QSFP28 vs. QSFP+: Compatibility, Use Cases, and Backwards Compatibility
Is QSFP28 Compatible with QSFP+?
In the evolving world of data centers and high-speed networking, compatibility between different generations of transceivers is a critical consideration. QSFP28 and QSFP+ are two such transceiver types commonly used for 100G and 40G Ethernet networks, respectively. This article explores QSFP+ and QSFP28 compatibility and whether QSFP+ modules can be used in QSFP28 ports and vice versa.
Understanding QSFP28 and QSFP+
QSFP28:
- •Designed for 100 Gigabit Ethernet (100GbE) networks.
- •Provides four 25Gbps lanes, totaling 100Gbps.
- •Used for high-density, high-speed network connections.
QSFP+:
- •Designed for 40 Gigabit Ethernet (40GbE) networks.
- •Provides four 10Gbps lanes, totaling 40Gbps.
- •Widely used for moderate-speed data center and enterprise network applications.
Can QSFP+ Be Plugged into QSFP28 Ports and Vice Versa?
QSFP+ in QSFP28 Ports:
- •Backward Compatibility: QSFP28 ports are generally backward compatible with QSFP+ modules. This means you can plug a QSFP+ module into a QSFP28 port, and it will function properly. The port will automatically downgrade to support 40Gbps transmission, utilizing the QSFP+ module’s capability.
- •Use Case: This backward compatibility is useful for network upgrades, allowing for a phased approach where existing QSFP+ modules can still be utilized while new QSFP28 infrastructure is deployed.
QSFP28 in QSFP+ Ports:
- •Forward Compatibility: QSFP+ ports are not forward compatible with QSFP28 modules. A QSFP28 module cannot be used in a QSFP+ port because the QSFP+ port lacks the necessary hardware and signaling capabilities to support the higher data rates and specifications of QSFP28.
- •Use Case Limitation: Therefore, if you need to upgrade a QSFP+ network to 100Gbps, replacing both the transceivers and the switch or router ports to QSFP28 is necessary.
Conclusion
In summary, QSFP28 ports offer backward compatibility with QSFP+ modules, allowing for flexible and cost-effective network upgrades. However, QSFP28 modules cannot be used in QSFP+ ports. Understanding these compatibility dynamics helps in planning and executing network infrastructure upgrades, ensuring seamless transitions and optimal performance in high-speed networking environments.
Our Related Modules
| Description | EDGE SKU | Details |
|---|---|---|
| 40G QSFP+ Multimode | 40G-QSFP-150 | 40G QSFP+ Module (Tx/Rx 850/850nm, up to 44.8 Gbps, Max. 150m over MMF (OM4), 1.9 dB, Temp. 0-70C, MTP/MPO Connector) |
| 40G QSFP+ Singlemode | 40G-QSFP-10 | Double Fiber 40G QSFP+ Module (Tx/Rx 4 CWDM lines:1271,1291,1311,1331, up to 44.8 Gbps, Max. 10km over SMF, 9.7 dB, Temp. 0-70C, LC Connector) |
| 100G QSFP28 Multimode | 100G-QSFP28-100 | 100GBASE-SR4 QSFP28 Module (Tx/Rx 850/850nm, 103.125 Gbps, Max. 100m (OM4) over MMF, 1.9 dB, Temp. 0-70C, MTP/MPO Connector) |
| 100G QSFP28 Singlemode | 100G-QSFP28-10 | Double Fiber 100GBASE-LR4 QSFP28 Module (Tx/Rx 4 LAN WDM lines:1295.56, 1300.05, 1304.58, 1309.14, 103.125 Gbps, Max. 10km over SMF, 6.3 dB, Temp. 0-70C, LC Connector) |
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Products and categories featured in this article.
40G QSFP+ Optical Transceiver Modules
Our comprehensive range of 40G QSFP+ optical transceiver modules delivers reliable high-speed connectivity for modern data center and enterprise networks. From short-reach multimode SR4 solutions for data center interconnects to long-haul ER4 transceivers reaching 40km for metro applications, our QSFP+ portfolio covers all distance requirements. We offer advanced technologies including CWDM for simplified cabling, BiDi for dual-fiber operation, PSM4 for parallel single-mode transmission, and SWDM4 for extended multimode reach. All modules are MSA-compliant, hot-pluggable, and rigorously tested for compatibility with major network equipment vendors.
100G QSFP28 Optical Transceivers
Welcome to our collection of 100G QSFP28 transceivers! The 100G QSFP28 optical transceiver are designed according to SFF-8665 standard which specifies QSFP+ 28 Gb/s 4X Pluggable Transceiver Solution (QSFP28) for 100 Gigabit Ethernet. 100G QSFP28 transceivers have the exact same footprint as it’s predecessor 40G QSFP+, but has variations where modules can have NRZ modulation (100G SR4, LR4, ER4, ZR4…) and there are some newer generation 100G QSFP28 Single Lambda modules (100G LR1, FR1, DR1) which use PAM4 modulation (more on PAM4 vs NRZ). We offer a wide range of optical modules tailored to diverse networking environments to cover all industry needs. Some of our most popular 100G modules are the 100G QSFP28 SR4 (PN: 100G-QSFP28-100) designed for short range (below 150m) Multi-Mode Fiber connections, 100G QSFP28 LR4 (PN: 100G-QSFP28-10) designed for long range (up to 10km) Single-Mode Fiber connections and 100G QSFP28 ER4 (PN:100G-QSFP28-40) designed for long range (up to 40km) Single-Mode Fiber connections. To help engineers find the correct units for their setup, we’ve sorted our 100G QSFP28 transceivers in the categories below based on their type and functionality. Not only do we offer a wide range of MSA compatible modules, but all of them can be re-programmed to be compatible with a wide range of devices. From industry-standard solutions to specialized modules, find the perfect fit for your network requirements.