The range of QSFP+ (Quad Small Form-Factor Pluggable Plus) transceivers can vary depending on the type of optical fiber used and the specific implementation. In general, QSFP+ transceivers can support distances of up to 40 kilometers over single-mode fiber and up to 300 meters over multimode fiber. However, there are also extended reach and long reach QSFP+ modules that can support even greater distances.

What speed is QSFP+ supported?

QSFP+ is the modern incarnation of QSFP. In most data centers, it has completely replaced its predecessor. QSFP+ can reach speeds of 10 Gbps per line. This makes it a 40G connection type that still maintains the small form factor that is essential to so many network designs.

The latest advance on QSFP connections is QSFP28. It expands on the transmission rate per line, and it easily gets throughput beyond 100G.

What are the different types of QSFP+ Transceivers

There’s been a rapid evolution of gigabit ethernet and a growing demand for equipment that handles this advancement. Data centers are now migrating to blazing fast 40G, and QSFP+ transceivers as a necessary component in making sure high speed internet stays high speed.

QSFP+ stands for Quad Small Form-Factor Pluggable Plus. A parallel and hot-swappable fiber optical module that provides high-density 40G connectivity options for high-performance computing networks and modern data centers. It has four independent receive and transmit optical channels that can terminate to another 40G QSFP+ transceiver, or can be distributed to four separate 10 Gigabit SFP+ transceivers. The QSFP+ modules , in a nutshell, connect the entire electrical circuitry of your system to an optical external network.

QSFP+ Interface: LC & MPOThere are a variety of 40G transceivers currently available on the market. However, 40G QSFP+ optics follow the QSFP MSA standard which dictates that 40G QSFP+ connectors can be either 12-fiber MPO or duplex LC. Which are the MPO and the LC.

What are the differences between these two interfaces?

To put it simply, 40G QSFP+ transceivers that have an LC interface are used in transmitting data over long distances via single mode fiber (SMF), while transceivers with an MPO interface (except for 40GBase-PLR4 and 40GBase-PLRL4) are deployed for data transmission over short distances via multimode fiber (MMF). In addition to that, MPO interfaced QSFP+ transceivers can be used in 4x10G connectivity using a breakout cable, compared to LC interfaced ones that can’t be divided into 4x10G since they use 4 wavelengths on one pair of SMF.

Let’s delve deeper and understand how 40G QSFP+ transceivers with LC interface work. From the transmitting side, 4 channels of 10G serial data streams that have different wavelengths are sent over to laser drivers. These same laser drivers control the DML or directly modulated lasers using wavelengths. Then the DML outputs are multiplexed optically to a singlemode fiber via a standard LC connector, combining as 40G. On the receiving side, the 40G signal is demultiplexed into four separate 10G streams at different wavelengths. Each single wavelength light is acquired by a diode and amplified by a TIA and then comes out as electric data.

The working principle of a 40G QSFP+ transceiver with an MPO interface can be explained by starting from the transmitting side, when it transmutes parallel electrical input signals into parallel optical signals via a laser array. The optical signals are then sent through the MPO-terminated MMF ribbon. In the other side, the receiver transforms parallel optical input signals into parallel electrical output signals using a photo detector array.

What is difference between SFP and QSFP?

QSFP vs SFP specification is the second identification. Detailed factors include standard, connector, fiber type, wavelength, data rate, transmission distance, etc.

SFP is applied in SONET, Gigabit Ethernet, Fibre Channel, and other communications standards. QSFP+, as the expansion of QSFP, supports 10-Gigabit Ethernet, 10G Fibre Channel, and InfiniBand.

In function capacity, QSFP vs SFP differs in the channel quantities and data rates.

SFP has only one channel while QSFP has four. SFP speeds up to 1Gbps, and SFP+ up to 10Gbps. However, The initial QSFP supports 4Gbps, and the new version QSFP+ supports 40Gbps. Further, a QSFP+ functions the same as 4 separate SFP+ modules, which means an increase in port density and overall system cost-efficiency.