Will this SFP module work with our older Cisco Catalyst and newer Arista switches without triggering any unsupported transceiver errors?

Absolutely. The LS-SM311G-40I is fully MSA compliant and extensively tested for 100% OEM compatibility with Cisco, Arista, and over 15 other major networking brands. No vendor lock-in warnings or CLI bypasses needed.

Can I use multimode fiber with this 1310nm 40km transceiver, or does it strictly require single-mode fiber (SMF)?

This specific module requires Single-Mode Fiber (SMF) to achieve the 40km transmission distance utilizing its 1310nm DFB laser. If your infrastructure relies on MMF, you will need to check out our 1000BASE-SX short-reach versions instead.

Does this 1.25G DFB transceiver support DOM/DDM and comply with IEEE 802.3ah-2004 for our telecom backhaul?

Definitely. It fully complies with IEEE 802.3ah-2004 and SFF-8472 protocols. The integrated Digital Optical Monitoring (DOM) allows your network engineers to track real-time receiver sensitivity, laser power, voltage, and internal temperature directly from your switch interface.

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Cisco GLC-EX-SMD Compatible LINK-PP 1.25G SFP 1310nm 40km Duplex LC DOM SMF Optical Transceiver Module (Industrial)

Name: Cisco GLC-EX-SMD Compatible LINK-PP 1.25G SFP 1310nm 40km Duplex LC DOM SMF Optical Transceiver Module (Industrial)
Brand: LINK-PP
SKU: 223997
Price: 10.32 USD
Availability: InStock
Rating: 5 (39 reviews)

# 223997

Product: Cisco GLC-EX-SMD Compatible LINK-PP 1.25G SFP 1310nm 40km Duplex LC DOM SMF Optical Transceiver Module (Industrial)
SKU: 223997
P/N: LS-SM311G-40I
Price: $ 12
Stock: 839 in Stock
Sold: 612
Product URL: https://www.l-p.com/products/476762.htm

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Manufacture: LINK-PP

P/N: LS-SM311G-40I

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

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-EX-SMD Compatible LINK-PP 1.25G SFP Specifications

The Cisco GLC-EX-SMD Compatible LINK-PP module is an industrial-grade 1.25G SFP transceiver engineered for optimal performance. Operating at a 1310nm wavelength over single-mode fiber, it supports transmission distances up to 40km. Featuring a duplex LC interface and full Digital Optical Monitoring, this hot-pluggable module operates reliably across a wide temperature range from -40°C to 85°C.

Cisco Part Number	GLC-EX-SMD	Vendor Name	LINK-PP
Form Factor	SFP	Max Data Rate	1.25Gbps
Wavelength	1310nm	Max Cable Distance	40km
Connector	Duplex LC	Media	SMF
Transmitter Type	DFB	Receiver Type	PIN
TX Power	-5 to 0dBm	RX Power	-23 to -1dBm
Receiver Sensitivity	<-23dBm	DOM Support	Yes
Operating Temperature Range	-40 to 85°C	Protocols	SFF-8472 MSA Compliant, IEEE 802.3ah-2004

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Q: Will this SFP module work with our older Cisco Catalyst and newer Arista switches without triggering any unsupported transceiver errors? By J***s on 2026-04-08

A: Absolutely. The LS-SM311G-40I is fully MSA compliant and extensively tested for 100% OEM compatibility with Cisco, Arista, and over 15 other major networking brands. No vendor lock-in warnings or CLI bypasses needed. By admin on 2026-04-08
Q: Can I use multimode fiber with this 1310nm 40km transceiver, or does it strictly require single-mode fiber (SMF)? By R***k on 2026-03-14

A: This specific module requires Single-Mode Fiber (SMF) to achieve the 40km transmission distance utilizing its 1310nm DFB laser. If your infrastructure relies on MMF, you will need to check out our 1000BASE-SX short-reach versions instead. By admin on 2026-03-14
Q: Does this 1.25G DFB transceiver support DOM/DDM and comply with IEEE 802.3ah-2004 for our telecom backhaul? By D***r on 2026-03-05

A: Definitely. It fully complies with IEEE 802.3ah-2004 and SFF-8472 protocols. The integrated Digital Optical Monitoring (DOM) allows your network engineers to track real-time receiver sensitivity, laser power, voltage, and internal temperature directly from your switch interface. By admin on 2026-03-05

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M***e

Denmark

Verified Purchase

5 .0

2026-05-29

Using this 40km optical transceiver for a remote telecom base station backhaul. Plugged it into a Ciena router and the link came up instantly. Superb receiver sensitivity ensures stable long-haul Gigabit connectivity.

24 Helpful vote Comments

M***z

Chile

Verified Purchase

5 .0

2026-05-21

Perfect for our Cisco campus fiber network!

167 Helpful vote Comments

D***n

United States

Verified Purchase

5 .0

2026-03-15

Awesome OEM compatibility and fast batch deployment.

44 Helpful vote Comments

M***t

Sweden

Verified Purchase

4 .0

2026-01-25

Box was slightly crushed on arrival, but the 1.25G industrial SFP works perfectly.

189 Helpful vote Comments

J***z

United States

Verified Purchase

5 .0

2026-01-02

Used these for a 38km base station backhaul. The DFB laser holds up great.

171 Helpful vote Comments

J***s

France

Verified Purchase

5 .0

2025-11-10

No issues syncing with FS and Mellanox.

92 Helpful vote Comments

D***k

Netherlands

Verified Purchase

5 .0

2025-09-20

Cheap and reliable 1.25G fiber optic transceiver.

175 Helpful vote Comments

S***r

India

Verified Purchase

5 .0

2025-07-15

Bought a batch for traffic control outdoor cabinets. Extreme temps don't bother these modules.

162 Helpful vote Comments

B***z

Denmark

Verified Purchase

5 .0

2025-07-13

Survived -30C in our remote base station!

185 Helpful vote Comments

D***z

Malaysia

Verified Purchase

5 .0

2025-07-12

Needed a reliable MSA compliant transceiver for an outdoor IP camera mesh. This industrial wide-temp SFP handles freezing nights perfectly. It synced with our mixed Alcatel environment without vendor lock-in complaints. Brilliant hardware. ❄️

160 Helpful vote Comments

A***n

Macao

Verified Purchase

5 .0

2025-07-09

Works perfectly in my home lab router.

195 Helpful vote Comments

C***a

Panama

Verified Purchase

5 .0

2025-06-27

Plug and play duplex LC SMF module.

39 Helpful vote Comments

T***g

Argentina

Verified Purchase

5 .0

2025-06-03

We run industrial automation networks where summer enclosure temps hit 70°C. These rugged 1.25Gbps single-mode transceivers haven't flinched. The duplex LC connectors lock tight, and the 1310nm signal stays crystal clear over 20 miles.

150 Helpful vote Comments

S***z

Denmark

Verified Purchase

5 .0

2025-05-03

Upgraded our enterprise NAS network. Smooth 1G SFP integration with Netgear and H3C switches.

101 Helpful vote Comments

M***n

Brazil

Verified Purchase

5 .0

2025-03-22

Much cheaper than original Cisco 1G SFPs but performs exactly the same in production.

175 Helpful vote Comments

A***g

Kenya

Verified Purchase

5 .0

2025-02-26

Deployed 50 of these LS-SM311G-40I modules across a massive campus fiber ring. OEM compatibility with Brocade and Extreme switches is 100% spot on. Real-time DOM monitoring is a lifesaver for our ops!

199 Helpful vote Comments

R***l

Thailand

Verified Purchase

5 .0

2025-02-20

Excellent value for IEEE 802.3ah-2004 deployments. Works right out of the box with Dell.

24 Helpful vote Comments

R***n

Bolivia

Verified Purchase

5 .0

2025-02-14

Stable 1310nm wavelength connection over 35km link.

105 Helpful vote Comments

M***z

Japan

Verified Purchase

5 .0

2024-12-02

Great industrial grade SFP for outdoor enclosures.

124 Helpful vote Comments

C***n

Canada

Verified Purchase

5 .0

2024-06-05

They announced all the Optical Transceiver Modules are tested before shippment. From my experience. that's truth. My ordered items are all good.

16 Helpful vote Comments

Y***e

Hong Kong

Verified Purchase

5 .0

2024-04-20

Received what I ordered in a timely manner. Products arrived well packed and in perfect condition.

28 Helpful vote Comments

T***y

Russian Federation

Verified Purchase

5 .0

2024-03-20

It is exactly what I needed for my project.

103 Helpful vote Comments

J***n

India

Verified Purchase

5 .0

2024-03-13

Great price, outstanding service.

52 Helpful vote Comments

M***a

United Kingdom

Verified Purchase

5 .0

2023-12-11

l-p.com is the best optical transceiver store, which i know. I received perform well.

40 Helpful vote Comments

T***i

Japan

Verified Purchase

5 .0

2023-11-29

Great price and always has what I'm looking for.

99 Helpful vote Comments

B***r

Indonesia

Verified Purchase

5 .0

2023-11-05

Good experience--products were shipped right away--exactly what we needed.

68 Helpful vote Comments

U***n

Malaysia

Verified Purchase

5 .0

2023-11-01

Thanks for your wonderful service!Will come back again soon.

26 Helpful vote Comments

D***r

Spain

Verified Purchase

5 .0

2023-10-04

No fuss, no drama - the product arrived on time, and worked perfectly.

129 Helpful vote Comments

A***y

Australia

Verified Purchase

5 .0

2023-10-03

Placed a few orders over the years with Link-PP. Their customers service have been brilliant and very helpful in the past and I always found the prices very competitive.

49 Helpful vote Comments

D***g

Indonesia

Verified Purchase

5 .0

2023-09-15

Great price for product and shipping. Fast shipping. Will shop again!

26 Helpful vote Comments

S***n

United Kingdom

Verified Purchase

5 .0