Does this transceiver require single-mode or multi-mode fiber, and what connector does it use?

This specific module requires Single-Mode Fiber (SMF) to achieve its optimal transmission distance of up to 20km at a 1310nm wavelength. It features an industry-standard Duplex LC connector interface.

Is this unit fully compliant with standard gigabit ethernet protocols for our legacy setup?

Yes, it fully supports IEEE 802.3z and IEEE 802.3ah-2004 standards, alongside SFF-8472 for digital optical monitoring (DOM), ensuring perfect protocol adaptation with both legacy and modern gigabit Ethernet infrastructures.

Will these work with my Cisco catalyst switches without throwing any unsupported transceiver errors?

Yes! The LS-SM311G-20I is highly OEM compatible. It complies strictly with MSA standards and works seamlessly with Cisco, Juniper, and other multi-brand switches without triggering any error codes.

Can this module survive in an unventilated outdoor cabinet? Summers here get brutally hot.

Yes, it is a rugged industrial-grade transceiver. It supports extreme operating temperatures ranging from -40°C to 85°C (-40°F to 185°F), making it perfect for harsh outdoor environments, smart city nodes, and base station deployments.

Breadcrumb: Home; Products; Optics Transceivers | SFP Modules; 1/2/4G Transceiver Modules; 1G SFP; 181611

Click to open expanded view

LINK-PP LS-SM311G-20I 1.25G SFP 1310nm 20km Duplex LC DOM SMF Optical Transceiver Module (Industrial)

Name: LINK-PP LS-SM311G-20I 1.25G SFP 1310nm 20km Duplex LC DOM SMF Optical Transceiver Module (Industrial)
Brand: LINK-PP
SKU: 181611
Price: 4.902 USD
Availability: InStock
Rating: 5 (20 reviews)

# 181611

Product: LINK-PP LS-SM311G-20I 1.25G SFP 1310nm 20km Duplex LC DOM SMF Optical Transceiver Module (Industrial)
SKU: 181611
P/N: LS-SM311G-20I
Price: $ 5.7
Stock: 810 in Stock
Sold: 1.4K
Product URL: https://www.l-p.com/products/476093.htm

For Order Over $1000 Get $15.00 Off , Code: Linkpp15

For Order Over $3000 Get $50.00 Off , Code: Linkpp50

For Order Over $5000 Get $100.00 Off , Code: Linkpp100

New Users: $10 Coupon for Orders , Code: linkpp2610

20 Reviews

4 Questions

Request Stock

1.4K Sold

$ 5.7

Free shipping over $600, If you need a more favorable price, please contact us directly.

Qty (pcs) :

Unit Price :

$ 5.7

100

$ 5.415

1000

$ 5.244

3000

$ 5.073

6000

$ 4.902

Manufacture: LINK-PP

P/N: LS-SM311G-20I

Compatible:: Cisco; LINK-PP

Compatible P/N:: LS-SM311G-02C | 2km; LS-SM311G-02I | 2km; LS-SM311G-10C | 10km; LS-SM311G-10I | 10km; LS-SM311G-20C | 20km; LS-SM311G-20I | 20km; LS-SM311G-40AI | 40km; LS-SM311G-40C | 40km; LS-SM311G-40I | 40km; LS-SM551G-40C | 40km; LS-SM551G-40I | 40km; LS-SM551G-60C | 60km; LS-SM551G-60I | 60km; LS-SM551G-80C | 80km; LS-SM551G-80I | 80km; LS-SM551G-A0C | 100km; LS-SM551G-A0I | 100km; LS-SM551G-A2C | 120km; LS-SM551G-A2I | 120km; LS-SM551G-A6C | 160km; LS-SM551G-A6I | 160km

Shipping:

To Be Negotiated

Free Shipping

Can't deliver

to United States via {{now_chooseship?now_chooseship.name:''}}

Estimated delivery time : {{now_chooseship?now_chooseship.datemin:''}}-{{now_chooseship?now_chooseship.datemax:''}} days. See details

5-Year Warranty 30-Day Returns 30-Day Exchange

Stock:

{{parseInt(detail_data.left_num) ? detail_data.left_num +' in Stock' :detail_data.zeroStockOrder==0?'Out of Stock':'Available'}} .

Quantity:

( Min. Order {{detail_data.prodInfo.minimum_ordered_quantity}} )

undeliverable

Total Price:

{{ detail_data.displayed_price.unit_prefix }} {{ detail_data.displayed_price.original_total_price }} ( {{ detail_data.displayed_price.rate_of_discount }}% OFF ) {{detail_data.displayed_price.ex_sell_type}}

Add to wish

Specifications

Specification
Videos
Matching Products
Download
Q&A
Customer Reviews

LINK-PP LS-SM311G-20I 1.25G SFP Specifications

The LINK-PP LS-SM311G-20I is a high-performance, industrial-grade 1.25G SFP optical transceiver designed for dependable gigabit networks. It operates at a 1310nm wavelength over single-mode fiber, achieving transmissions up to 20km via a duplex LC connector. Supporting DOM, this module delivers robust connectivity across extreme temperatures ranging from -40°C to 85°C.

LINK-PP Part Number	LS-SM311G-20I	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	-40 to 85°C	Protocols	SFF-8472 MSA Compliant, IEEE 802.3ah-2004, IEEE 802.3z

Videos

Matching Products

Pictures

ID#

Description

Price

Stock

Add to Cart

Download

Product Drawing

PDF
LS-SM311G-20I.pdf

Questions & Answers
Ask a Question

No data

Q: Does this transceiver require single-mode or multi-mode fiber, and what connector does it use? By D***r on 2026-02-19

A: This specific module requires Single-Mode Fiber (SMF) to achieve its optimal transmission distance of up to 20km at a 1310nm wavelength. It features an industry-standard Duplex LC connector interface. By admin on 2026-02-19
Q: Is this unit fully compliant with standard gigabit ethernet protocols for our legacy setup? By P***s on 2026-02-12

A: Yes, it fully supports IEEE 802.3z and IEEE 802.3ah-2004 standards, alongside SFF-8472 for digital optical monitoring (DOM), ensuring perfect protocol adaptation with both legacy and modern gigabit Ethernet infrastructures. By admin on 2026-02-12
Q: Will these work with my Cisco catalyst switches without throwing any unsupported transceiver errors? By L***s on 2025-10-29

A: Yes! The LS-SM311G-20I is highly OEM compatible. It complies strictly with MSA standards and works seamlessly with Cisco, Juniper, and other multi-brand switches without triggering any error codes. By admin on 2025-10-29
Q: Can this module survive in an unventilated outdoor cabinet? Summers here get brutally hot. By W***z on 2025-10-09

A: Yes, it is a rugged industrial-grade transceiver. It supports extreme operating temperatures ranging from -40°C to 85°C (-40°F to 185°F), making it perfect for harsh outdoor environments, smart city nodes, and base station deployments. By admin on 2025-10-09

Customer Reviews
Write a Review

{{stardata.star}}

{{comment.count}} reviews
5 Stars

{{comment.star5}}%

4 Stars

{{comment.star4}}%

3 Stars

{{comment.star3}}%

2 Stars

{{comment.star2}}%

1 Star

{{comment.star1}}%

All Reviews ({{comment.star_num?comment.star_num:comment.count}})

All Reviews

5 stars only

4 stars only

3 stars only

2 stars only

1 star only
Reviews with Pictures ( {{comment.pic_comment}} )
See All Reviews

No data

M***e

Egypt

Verified Purchase

5 .0

2026-05-21

Solid 1.25G transceiver for single-mode fiber links.

75 Helpful vote Comments

P***s

Viet Nam

Verified Purchase

5 .0

2026-05-12

Deploying these industrial 1.25G SFP modules across outdoor base stations was a breeze. They easily handle extreme temps. DOM reporting is precise, making remote fiber maintenance much simpler for us.

40 Helpful vote Comments

R***e

Poland

Verified Purchase

5 .0

2026-04-20

Flawless 1310nm SFP for our campus network!

52 Helpful vote Comments

B***n

Ireland

Verified Purchase

5 .0

2026-02-14

No issues with IEEE 802.3z protocol adaptation.

23 Helpful vote Comments

S***n

Taiwan, Province of China

Verified Purchase

5 .0

2026-02-12

Perfect for our base station backhaul deployment.

167 Helpful vote Comments

P***h

Argentina

Verified Purchase

5 .0

2025-11-20

Bought a batch for server room deployment. The Duplex LC interfaces are well built.

83 Helpful vote Comments

R***s

Austria

Verified Purchase

5 .0

2025-10-17

Fast delivery, cheap 20km SFP modules.

157 Helpful vote Comments

A***e

Republic of Korea

Verified Purchase

5 .0

2025-09-21

Bulk ordered these for an enterprise LAN backbone upgrade. The Duplex LC connectors mate securely, and SFF-8472 compliance ensures seamless integration. Fantastic gigabit SFP performance at a fraction of brand costs.

74 Helpful vote Comments

W***l

France

Verified Purchase

5 .0

2025-08-16

Using these for our campus fiber network. The 20km transmission on single-mode fiber is perfectly stable. Real-time DOM monitoring is a lifesaver for our server room operations.

134 Helpful vote Comments

R***z

Ecuador

Verified Purchase

5 .0

2025-07-14

Plug and play Duplex LC, zero configuration needed!

194 Helpful vote Comments

E***g

Germany

Verified Purchase

5 .0

2025-05-09

DOM feature works great on Cisco switches.

151 Helpful vote Comments

L***r

Ireland

Verified Purchase

5 .0

2025-05-05

The DDM/DOM monitoring is super accurate. Great OEM compatibility with our diverse network hardware.

46 Helpful vote Comments

E***r

Canada

Verified Purchase

5 .0

2025-04-13

Tested this LINK-PP LS-SM311G-20I transceiver in our core multi-brand switches. OEM compatibility is spot on! The 1310nm laser pushes a solid 20km distance over SMF. Highly recommended for IT ops.

153 Helpful vote Comments

M***z

New Zealand

Verified Purchase

5 .0

2025-04-10

Great industrial SFP for outdoor enclosures!

70 Helpful vote Comments

P***z

Portugal

Verified Purchase

5 .0