# TP-Link ISM321A-20 Industrial SFP Fiber Optic Transceiver Module, 1250 Mbit/s, WDM, 20km

**URL:** https://aio.lv/en/product--tp-link-ism321a-20--11545912
**Data updated:** 2026-06-05 12:24 (EEST)
**Category:** Network Switches
**Manufacturer:** TP-LINK
**Manufacturer code:** ISM321A-20
**EAN:** 1210002601993
**Warranty:** 5 Years
**Availability:** Available for order
**Price:** 15.99 €
**Prices and availability valid until:** 2026-07-11 23:59
**Price without VAT (21%):** 13.21 EUR
**Can be purchased by legal entities:** Yes (invoice)
**Buy:** https://aio.lv/en/product--tp-link-ism321a-20--11545912

## Delivery options

| Delivery method | Delivery time | Cost |
|---|---|---|
| Office pickup (2b. Kengaraga str., Riga, Latvia, LV-1063) | Wednesday | free |
| Pickup points | 22.06.2026 | 1.99 EUR |
| Courier delivery to door | 22.06.2026 | 4.99 EUR |

## Summary description

The TP-Link ISM321A-20 is an industrial-grade SFP fiber optic transceiver module designed for high-speed network connectivity. It supports a maximum data transfer rate of 1250 Mbit/s and utilizes WDM technology for bidirectional communication over a single fiber strand up to 20km. Compliant with IEEE 802.3z standards, this module is built for reliable performance in demanding environments with an operating temperature range of -40°C to 85°C.

## Long description

The TP-Link ISM321A-20 is an industrial-grade SFP fiber optic transceiver module engineered for high-performance network connectivity in challenging environments. It supports data transfer rates of up to 1250 Mbit/s and utilizes WDM technology to enable bidirectional communication over a single fiber strand, effectively doubling the capacity of existing fiber infrastructure. Designed for reliability, this module ensures stable operation across a wide temperature range, making it an ideal choice for industrial networking applications.
Advantages
This transceiver module offers exceptional durability, featuring an industrial operating temperature range from -40°C to 85°C, which allows it to function reliably in extreme conditions where standard commercial equipment might fail. The integration of WDM technology simplifies cabling by requiring only a single fiber strand for bidirectional data transmission, reducing installation complexity and costs. Furthermore, the support for DDM (Digital Diagnostic Monitoring) provides real-time insights into the module's performance, enabling proactive maintenance and troubleshooting to ensure maximum network uptime.
Suitable for
Industrial automation and control systems
Long-distance network backhaul in harsh environments
Expanding network capacity over existing single-mode fiber
Outdoor surveillance and security infrastructure
This module may not be suitable for short-range indoor office environments where standard commercial-grade transceivers are sufficient and more cost-effective. Additionally, it is not compatible with multi-mode fiber optic cabling, as it is specifically designed for single-mode fiber applications.
Key specifications
Data transfer rate: 1250 Mbit/s
Interface: SFP with LC connector
Technology: WDM (Bi-Directional)
Fiber type: Single-mode
Maximum distance: 20 km
Operating temperature: -40°C to 85°C
Input voltage: 3.3 V
Standards: IEEE 802.3z
To use the TP-Link ISM321A-20, simply insert the module into a compatible SFP slot on your network switch or industrial gateway. The device is hot-swappable, meaning it can be installed or replaced without powering down the host equipment. Once inserted, connect the appropriate single-mode fiber optic cable to the LC port. The system should automatically detect the module, though you may need to configure the port settings in your network management interface to match the link speed and duplex requirements.
What to consider before purchase
Ensure your network switch or device supports SFP modules with 1.25 Gbps speeds.
Verify that your fiber optic infrastructure uses single-mode cabling.
Confirm that the WDM wavelength requirements match your existing network setup.
Check the physical space constraints of your equipment to ensure the module fits correctly.
Usage recommendations
For optimal performance and longevity, ensure that the fiber optic connectors are clean and free of dust before insertion. Avoid bending the fiber optic cable beyond its minimum bend radius to prevent signal loss or physical damage to the glass core.

## Specifications

| Feature | Value |
|---|---|
| Interface type | SFP |
| Maximum operating temperature | 85 °C |
| Hot-swap | Yes |
| Maximum transfer distance | 20000 m |
| Fiber cable diameters supported (core/cladding) | 9/125 |
| SFP transceiver type | Fiber optic |
| Minimum operating temperature | -40 °C |
| Single-mode fiber (SMF) supported | Yes |

### Operational conditions

| Feature | Value |
|---|---|
| Operating relative humidity (H-H) | 5 - 85 |
| Storage temperature (T-T) | -40 - 85 |
| Storage relative humidity (H-H) | 5 - 85 |

### Performance

| Feature | Value |
|---|---|
| Maximum data transfer rate | 1250 Mbit/s |

### Certificates

| Feature | Value |
|---|---|
| Certification | FCC, CE |

### Power

| Feature | Value |
|---|---|
| Input voltage | 3.3 |

### Weight & dimensions

| Feature | Value |
|---|---|
| Height | 10.97 mm |
| Width | 56.4 mm |
| Depth | 13.4 mm |

### Design

| Feature | Value |
|---|---|
| Product colour | Grey |

### Network

| Feature | Value |
|---|---|
| Networking standards | IEEE 802.3z |

### Other features

| Feature | Value |
|---|---|
| Ethernet interface type | 1.25 Gigabit Ethernet |

### Ports & interfaces

| Feature | Value |
|---|---|
| Fiber optic connector | LC (UPC) |

## FAQ

### How much does the TP-Link ISM321A-20 SFP Fiber Optic Transceiver Module cost, and is it available for purchase?

The price is 15.99 € (valid at the time of publication and already includes all taxes). The item is available for order — 13 pcs. are in stock, and you can place your purchase right now with delivery across Latvia and Europe or choose pickup at the Riga collection point. We offer favorable purchase terms, including the option to split the payment into convenient monthly installments. Availability and price are updated in real time, so we recommend placing your order in advance.

### If I order this product today, when will I receive my order?

If you place your order today, delivery will be as fast and convenient as possible. You will be able to pick up your order on Wednesday at the Riga pickup point or choose delivery across Latvia and Europe. We carefully inspect every purchase and pack it securely for safe transportation.

### What payment options are available?

AiO.lv offers several payment methods: Bank transfer, Bank cards on-line, Apple Pay, Google Pay. All transactions are 100% secure and encrypted.

### Can this product be purchased for a company (with VAT)?

Yes. AiO.lv works with legal entities in Latvia and across Europe. The product price already includes VAT. For certain product categories, as well as for companies from other EU countries with a valid VAT number, a 0% VAT rate may apply. We issue the invoice immediately after the order is placed, support electronic BIS invoices, and automatically generate all necessary accounting documents. You can complete the purchase for a company online — simply select the company profile and choose bank transfer as the payment method during checkout.

### What is the warranty period?

All TP-LINK products come with an official 2 Years warranty. It covers all manufacturing defects and malfunctions that may occur during use. The warranty is valid at all authorized TP-LINK service centers and through AiO.lv

### Can the product be returned after purchase?

Yes, you can return the product within 14 days of purchase if you bought it as a consumer (not a legal entity). Returns are possible without giving any reason — the main condition is that the product retains its original appearance and full set of accessories. We will make the process as simple and convenient as possible: just contact our customer support team, and we will help you arrange the return.

### Where should I contact for warranty service?

For warranty-related questions you can contact the AiO.lv (SIA VSPRO) customer support team. More information about warranty service: https://aio.lv/en/warranty

### How can I tell if this product suits my needs?

When making a choice, we recommend paying attention to the key features: product colour, networking standards, compatibility with your devices or usage conditions, material quality, functionality, and warranty terms. These characteristics will help you determine how well the model meets your needs.

### Where can I download the instructions for TP-Link ISM321A-20 SFP Fiber Optic Transceiver Module?

You can download the instructions in PDF format from the “Instructions” section on the product description page. The file contains complete information about installation, setup, and usage.

## Image

https://aio.lv/img/cache/product/11545912/68835219_large.webp