Optical transceivers utilized in networking hardware are a wonderful thing. They make it possible for one piece of equipment, like a switch, to maintain various wiring and transmission formats. However, despite their usefulness, there is an issues with optical transceivers: trying to determine which type(s) you need.
With that said, we wanted to do a quick rundown of biggest differences between the most commonly used transceiver types that are offered by major manufacturers and third-party transceiver manufacturers. Though this is not nearly what should be thought of as a thorough list, it does cover what is most often asked for and installed. Keep in mind, the saying, “you can’t fit a square peg into a round hole” can quite literally be applied here, which means that even if you are partial to the specs of one of the styles, that doesn’t mean it can be used in all equipment.
So, without further ado, let’s get started…
A Basic Guide to the Popular Optical Transceiver Formats: SFP, QSFP, XFP and More
Short for Small Form Factor Pluggable, SFP was once the most commonly used transceiver formats; however, it is being used less and less because of the restrictions in format. It is both hot-swappable and pluggable, which allows for a greater amount of density of ports within the networking equipment. Though SFP has a theoretical maximum speed of 5Gbps, when applied, it is most commonly used for a 1Gbps connection.
SFP is available in a lot of options and supports many types of wiring, such as Ethernet, SONET and single-mode fiber.
The improved version of SFP, SFP+ can support more data. The highest transmission speed is 16Gpbs, though it is usually used for 10Gbps fiber or Ethernet connections. It also uses a better encoding method.
First defined in 2002, XFP is one of the original transceiver standards that is still being used. While new equipment that supports XFP natively is not very common, it still remains popular because of its legacy use.
XFP can support as much as 10Gbps connections for fiber, Ethernet or SONET. When used in fiber applications, it makes high-density multiplexing for better transmission possible. It also supports –LC fiber connectors. The biggest benefit of XFP compared to other 10-Gigabit formats, such as SFP+ is that it uses less power.
An acronym for Standing Quad Small Form Factor Pluggable, QSFP is four SFP+ connections that have all been placed into one transceiver. The standard QSFP format supports as much as 40Gbps on Ethernet or Fiber, as well as SONET and Infiniband.
The QSFP+ transceiver is basically any type of QSFP transceiver that supports data rates that run higher than 40Gpbs. Presently, the highest speed format is QSFP28, which makes four 28Gpbs connections at the same time possible.
This is one of the latest transceiver formats. C= centum, the Latin for 100. It is mostly intended to be used with 100Gbps Ethernet systems.
There are several subvarients of the CFP format, and the latest has a power draw that is less than 6W.