WHAT ARE THE DIFFERENCES
BETWEEN SFP, SFP+, XFP,
QSFP/QSFP+ AND CFP?
Recently, we can see some products information about fiber optic transceivers, such SFP,
SFP+, XFP, QSFP and QSFP+ on facebook. Have you ever wondered what are they
respectively for and what’s the difference between them? Today, we are going to talk
something about them in this paper.
SFP
SFP, small form-factor pluggable for short, is a compact, hot-pluggable transceiver
module used for both telecommunication and data communications applications.
SFPtransceiver can be regarded as the upgrade version of GBIC module. Unlike GBIC
with SC fiber optic interface, SFP is with LC interface and the main body size of SFP is
only about half of GBIC, which makes the SFP space saving. SFP interfaces a network
device mother board (for a router, switch, media converter or similar devices) to a fiber
optic or copper networking cable. Meanwhile, SFP is a popular industry format supported
by many network component vendors. SFP transceiver modules are designed to support
SONET, Gigabit Ethernet, Fibre Channel, and other communications standards.
SFP+
SFP+ is an enhanced version of the SFP that supports data rates up to 10 Gbit/s. SFP+
supports 8 Gbit/s Fibre Channel, 10-gigabit Ethernet and Optical Transport Network
standard OTU2. It is a popular industry format supported by many network component
vendors. Initial standard applications focused on 8G Fibre Channel, 10G Ethernet and
10G Fibre Channel, where the electrical interface to the host board is a standardized
serial interface called SFI. The applications have expanded to include SONET OC-192,
SDH STM-64, OTN G.709, CPRI wireless, 16G Fibre Channel, and the emerging 32G
Fibre Channel application.
XFP
XFP has appeared before the SFP+. It is also a standardized form factor for serial 10
Gb/s fiber optic transceivers. It is protocol-independent and fully compliant to the
following standards: 10G Ethernet, 10G Fibre Channel, SONET OC-192, SDH STM-64
and OTN G.709, supporting bit rate from 9.95G through 11.3G. XFP transceivers are
used in datacom and telecom optical links and offer a smaller footprint and lower power
consumption than other 10 Gb/s transponders. The electrical interface to the host board
is a standardized serial 10 Gb/s interface called XFI.
QSFP/QSFP+
QSFP is short for quad (4-channel) small form-factor pluggable. It is a compact, hot-
pluggable transceiver also used for data communications applications. QSFP+ evolved
as the standard to support 10Gb/s data rates per SFF-8436. Compared with QSFP+,
QSFP products support Quarter Small Form-factor Pluggable with the different data rate
so that there is no change in the product solution. Nowadays, QSFP+ gradually replace
QSFP and is widely used by people as it can provide higher bandwidth.
CFP
CFP, namely C form-factor pluggable, is a multi-source agreement to produce a
common form-factor for the transmission of high-speed digital signals. The c stands for
the Latin letter C used to express the number 100 (centum), since the standard was
primarily developed for 100 Gigabit Ethernet systems. It can support a wide range of 40
and 100 Gb/s applications such as 40G and 100G Ethernet, OC-768/STM-256, OTU3,
and OTU4.
Differences of These Fiber Optic Transceivers
Through the above definitions of each type of fiber optic transceiver module, you may
have a further understanding of them. Now, we are comparing these transeiver one by
one.
SFP vs SFP+: Simple to understand, SFP+ is an update vision of SFP. SFP usually
support 1.25Gbit/s to 4.25 Gbit/s while SFP+ supports data rates up to 10 Gbit/s.
SFP and SFP+ have the same size and appearance, but in different standard
which SFP is based on IEEE802.3 and SFF-8472.
SFP+ vs XFP: In comparison to earlier XFP modules, SFP+ modules leave more
circuitry to be implemented on the host board instead of inside the module. The
size of SFP+ is smaller than XFP, thus it moves some functions to motherboard,
including signal modulation function, MAC, CDR and EDC. XFP is based on the
standard of XFP MSA while SFP+ is compliance with the protocol of IEEE 802.3ae,
SFF-8431, SFF-8432.
SFP+ vs QSFP+: QSFP+ has four-channel SFP+ interfaces which can transfer
rates up to 40Gbps. And of course they have different standards.
CFP vs QSFP+: QSFP+ (Quad Small Form-Factor Pluggable Plus) modules offer
customers a wide variety of high-density 40 Gigabit Ethernet. The CFP is a hot-
pluggable transceiver module form factor that supports a wide range of 40Gb/s
and 100Gb/s applications such as 40G and 100G Ethernet.
