What are the different types of QSFP+ Transceivers?
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 & MPO
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
. Which are the MPO and the LC. What are the differences between these
To put it
QSFP+ transceiversthat 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 canít be divided
into 4x10G since they use 4 wavelengths on one pair of SMF.
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.
working principle of a40G QSFP+
transceiverwith 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.
Which QSFP+ Type Is Right For You?
transceivers also come in several ratings. It is important to know which
category best suits your network setup.
40GBase-SR4is probably the most
widely-used and most popular 40G transceiver for short distance transmission,
mostly link lengths of 100m and 150m on OM3 and OM4 multimode fibers. It is an
MPO-interfaced parallel fiber optic transceiver with a 4x10G transmission
pattern. The 40GBase-SR4 can achieve simultaneous 40G signal sending and
receiving with the help of four 10G SFP+ lanes in one module. You can usually
see this type of transceiver being used in data centers to interconnect two
switches with 12 lane ribbon cables.
is used for short distance transmission, the 40GBase-LR4, on the other hand, is
for long range transmission of data. Though they use the same multi-lane
technology, the LR4 differs in that instead of using a single fiber strand for
each lane, it multiplexes all four sending lanes onto one fiber strand and all
four receiving lanes onto another single fiber strand. This transceiver type
supports link lengths of up to 10kms via a single-mode fiber cable with duplex
principle behind the40GBase-CSR4module is the same
as the 40GBase-SR4 in which they both have an MPO interface. The difference
though, is that the CSR4 can be considered as an upgrade of the SR4 because it
can support longer transmission of data. Up to 300m using OM3 and 400m on OM4.
Lite or more commonly known as
has the same fundamentals as the 40GBase-LR4 in that it is used for long range
40G data transmission over a single-mode fiber cable. The difference though is
that while the LR4 can support link lengths of up to 10kms, the LR4L only goes
up to 2kms.
The 40GBase-ER4 module
can handle long distance transmission of data up to 40kms over SMF fiber with duplex
LC connectors. It works by converting four 10G input channels to four CWDM
optical signals, then multiplexes them into a single 40G channel. On the
receiving end of the module, the single 40G input is demultiplexed into four
CWDM signals, then transforms them to a four channel electrical data output.
todayís high-performance data network scenarios, 40G QSFP+ modules guarantee
high-density, cost-effective and low-power 40G data transmission. Understanding
the different 40G QSFP+ interface, types, and applications is of prime
importance when selecting the best equipment for your data facility.