TP-LINK TL-SM321B-2 1000Base-BX WDM Bi-Directional SFP Module (1310nm TX / 1550nm RX)
SKU: SM321BNetworking › Network Accessories
Please enquire before ordering
The distributor has not yet confirmed the latest price and availability (last checked Sep 11, 2026)
092-251-4017Awaiting stock confirmation2 years manufacturer's warranty
GenuineFree delivery from ฿5,000Tax invoice
Bi-Directional SFP module for long-range network connectivity over fiber optic cable, supporting data transmission up to 20 kilometers, designed to work as a pair with TL-SM321A
Key features
- Supports maximum data transmission distance of up to 20 kilometers
- Uses a single Single-Mode fiber optic cable
- Simultaneous transmission and reception using different wavelengths (WDM)
- Supports DDM for real-time status monitoring
- Works as a pair with TL-SM321A
Product description
TP-LINK TL-SM321B-2 module is designed to work with the TL-SM321A module to enable Gigabit network communication up to 20 kilometers using a single Single-Mode fiber optic cable for simultaneous transmission and reception via different wavelengths (1310 nm for transmission and 1550 nm for reception), significantly reducing fiber cable installation costs. This module supports IEEE 802.3z standard and is compatible with all TP-Link network devices supporting SFP-MSA, featuring DDM (Digital Diagnostic Monitoring) to monitor real-time operational status such as signal transmit/receive rate, voltage, and internal module temperature.
More features
- Supports SFP-MSA and Hot Swappable
- Operates in temperatures from 0–70 °C
- Compact size, portable, and easy to install
Pros and limitations
Pros
- Transmits data up to 20 kilometers using a single fiber optic cable
- Supports DDM for real-time operational status monitoring
- Efficiently works as a pair with the TL-SM321A module
- Compact size, easy to install, and supports Hot Swap
- Supports SFP-MSA standard, compatible with a wide range of devices
Limitations
- Must be used with TL-SM321A module only to operate at full performance.
- Does not support long-distance data transmission beyond 20 kilometers.
Who it is for
Ideal for organizations needing to extend long-distance networks between buildings, data centers, or workstations using a single fiber optic cable to reduce cabling costs and improve data transmission efficiency.
Connectivity
Fiber Optic
Specifications (30)
- Brand
- TP-LINK
- Model
- TL-SM321B-2
- Weight
- Approx. 30 g
- Standard
- IEEE 802.3z
- Data Rate
- 1.25 Gbps
- Port Type
- LC Simplex
- Cable Type
- Single-Mode Fiber
- Fiber Type
- 9/125 μm Single-Mode
- Application
- Gigabit Ethernet, Media Converter, Network Extension
- DDM Support
- Yes
- Duplex Mode
- Bi-Directional WDM
- Form Factor
- Small Form Pluggable (SFP)
- Power Supply
- 3.3 V
- Product Type
- SFP Module
- Compatibility
- Works with TL-SM321A-2 as a pair
- Hot Swappable
- Yes
- Wavelength RX
- 1550 nm
- Wavelength TX
- 1310 nm
- Max Cable Length
- 20 KM
- Module Interface
- LC Simplex Connector
- Storage Humidity
- 5–90% RH, Non-Condensing
- Safety & Emission
- FCC, CE
- Transmission Mode
- WDM Bi-Directional
- Operating Humidity
- 10–90% RH, Non-Condensing
- SFP-MSA Compliance
- Yes
- Storage Temperature
- -40–85 °C (-40–185 °F)
- Operating Temperature
- 0–70 °C (32–158 °F)
- Dimensions (W x D x H)
- 2.2 × 0.6 × 0.5 in (55.4 × 14.6 × 12.9 mm)
- Standards and Protocols
- IEEE 802.3z, TCP/IP
- Digital Diagnostic Monitoring
- Yes (SFF-8472 compatible)
Datasheets and manuals straight from the manufacturer — select a document to open or download it.
12 questions
Frequently asked questions about this product
Compiled from manufacturer information
Which models is the TL-SM321B-2 module compatible with?
This module must be used with the TL-SM321A-2 module to establish Full-Duplex communication over a single fiber optic cable. It is compatible with TP-Link network devices supporting SFP-MSA, such as switches, media converters, and routers.
What type of fiber optic cable can be used?
Supports only a single 9/125 μm Single-Mode fiber optic cable, capable of transmitting data up to 20 kilometers as per the 1000Base-BX standard
Does it have a feature to monitor operational status?
Yes, this module supports Digital Diagnostic Monitoring (DDM), allowing real-time monitoring of values such as signal transmit/receive rates, voltage, and internal temperature via the SFF-8472 protocol.
Can it be used with general switches?
Only compatible with switches or devices that support SFP ports and have WDM Bi-Directional module support configured. Compatibility should be verified with the switch model before use.
What is the maximum transmission distance?
This module supports data transmission up to 20 kilometers, requiring a 9/125 μm Single-Mode fiber optic cable and must be used with the TL-SM321A-2 module
Can the module be replaced while the system is running?
Yes, this module supports Hot Swap, allowing replacement while the system is running without shutting down, enhancing network maintenance flexibility.
Is it compatible with the Omada system?
Yes, the TL-SM321B-2 module supports the Omada system and can be managed through the Omada Controller app, working with any Omada device that supports SFP.
Is it in stock?
We are confirming the latest stock and price of the TP-LINK TL-SM321B-2 1000Base-BX WDM Bi-Directional SFP Module (1310nm TX / 1550nm RX) with the distributor. Please contact us before ordering at 092-251-4017 or sales@gist.co.th.
How much does it cost?
The distributor has not yet confirmed the latest price and availability. Please contact us before ordering at 092-251-4017 or sales@gist.co.th.
How long is the warranty?
Warranty period: 2-year warranty. (manufacturer's terms). To make a warranty claim, call 092-251-4017 or 065-523-5262, or email sales@gist.co.th (Mon–Fri 9:00–18:00), then send the product with your order number to our head office, or bring it to the head office in person.
How long does delivery take?
Orders placed before 12:00 on a business day are delivered within 1–3 business days (Bangkok and vicinity) or 2–5 business days (other provinces). Free delivery on orders of ฿5,000 or more (a ฿150 delivery fee applies below this amount).
Is it genuine?
Genuine products sourced from distributors in Thailand, covered by the manufacturer's warranty. Full tax invoices are available.
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Genuine products
Sourced from distributors in Thailand and covered by the manufacturer's warranty
Warranty period
2-year warranty.
Covered by the manufacturer's warranty; you can make claims through GIST
Claims through GIST
Ship the product to our head office or bring it in person
Warranty conditions
- A receipt or other proof of purchase is required
- The product must not have been modified or altered
- Damage caused by misuse is not covered by the warranty
- To make a warranty claim, call 092-251-4017 or 065-523-5262, or email sales@gist.co.th (Mon–Fri 9:00–18:00), then send the product with your order number to our head office, or bring it to the head office in person.Head office: 554 Sky Nine Center, Floor 12A, Room 554/62, Asok-Din Daeng Road, Din Daeng Subdistrict, Din Daeng District, Bangkok 10400
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