Cisco GLC-BX-20U Compatible 1G SFP Transceiver Module
This Cisco GLC-BX-20U compatible transceiver provides 1G connectivity in a hot-swappable SFP package. Its optical design operates at 1310nm-TX/1550nm-RX for up to 20km, using Simplex LC/UPC. Complete parameters and related OEM references help field technicians install, maintain and identify the exact compatible module.
OEM Part Number: GLC-BX-20UHT Part Number: SFP-1G35-BX20
Product Highlights
- Compatible alternative to Cisco GLC-BX-20U
- 1G connectivity at 1.25Gbps
- Optical wavelength: 1310nm-TX/1550nm-RX
- Specified reach: 20km
- Simplex LC/UPC / SMF interface
- Digital diagnostic monitoring: Supported
- Operating temperature: 0 to 70°C (32 to 158°F)
Specifications
| Cisco Compatible | GLC-BX-20U |
|---|---|
| Manufacturer | HT |
| HT Part Number | SFP-1G35-BX20 |
| Form Factor | SFP |
| Max. Data Rate | 1.25Gbps |
| Wavelength | 1310nm-TX/1550nm-RX |
| Max. Cable Distance | 20km |
| Connector | Simplex LC/UPC |
| Media | SMF |
| Transmitter Type | DFB BiDi |
| Receiver Type | PIN |
| TX Power | -9~-3dBm |
| Minimum Receiver Power | <-20dBm |
| Power Budget | 11dB |
| Receiver Overload | -3dBm |
| Max. Power Consumption | 1W |
| Extinction Ratio | 9dB |
| DDM/DOM | Supported |
| Commercial Temperature Range | 0 to 70°C (32 to 158°F) |
| Bit Error Ratio (BER) | 1E-12 |
| Protocols | Fast Ethernet, Gigabit Fibre Channel, MSA Compliant |
Field Installation and Maintenance
Inspect the connector and patch lead before installation, then support the fiber without pulling on the module housing. Release the latch properly during maintenance and keep dust protection on unused interfaces. If a module is removed for later use, retain its part-number label and record its original port. For this model, the principal parameters are data rate 1.25Gbps, wavelength 1310nm-TX/1550nm-RX, rated reach 20km.
Applications and Optical Link Design
This BiDi interface is useful where only one fiber strand is available between two sites or racks. It must be paired with the complementary wavelength direction: one end transmits on the wavelength that the other end receives. Verify the paired part number, connector polish and fiber plant before installation, and measure link loss against the specified optical budget.
Before deployment, check the host port type, supported data rate and firmware requirements. The 1G interface configuration must match the remote equipment; sharing a SFP housing alone does not make two transceiver types interoperable.
This single-fiber interface must be paired with the complementary wavelength direction. One end transmits on the wavelength the other receives. Verify connector polish and measure loss over the 20km design range before service.
Optical Acceptance, Diagnostics and Handling
For this model, the specified transmit-power range is -9~-3dBm; the stated optical power budget is 11dB. A sound acceptance record includes link state, diagnostic temperature, supply voltage and transmit or receive levels where the host exposes them. Compare the readings with the stated ranges rather than treating any received light as proof of adequate margin. Persistent alarms or borderline values should trigger an end-face and complete-channel inspection. Diagnostic monitoring is listed as Supported. Before every insertion, keep dust caps in place until the patch lead is ready, avoid touching the optical end face and use an appropriate inspection and cleaning procedure. Do not look into an active optical interface.
Quality Assurance and Packaging
Quality control covers the optical or electrical interface, host identification and operating link. The verified unit is then individually protected and cartoned. Customer references, rack groups and project packing lists can be added for volume orders.
Cisco Compatibility and Factory Testing
Factory verification starts with the expected GLC-BX-20U identity and finishes with an operating host link. EEPROM data, diagnostic visibility and the stated optical parameters are assessed together. Equipment model, hardware revision and software release can be reviewed before dispatch where platform behavior is uncertain.
Frequently Asked Questions
Is this an original Cisco transceiver?
No. It is an HT-manufactured compatible alternative for equipment that specifies GLC-BX-20U, not an original Cisco-branded module.
Which fiber and connector are required?
Use Simplex LC/UPC with SMF. The specified maximum reach is 20km, subject to fiber quality and total link loss.
Can it be mixed with another wavelength or reach version?
Only when the two ends share the same optical standard, wavelength plan and supported data rate. Check the exact part numbers and link budget rather than relying only on the module form factor.
Ordering Information
Quote HT part number SFP-1G35-BX20 together with OEM reference GLC-BX-20U and quantity. Add the host model and software release when pre-order verification is required. Neutral labels, customer packaging and project-specific compatibility review are available on request.
Shipping and Lead Time
Standard configurations normally ship within one to three working days, with production lead times confirmed for larger quantities. International courier, air freight and sea freight are available; customer courier accounts and nominated forwarders are accepted.
