TP-LINK TL-SM321A-2 1000Base-BX WDM Bi-Directional SFP Module (LC Simplex) 1.25 Gbps
SKU: SM321A-2Networking › Network Accessories
Please enquire before ordering
The distributor has not yet confirmed the latest price and availability (last checked Aug 11, 2026)
092-251-4017Awaiting stock confirmation1 year manufacturer's warranty
GenuineFree delivery from ฿5,000Tax invoice
TP-LINK TL-SM321A-2 optical module supports bidirectional communication over single-mode fiber with a maximum distance of 2 kilometers, designed for use with SFP-compatible switches or network devices to enhance long-distance connectivity
Key features
- Supports up to 2 km transmission over single-mode fiber
- Uses different wavelengths TX: 1550 nm / RX: 1310 nm on a single LC port
- Supports DDM (Digital Diagnostic Monitoring) for real-time status monitoring
- Must be used with TL-SM321B-2 to enable full-duplex operation
- Supports hot swapping
Product description
TP-LINK TL-SM321A-2 optical module is a WDM fiber media converter that supports the 1000Base-BX standard, capable of transmitting data up to 1.25 Gbps over a single-mode fiber (Single-Mode Fiber) with a maximum reach of 2 kilometers, using different wavelengths for transmission (TX: 1550 nm) and reception (RX: 1310 nm) on a single LC Simplex port, effectively saving fiber cables. This module must be used with the TL-SM321B-2 to establish a stable full-duplex connection. It supports real-time module diagnostics via the DDM (Digital Diagnostic Monitoring) feature compliant with the SFF-8472 standard, enabling continuous monitoring of parameters such as temperature, current, and optical power. The module supports hot swapping and complies with the SFP-MSA standard for compatibility with multiple network devices.
More features
- Compliant with SFP-MSA and IEEE 802.3z standards
- Designed for use in general network environments
- Supports operating temperature range from 0–70 °C
Pros and limitations
Pros
- Enables long-distance communication up to 2 kilometers using a single fiber
- Uses WDM technology to efficiently save fiber cables
- Supports DDM for real-time module status monitoring
- Designed to work immediately with its counterpart model
- Supports hot swapping without shutting down the system
Limitations
- Must be used with another module (TL-SM321B-2) to operate at full performance
- Compact size may increase risk of loss or damage if not stored carefully
Who it is for
Ideal for users who need to extend long-distance networks in office or data center environments, especially when connecting switches or servers via single-mode fiber up to 2 kilometers at Gigabit speed
Specifications (18)
- DDM
- Yes
- Cable
- Single-Mode Fiber
- SFP-MSA
- Yes
- Data Rate
- 1.25 Gbps
- Port Type
- LC Simplex
- Fiber Type
- 9/125 μm Single-Mode
- Wave Length
- TX: 1550 nm, RX: 1310 nm
- Power Supply
- 3.3 V
- Hot Swappable
- Yes
- Max Cable Length
- 2 KM
- Storage Humidity
- 5–90% RH, Non-Condensing
- Safety & Emission
- FCC, CE
- Compatibility Pair
- TL-SM321B-2
- Dimensions (W*D*H)
- 2.2*0.6*0.5 in (55.4*14.6*12.9 mm)
- Operating Humidity
- 10–90% RH, Non-Condensing
- Storage Temperature
- -40–85 °C (-40–185 °F)
- Operating Temperature
- 0–70 °C (32–158 °F)
- Standards and Protocols
- IEEE 802.3z, TCP/IP
Datasheets and manuals straight from the manufacturer — select a document to open or download it.
11 questions
Frequently asked questions about this product
Compiled from manufacturer information
Can the TL-SM321A-2 module be used with general switches?
Yes, it works as long as the switch supports SFP ports and WDM modules, especially models compliant with SFP-MSA and IEEE 802.3z
How should TL-SM321A-2 be connected with TL-SM321B-2?
Connect the same fiber cable from the SFP ports of both switches. The TL-SM321A-2 and TL-SM321B-2 modules work together using different wavelengths (TX: 1550 nm / RX: 1310 nm) to enable full-duplex communication over a single fiber
Does this module support status monitoring?
Yes, it supports the DDM (Digital Diagnostic Monitoring) feature, which displays real-time values such as temperature, current, and optical power through network management software
How far can it transmit data?
This module supports data transmission up to a maximum distance of 2 kilometers, requiring a 9/125 μm single-mode fiber (Single-Mode Fiber)
Do I need to buy a pair to use it?
Yes, the TL-SM321A-2 module must be used with the TL-SM321B-2 to enable bidirectional communication over a single fiber. It cannot operate alone
Does it support hot swapping?
Yes, this module supports hot swapping, allowing it to be removed or installed without shutting down the device or interrupting the system
Is it in stock?
We are confirming the latest stock and price of the TP-LINK TL-SM321A-2 1000Base-BX WDM Bi-Directional SFP Module (LC Simplex) 1.25 Gbps 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: 1 year (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
1 year
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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