Extreme 40GB-ESR4-QSFP Compatible 40G QSFP+ ESR4 Transceiver Module

The 40GB-ESR4-QSFP compatible module serves equipment requiring a 40G QSFP+ interface with 850nm optics and a 400m on OM4 rating. Connection is through MTP/MPO-12 Male. Product data, application guidance and factory verification are presented together to support field technicians install, maintain and identify the exact compatible module.
OEM Part Number: 40GB-ESR4-QSFPHT Part Number: QSFP-CSR4-40G
Product Highlights
- Compatible alternative to Extreme 40GB-ESR4-QSFP
- 40G connectivity at 42Gbps (4x 10.5Gbps)
- Optical wavelength: 850nm
- Specified reach: 400m on OM4
- MTP/MPO-12 Male / MMF interface
- Operating temperature: 0 to 70°C (32 to 158°F)
- Factory compatibility verification and optical performance testing before shipment
Specifications
| Extreme Networks Compatible | 40GB-ESR4-QSFP |
|---|---|
| Manufacturer | HT |
| HT Part Number | QSFP-CSR4-40G |
| Form Factor | QSFP+ |
| Max. Data Rate | 42Gbps (4x 10.5Gbps) |
| Wavelength | 850nm |
| Max. Transmission Distance | 400m@OM4 |
| Connector | MTP/MPO-12 Male |
| Media | MMF |
| Transimitter Type | VCSEL 850nm |
| Receiver Type | PIN |
| TX Power | -7.5~0dBm |
| Receiver Sensitivity | <-9.9dBm |
| Power Budget | 2.4dB |
| Receiver Overload | 2.4dBm |
| Max. Power Consumption | ≤1.5W |
| Extinction Ratio | >3dB |
| Host FEC | Supported |
| Bit Error Ratio (BER) | 1E-12 |
| Operating Temperature | 0 to 70°C (32 to 158°F) |
| Protocols | 40G Ethernet, SATA/SAS3, IEEE 802.3ba, 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 42Gbps (4x 10.5Gbps), wavelength 850nm, rated reach 400m on OM4.
Applications and Optical Link Design
Typical deployments include switch-to-switch, switch-to-server and aggregation links inside a data hall or between adjacent equipment rooms. The MTP/MPO-12 Male interface connects to the specified multimode cabling, and the stated reach depends on fiber grade and link loss. Keep this interface on the matching multimode optical standard rather than connecting it directly to a single-mode wavelength or reach variant.
Before deployment, check the host port type, supported data rate and firmware requirements. The 40G interface configuration must match the remote equipment; sharing a QSFP+ housing alone does not make two transceiver types interoperable.
For this multimode module, confirm fiber grade, modal bandwidth and total loss before commissioning. The 400m on OM4 figure applies only under suitable cabling conditions. Inspect every MTP/MPO-12 Male mating point and match the remote optical standard.
Optical Acceptance, Diagnostics and Handling
For this model, the specified transmit-power range is -7.5~0dBm; receiver sensitivity is <-9.9dBm; the stated optical power budget is 2.4dB. 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. 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.
Extreme Compatibility and Factory Testing
Compatibility testing for 40GB-ESR4-QSFP combines identification with a live link and available transmit, receive and alarm information. Connector condition is inspected separately. Equipment model, hardware revision and software release can be reviewed before dispatch where platform behavior is uncertain.
Frequently Asked Questions
Is this an original Extreme transceiver?
No. It is an HT-manufactured compatible alternative for equipment that specifies 40GB-ESR4-QSFP, not an original Extreme-branded module.
Which fiber and connector are required?
Use MTP/MPO-12 Male with MMF. The specified maximum reach is 400m on OM4, 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 QSFP-CSR4-40G together with OEM reference 40GB-ESR4-QSFP 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.
