The Cisco® 40GBASE QSFP+ (Quad Small Form-Factor Pluggable Plus) modules offer customers a wide variety of high-density 40 Gigabit Ethernet connectivity options for data center, high-performance computing networks, enterprise core and distribution layers, and service provider transport applications.

Main features of Cisco 40GBASE QSFP+ modules include:

- Support for 40GBASE Ethernet
- Hot-swappable input/output device that plugs into a 40-Gigabit Ethernet QSFP+ Cisco switch port
- Flexibility of interface choice
- Interoperable with other IEEE-compliant 40GBASE interfaces available in various form factors
- Support for "pay-as-you-populate" model
- Support for the Cisco quality identification (ID) feature which enables a Cisco switch to identify whether the module is certified and tested by Cisco

Cisco QSFP-40G-SR4
The Cisco 40GBASE-SR4 QSFP+ Module supports link lengths of 100m and 150m respectively on laser-optimized OM3 and OM4 multimode fiber cables. It primarily enables high-bandwidth 40G optical links over 12-fiber ribbon r cables terminated with MPO/MTP multi-fiber connectors. It can also be used in 4x10G mode along with ribbon to duplex fiber breakout cables for connectivity to four 10GBASE-SR optical interfaces. Maximum channel insertion loss allowed is respectively 1.9dB over 100m of OM3 cable or 1.5dB over 150m of OM4 cable.

Cisco QSFP-40G-CSR4
The Cisco 40GBASE-CSR4 QSFP+ Module is similar to the 40GBASE-SR4 interface extends supported link lengths to 300m and 400m respectively on laser-optimized OM3 and OM4 multimode fiber cables. Each 10-gigabit lane of this module is compliant to IEEE 10GBASE-SR specifications. This module can be used for native 40G optical links over 12-fiber ribbon cables with MPO/MTP connectors, or in 4x10G mode with ribbon to duplex fiber breakout cables for connectivity to four 10GBASE-SR interfaces. Maximum channel insertion loss allowed is respectively 2.6dB over 300m of OM3 cable or 2.9dB over 400m of OM4 cable.

Cisco QSFP-40GE-LR4
The Cisco 40GBASE-LR4 QSFP+ Module (Figure 2) supports link lengths of up to 10km over a standard pair of G.652 single-mode fiber with duplex LC connectors. The 40 Gigabit Ethernet signal is carried over four wavelengths. Multiplexing and demultiplexing of the four wavelengths are managed within the device.

Operational conditions
Operating temperature (T-T)	0 - 70 °C
Storage temperature (T-T)	-40 - 85 °C
Operating relative humidity (H-H)	10 - 80%
Storage relative humidity (H-H)	10 - 85%
Performance
SFP transceiver type	Fiber optic
Maximum data transfer rate	40000 Mbit/s
Interface type	QSFP+
Multi-mode fiber (MMF) supported	Yes
Fiber optic connector	LC
Fiber cable diameters supported (core/cladding)	50/125 µm
SFP transceiver standard	SR
Maximum transfer distance	150 m
Wavelength	850 nm
Cabling technology	40GBASE-SR4
Auto MDI/MDI-X	Yes
Features
Certification	MSA
Logistics data
Harmonized System (HS) code	85369010