Simple Guide to Common Optical Transceiver Formats
Optical transceivers are widely used in networking hardware installations. They are widely used because they make it possible for a switch to support various types of wiring and transmission formats. The main issue is trying to make out which of the different transceiver types is most suitable for an given application.
Here, we help you understand the main difference between various transceiver types. We cover the most commonly used and installed optical transceiver modules and explain why it is important that you should use the right transceiver type for the right purpose.
Small Form Factor Pluggable (SFP) is the most widely used optical transceiver format. But it does have some limitations. SFP transceivers are hot-swappable and pluggable. They work with a high density of ports and have a maximum speed of 5Gbps, at least in theory. Practically, though, these transceivers are used with 1Gbps connection.
SFP supports a number of different wiring types, such as Ethernet, single-mode fiber, SONET and multi-mode fiber.
SFP+ is an improved version of SFP. It supports more data than SFP does. The highest transmission speed you can get with SFP+ is 16Gbps. SFP+ is commonly used with Ethernet connections or 10Gbps fiber. It uses a different encoding method compared to SFP and carries more data than SFP does on a similar type of hardware.
XFP is a traditional transceiver standard, which has been in use for a long time. It was defined way back in 2002. It is rare to find new equipment that supports XFP, but transceivers based on this format are still popular because of legacy use.
XFP can work with 10Gbps connections for SONET, fiber and Ethernet. It works very well with fiber, as it supports high-density multiplexing which gives you a much improved level of transmission. It also supports -LC fiber connectors.
One reason to use XFP compared to other 10-Gigabit formats such as SFP+ is that it requires very little power consumption, and is more energy efficient.
QSFP means Quad Small Form Factor Pluggable. It consists of 4 SFP+ connections which are combined together into a single transceiver. A typical QSFP format supports 40Gbps of data on SONET, Ethernet or Fiber, as well as on Infiniband.
The QSFP format has been changing constantly. But it is rare to find a “basic” QSFP connection or cabling today, as QSFP+ is generally preferred.
There really isn’t much of a difference between QSFP and QSFP+, but the latter is based on incremental improvements made over many years. QSFP+ works as any QSFP- style transceiver and supports data rates of 40Gbps and above.
As of now, QSFP28 is the highest speed format, which supports 4 simultaneous 28Gbps connections, or as much as 112Gbps. This format is available in different types for fiber and copper connections.
CFP is the latest of all transceiver formats. “C” is for centum, which is the Latin word for hundred. This transceiver format supports 100Gbps Ethernet systems.
This format comes with many different subvarients, such as CFP, CFP2, and CFP4, which are not inter-compatible by any means. Every new generation of CFP transceivers is more energy-efficient and comes with a smaller build compared to previous generations.
CFP4 is the latest – it comes with a power draw of less than 6W, which compares very well with the power draw of 24W of the original CFP format. CFP4 supports 100Gbps Ethernet in 4×25 or 10×10 lane configurations.