well as IEEE 802.3ah-2004. It also features SFF-8472 compliance, allowing for real-time Digital Optical Monitoring (DOM/DDM) metrics directly through your switch interface.

Our outdoor cabinets in Arizona get super hot. This model is 0-70°C commercial grade. Do you have an industrial version that handles extreme temps?

You’ll definitely want our LS-SM311G-20I version for that deployment. It shares the exact same 1310nm 20km optical specs but features an industrial operating temperature range of -40°C to 85°C, perfect for harsh base station backhaul environments.

Hi, we run a mix of Cisco and Fortinet switches in our rack. Will this LS-SM311G-20C play nice with both brands without throwing errors?

Absolutely! This 1G SFP is fully MSA compliant and heavily tested for OEM compatibility across major brands, including Cisco, Fortinet, Juniper, and Dell. It’s truly plug-and-play with zero vendor-lock issues.

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Cisco GLC-LH-SM-20 Compatible LINK-PP 1G SFP 1310nm 20km Duplex LC DOM SMF Optical Transceiver Module

Name: Cisco GLC-LH-SM-20 Compatible LINK-PP 1G SFP 1310nm 20km Duplex LC DOM SMF Optical Transceiver Module
Brand: LINK-PP
SKU: 219270
Price: 4.3 USD
Availability: InStock
Rating: 4.9 (16 reviews)

# 219270

Product: Cisco GLC-LH-SM-20 Compatible LINK-PP 1G SFP 1310nm 20km Duplex LC DOM SMF Optical Transceiver Module
SKU: 219270
P/N: LS-SM311G-20C
Price: $ 5
Stock: 617 in Stock
Sold: 561
Product URL: https://www.l-p.com/products/476756.htm

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Manufacture: LINK-PP

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Compatible:: Cisco; LINK-PP; Alcatel-Lucent; Arista; Avaya; Brocade; Calix; Ciena; Dell; Extreme; FS; Fortinet; Generic; H3C; IBM; Intel; Juniper; Mikrotik; NVIDIA/Mellanox; Syrotech

Compatible P/N:: SFP1G-SX-31 | 2km; SFP1G-SX-31-I | 2km; GLC-LH-SM | 10km; GLC-LH-SMD | 10km; GLC-LH-SM-20 | 20km; GLC-LX-SM-RGD | 20km; GLC-EX-SM1550-40 | 40km; GLC-EX-SMD | 40km; MGBLH1 | 40km; GLC-ZX-SM | 80km; GLC-ZX-SM-RGD | 80km; GLC-EZX-SM-100 | 100km; GLC-EZX-SM-120 | 120km; GLC-EZX-SM-160 | 160km

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Cisco GLC-LH-SM-20 Compatible LINK-PP 1G SFP Specifications

The Cisco GLC-LH-SM-20 Compatible LINK-PP module is a high-performance commercial-grade 1G SFP transceiver tailored for standard gigabit ethernet operations. Operating over a 1310nm wavelength, it efficiently delivers high-speed data transmission up to 20km across single-mode fiber infrastructure. Equipped with a duplex LC interface, this hot-pluggable optical module integrates seamlessly into standard network switches, ensuring dependable link performance.

Cisco Part Number	GLC-LH-SM-20	Vendor Name	LINK-PP
Form Factor	SFP	Max Data Rate	1.25Gbps
Wavelength	1310nm	Max Cable Distance	20km
Connector	Duplex LC	Media	SMF
Transmitter Type	FP	Receiver Type	PIN
TX Power	-9 to 0dBm	RX Power	-23 to -1dBm
Receiver Sensitivity	-23dBm	DOM Support	Yes
Operating Temperature Range	0 to 70°C	Protocols	SFF-8472 MSA Compliant, IEEE 802.3ah-2004, IEEE 802.3z

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Q: Getting ready to run SMF for a new office buildout. Does this transceiver require a simplex or duplex patch cable, and what connector type? By J***z on 2026-05-19

A: This optical module utilizes a standard Duplex LC connector interface. You will need a dual-strand Single-Mode Fiber (SMF) patch cable for the dedicated Tx/Rx ports to achieve the maximum 20km transmission distance. By admin on 2026-05-20
Q: I need to ensure this optical module supports legacy protocols for our metro Ethernet setup. Is it compliant with standard IEEE Gigabit specs? By P***s on 2026-04-06

A: Yes, the LS-SM311G-20C fully supports IEEE 802.3z for Gigabit Ethernet, as well as IEEE 802.3ah-2004. It also features SFF-8472 compliance, allowing for real-time Digital Optical Monitoring (DOM/DDM) metrics directly through your switch interface. By admin on 2026-04-07
Q: Our outdoor cabinets in Arizona get super hot. This model is 0-70°C commercial grade. Do you have an industrial version that handles extreme temps? By J***n on 2025-11-28

A: You’ll definitely want our LS-SM311G-20I version for that deployment. It shares the exact same 1310nm 20km optical specs but features an industrial operating temperature range of -40°C to 85°C, perfect for harsh base station backhaul environments. By admin on 2025-11-28
Q: Hi, we run a mix of Cisco and Fortinet switches in our rack. Will this LS-SM311G-20C play nice with both brands without throwing errors? By J***z on 2025-09-13

A: Absolutely! This 1G SFP is fully MSA compliant and heavily tested for OEM compatibility across major brands, including Cisco, Fortinet, Juniper, and Dell. It’s truly plug-and-play with zero vendor-lock issues. By admin on 2025-09-13

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J***g

Venezuela

Verified Purchase

4 .0

2026-03-03

Standard shipping to London took extra days, but 1310nm 20km SFP is solid.

64 Helpful vote Comments

L***r

United Arab Emirates

Verified Purchase

5 .0

2026-03-01

Flawless SFP module for fiber SMF deployments.

148 Helpful vote Comments

W***l

Ireland

Verified Purchase

5 .0

2026-02-21

Great 1.25Gbps throughput for home NAS.

74 Helpful vote Comments

W***h

Brazil

Verified Purchase

5 .0

2025-11-03

Replaced old optics with these duplex LC SMF transceivers for our Frankfurt server racks. The 20km distance covers our metro links effortlessly. Unbeatable price for Dell and Juniper OEM compatibility!

150 Helpful vote Comments

W***n

Panama

Verified Purchase

5 .0

2025-10-02

Affordable gigabit optical modules for b2b buyers.

159 Helpful vote Comments

J***s

Poland

Verified Purchase

5 .0

2025-09-19

Great IEEE 802.3z compliant SFP for Toronto enterprise procurement. Reliable PIN receiver specs.

83 Helpful vote Comments

J***z

Germany

Verified Purchase

5 .0

2025-09-10

Accurate DOM readings, superb network equipment value.

222 Helpful vote Comments

D***n

Brazil

Verified Purchase

5 .0

2025-07-25

Solid 20km transceiver for long distance links.

60 Helpful vote Comments

R***r

Singapore

Verified Purchase

5 .0

2025-07-20

Tested the LS-SM311G-20C module in outdoor cabinets across Texas. Despite the commercial 0-70°C rating, it handled the summer heat perfectly. Excellent IEEE 802.3z protocol support for our base station backhaul!

186 Helpful vote Comments

A***n

Taiwan, Province of China

Verified Purchase

5 .0

2025-06-30

Runs cool at 0-70°C commercial temp. ❄️

239 Helpful vote Comments

D***n

Sweden

Verified Purchase

5 .0

2025-05-30

Purchased bulk LS-SM311G-20C transceivers for Chicago office routing. Clean duplex LC connection! (o_o)

139 Helpful vote Comments

S***z

Taiwan, Province of China

Verified Purchase

5 .0

2025-05-16

Duplex LC clicks in tight, zero issues.

63 Helpful vote Comments

J***h

Tunisia

Verified Purchase

5 .0

2025-04-12

Good Tx/Rx power balance. Ideal 1310nm optical transceiver for indoor rack setups. ¯_(ツ)_/¯

133 Helpful vote Comments

A***l

Austria

Verified Purchase

5 .0

2025-04-09

Upgraded my home gigabit NAS setup in California using this 1G fiber optic module. The Tx/Rx power levels are stable, and the FP laser runs cool. Highly recommend for enterprise-grade homelabs.

67 Helpful vote Comments

D***z

Dominican Republic

Verified Purchase

5 .0

2025-01-28

Tested in Extreme switches, this 1.25Gbps module handles our 15km warehouse links perfectly.

112 Helpful vote Comments

M***a

Colombia

Verified Purchase

5 .0