There was a time when 10G to 40G migration was a hot spot, and as the only available 40G transceiver, 40G QSFP+ has occupied the major position in the market. However, the pace of development has never stopped and the demand for higher speed data transmission keeps growing. And now, many data center managers set their sight on 100G Ethernet. As an important component in 100G optical links, 100G transceivers gradually gain great popularity among data center managers. But unlike 40G transceiver, 100G transceiver has several types, such as CFP/CFP2/CFP4, CXP and QSFP28. How much do you know about them? This article is going to give an overview of 100G transceivers.
The letter “C” in CFP/CFP2/CFP4 stands for 100. The CFP transceiver is specified by MSA between competing manufacturers and it can support 100Gbps over both single-mode and multimode fiber. The electrical connection of a CFP uses 10 x 10G lanes in each direction (RX, TX) while the optical connection can support both 10 x 10G and 4 x 25G variants of 100G interconnects. With improvement in higher performance and higher density, CFP2 and CFP4 appeared. While electrical similar, they specify a form factor of 1/2 and 1/4 respectively in size of CFP. CFP, CFP2 and CFP4 modules are not interchangeable, but would be inter-operable at the optical interface with appropriate connectors.
Here is a table for you which shows five typical transceiver types. We can get that CFP-SR10-100G is structured with 24-fiber MTP connector interface, so it can be used with multimode MTP 24 to MTP 24 100g trunk cable to support 100G optical links over short distance; designed with LC duplex interface, CFP-LR4-100G, CFP-ER4-100G, CFP2-LR4-100G and CFP4-LR4-100G are used with LC duplex patch cable to support 100Gbps data rate over long distance.
The CXP was created to satisfy the high-density requirements of the data center, targeting parallel interconnections for 12x QDR InfiniBand (120G), 100G, and proprietary links between systems collocated in the same facility. The CXP is 45 mm in length and 27 mm in width, making it slightly larger than an XFP. It includes 12 transmit and 12 receive channels in its compact package. This is achieved via a connector configuration similar to that of the CFP.
Similar to 40G QSFP+, 100G QSFP28 also offers four independent transmit and receiver channels, but each channel is capable of 25Gbps data rate for an aggregate data rate for 100Gbps. With an upgraded electrical interface to support signaling up to 25Gbps signals, the 100G QSFP28 makes it as easy to deploy 100G network as 10G networks. When compared to any of the other alternatives, the 100G QSFP28 increases density and decreases power and price per bit, but It has to noted that 100G QSFP28 has the same physical size as 40G QSFP+. Just like 40G QSFP+, 100G QSFP28 can be both deployed for short data transmission distance over multimode fiber and long data transmission distance over single mode fiber. For example, 100GBASE-PSM4 QSFP28 can be used with MTP single mode cable to support 100G data rate with link length up to 500 meters.
Now is the time of 100G Ethernet and 100G transceivers are indispensable to complete the 100G optical links. As there are various types of 100G transceivers available on the market, it is necessary to choose the best suitable one for your network deployment.