1000BASE-BX SFP 20km Transceiver (1490/1310nm) (Side B): BIDI-1.25G-SFP-21-BD
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Same use case, different specifications
1000BASE-BX SFP 20km (1490/1310nm) Side B Overview
Our 1000BASE-BX SFP 20km transceiver delivers extended single-fiber connectivity using 1490/1310nm wavelengths. Supporting 20km transmission over single-mode fiber, this BiDi module provides 15 dB link budget and multi-rate operation from 100 Mbps to 1.25 Gbps. Commercial temperature range 0-70°C with LC/UPC connector. Pair with Side A for bidirectional communication.
- Media Type: Single-Mode Fiber (SMF)
- Fiber Count: BiDi
- Connector: Single LC/UPC
- Maximum Distance: 20 km
- Average Link Budget: 15 dB
- Tx Wavelength: 1490 nm
- Supported Data Rate: 1.063 Gbps - 1.25 Gbps
- DDM/DOM: Supported
- Temperature Range: Standard 0°-70°C
1000BASE-BX SFP 20km (1310/1490nm) Pricing
SKU:BIDI-1.25G-SFP-21-BD
In Stock - Ships Next Business Day1000BASE-BX SFP 20km Transceiver (1490/1310nm) (Side B) Specification
Form Factor | SFP |
Media Type | Single-Mode Fiber (SMF) |
Fiber Count | BiDi |
Connector | Single LC/UPC |
Maximum Distance | 20 km |
Average Link Budget | 15 dB |
TX Wavelength | 1490 nm |
RX Wavelength | 1310 nm |
Supported Data Rate | 1.063 Gbps - 1.25 Gbps |
Supported Ethernet Applications | Gigabit Ethernet (1.25 Gbps) |
Supported Fiber Channel Applications | 1G Fiber Channel (1.0625 Gbps) |
DDM/DOM | Supported |
Tx Wavelength Bandwidth | 40 nm (1470-1510 nm) |
Rx Wavelength Bandwidth | 40 nm (1290-1330 nm) |
Minimum Transmitting Power | -9 dBm |
Maximum Transmitting Power | 3 dBm |
Receiver Sensitivity | -22 dBm |
Receiver Overload | -3 dBm |
Dispersion | 430-500 ps/nm ps/nm |
Transmitter Type | DFB Laser |
Receiver Type | PIN photodiode |
Temperature Range | Standard 0°-70°C |
Power | +3.3V single power supply |
Compliance | CE, Class 1 FDA and IEC60825-1 Laser Safety Compliant, RoHS, INF-8074i, SFP MSA |
1000BASE-BX SFP 20km Transceiver (1490/1310nm) (Side B) Datasheet
v5Complete technical specifications and product details
1000BASE-BX SFP 20km Transceiver (1490/1310nm) (Side B) Description
The BIDI-1.25G-SFP-21-BD is a 1000BASE-BX SFP transceiver for single-fiber Gigabit Ethernet over single-mode fiber, carrying both directions on one strand instead of a duplex pair for metro and campus links.
This module transmits at 1490nm and receives at 1310nm at 1.063 to 1.25 Gbps, so it must pair with a Side A unit (BIDI-1.25G-SFP-21-AD, TX1310/RX1490), never another Side B. It uses a DFB laser and PIN photodiode, unlike Side A's FP laser and narrower dispersion. Average link budget is 15dB over 20km, EDGE's own extended-reach spec for this SKU.
The module is hot-pluggable in a standard SFP cage with a single LC/UPC connector carrying both directions on one strand, following the INF-8074i/SFP MSA electrical interface. DDM/DOM diagnostics (temperature, voltage, TX/RX power, laser bias) run through the EEPROM for host monitoring.
SFP remains the standard pluggable footprint across switches, routers and media converters. This module runs 0 to 70C on a single +3.3V supply, suited to typical rack environments.
Supported protocols are Gigabit Ethernet at 1.25 Gbps and 1G Fiber Channel at 1.0625 Gbps. IEEE 802.3ah defines 1000BASE-BX10 at 10km and 8dB; this SKU's 20km, 15dB figures are EDGE's own extended-reach design, not an IEEE-defined distance. Certifications include CE, RoHS and Class 1 laser safety per FDA and IEC60825-1.
Typical deployments include metro access rings, campus backbones and carrier access nodes, cutting cable count and splice points versus duplex fiber runs. Backed by 15+ years of EdgeOptic compatibility engineering, this module ships next business day from EU stock with a lifetime warranty. For volume pricing, contact our sales team.
Frequently Asked Questions
Why does a BiDi SFP need to be deployed in a matched pair (Side A with Side B)?
BiDi modules use wavelength division to send and receive on a single fiber strand instead of a duplex pair. This Side B module transmits at 1490nm and receives at 1310nm, so it only links up against a Side A unit transmitting at 1310nm and receiving at 1490nm. Two Side B modules facing each other transmit on the same wavelength and receive on the wrong one, so the link never comes up.
What is the difference between 1000BASE-BX10-D and 1000BASE-BX10-U?
The -D designation transmits at 1490nm and receives at 1310nm, which is this module, BIDI-1.25G-SFP-21-BD. The -U designation transmits at 1310nm and receives at 1490nm, the Side A counterpart, BIDI-1.25G-SFP-21-AD. The two must be installed at opposite ends of the same fiber strand.
Can a BiDi SFP plug into a standard duplex SFP port?
Yes. The SFP host cage and electrical interface follow the standard SFP MSA and INF-8074i specification regardless of BiDi or duplex optics. The difference is the single LC/UPC connector on the BiDi module and the requirement to pair it with an opposite-wavelength partner module, not the host port itself.
How is this 1490nm/1310nm 20km module different from a 1550nm/1310nm 20km BiDi module?
Both are 20km single-fiber BiDi modules, but the wavelength plans differ: this module transmits at 1490nm and receives at 1310nm, while a 1550nm/1310nm module transmits at 1550nm. The two wavelength plans are not interoperable with each other, so every module on a given link, at both ends, must share the same wavelength plan.