An Introduction to Cisco 40GE QSFP+ Transceiver

QSFP+ (quad small form-factor pluggable plus) is a compact, hot-pluggable transceiver used for network servers, interface cards or switches. Compared with SFP, QSFP+ transceiver increases the port-density of 3-4 times and integrates 4 independent 10 gigabit per second data lanes in each direction to provide 40Gbps bandwidth. A variety of Cisco QSFP+ transceivers are introduced into the market, such as Cisco QSFP-40G-LR4, Cisco QSFP-40G-SR4, Cisco QSFP-40G-CSR4, Cisco QSFP 40G BiDi, Cisco QSFP-40G-PLR4, etc. This post mainly introduces four Cisco 40GE QSFP+ transceivers, including: Cisco QSFP-40G-LR4, Cisco QSFP-40G-SR4, Cisco QSFP-40G-CSR4, Cisco QSFP 40G BiDi.

Cisco QSFP-40G-LR4

The Cisco QSFP-40G-LR4 40GBASE-SR4 QSFP+ transceiver supports link lengths of up to 10km over a standard pair of G.652 single-mode fiber with duplex LC connectors. 40 Gigabit Ethernet signal is carried over four wavelengths. Multiplexing and demultiplexing of the four wavelengths are managed within the device. This Cisco QSFP+ transceiver supports 40 Gigabit Ethernet and OTU3. In addition, this transceiver has diagnostic features, providing real-time monitoring of transmitted optical power, received optical power, laser bias current, etc. It is optimized to 40 Gigabit Ethernet switches and routers.

Cisco QSFP-40G-SR4

The Cisco QSFP-40G-SR4 40GBASE-SR4 QSFP+ transceiver can be used in 4x10G mode for distances of up to 100m on OM3 and 150 m on OM4 fibers. It primarily enables high-bandwidth 40G optical links over 12-fiber parallel fiber terminated with MPO/MTP multifiber connectors. Generally the 4x10G connectivity is obtained by using an external 12-fiber parallel to 2-fiber duplex breakout cable, which connects the 40GBASE-SR4 transceiver module to four 10GBASE-SR optical interfaces. This worry-free 4x10G mode operation is enabled by the optimization of the transmit and receive optical characteristics of the Cisco 40GBASE-SR4 to prevent receiver overload or unnecessary triggering of alarm thresholds on the 10GBASE-SR receiver. This transceiver is optimized to guarantee interoperability with any IEEE 40GBASE-SR4 and 10GBASE-SR.

Cisco QSFP-40G-CSR4

The Cisco QSFP-40G-CSR4 40GBASE-CSR4 QSFP+ transceiver is an extension product from Cisco QSFP-40G-SR4 40GBASE-SR4 QSFP+ transceiver. It extends the reach of the IEEE 40GBASE-SR4 and can achieve distances of up to 300 meters with OM3 fibers and 400 meters with OM4 fibers. The transceiver can be used for native 40G optical links over parallel cables with MPO/MTP connectors. Or it is used in a 4×10G mode with parallel to duplex fiber breakout cables for connectivity to four 10GBASE-SR interfaces. Each 10-gigabit lane of this transceiver is compliant to IEEE 10GBASE-SR specifications. This transceiver is optimized to guarantee interoperability over the complete specification range of 10GBASE-SR.

Cisco QSFP 40G BiDi

The Cisco 40G BiDi QSFP+ transceiver is a pluggable optical transceiver with a duplex LC connector interface for short-reach data communication and interconnect applications. It consists of two 20-Gbps transmit and receive channels in the 832nm to 918nm wavelength range, enabling an aggregated 40-Gbps link over a 2-strand multimode fiber connection. This transceiver can be reused in the existing 10 Gigabit duplex MMF infrastructure for migration to 40 Gigabit Ethernet connectivity. Besides, it supports link lengths of 100m and 150m on laser-optimized OM3 and OM4 multimode fibers, respectively. Generally, this transceiver is compatible with the QSFP MSA specification, which allows customers to use it on all QSFP 40-Gbps platforms.

Conclusion

40G Ethernet networking which supports higher bandwidth is the new trend for big data center. Of all the 40G optical options, these Cisco 40GBASE QSFP+ transceivers offer high-density and low-power 40 Gigabit Ethernet connectivity options for data center. Cisco QSFP-40G-LR4, Cisco QSFP-40G-SR4, Cisco QSFP-40G-CSR4, and Cisco QSFP 40G BiDi , these QSFP+ transceivers have different applications and can meet different needs. All you need to do is choose the suitable one for your unique applications.