QSFP28 100GBASE-SR4 vs. CFP 100GBASE-SR10 Optical Transceiver

Nowadays, 100G Ethernet is becoming more and more popular in the field of optical communication, and also becomes a trend in the data center. Currently, there are two main series about 100G optical transceiver in the market: QSFP28 series and CFP series. With respect to these two series, we have talked about the differences between QSFP28 and CFP optical module in the previous articles. Then in this article, we will continue this topic, but it is to explore the differences between the QSFP28 100GBASE-SR4 and CFP 100GBASE-SR10 optical transceiver in several aspects of the two main physical layer standards about short distance interconnection.

The comparison about 100GBASE-SR4 and 100GBASE-SR10 will be made from the following perspectives:

1. Comparison in the Components of Optical Transceiver

CFP is a typical 100GBASE-SR10 component. It is defined by a multi-source agreement formulated by the internal of the manufacturers with fierce competition. CFP appears after small form pluggable (SFP) interface, but it is extraordinary to realize 100Gbps data transmission via 10x10Gbps channel. While QSFP28 is the latest 100G Ethernet component. QSFP28 uses 4*25G data transmission channels, each of which is available for the latest 100/50/25G optical module and device interconnect. Therefore, it is the most representative component of 100GBASE-SR4.

Conclusion: Seen from the form factor, QSFP28 is more popular than CFP.

2. Comparison in Size

The transceivers of the 100GBASE-SR4 and 100GBASE-SR10 interfaces respectively correspond to QSFP28 and CFP. Therefore, they have apparent differences in size. As shown in the following figure, the size of the CFP is much larger than that of the QSFP28. It is obvious that CFP is not suitable for high-density applications. By comparison, QSFP28 increases the density of the front panel, reduces power consumption and is cheaper. As a result, QSFP28 is more popular than CFP.

Conclusion: as high density becomes a trend of data center, QSFP28 (100GBASE-SR4) has more advantages than CFP (100GBASE-SR10) to meet this need.

3. Comparison of Photoelectric Channel Diagram

The following diagram shows the basic structure of QSFP28 100GBASE-SR4 and CFP 100GBASE-SR10.

Conclusion: 100GBASE-SR4 can achieve higher data transmission rate in each channel with fewer channels, so that the port density can be reduced.

4. Comparison of Cable and Connector Type

Both 100GBASE-SR4 and 100GBASE-SR10 use optical laser to optimize the multimode fiber (OM3/OM4) to transmit signals. But 100GBASE-SR4 utilizes a standardized QSFP MPO/MTP cable with 12-fibers(4 Tx and 4 Rx, each channel offers 25Gbps throughput) to connect, while at the same time that 100GBASE-SR10 uses a MPO/MTP cable with 2 * 12 or 24 fibers(10 Tx and 10 RX, each LAN offers throughput of 25Gbps) to transmit, 100GBASE-SR10 also uses 2 x 12 or 24 fibers MPO/ MTP cable (10 Tx and 10Rx, each channel provides a throughput of 10Gbps) to connect.

The interface between 100GBASE-SR4 and 100GBASE-SR10 can respectively reach 4 * 25Gbps and 10 * 10Gbps data transmission rate. Therefore, they only need to use MPO/ MTP to LC trunk jumper to easily accomplish the upgrade from 25GbE/10GbE to 100GbE.

Conclusion: 100GBASE-SR4 uses 12-fibers MPO/MTP jumpers, while 100GBASE-SR10 uses one or two MPO/ MTP jumpers with 12 fibers or 24 fibers. For the point to point interconnection of 100G, 100GBASE-SR4 is more cost-effective. Simultaneously, for network migration, 100GBASE-SR4 is also with more advantages because it has fewer branches and can greatly reduce the cost of cable management.

Summary

In a word, the advantage with respect to the layout of the host board greatly reduces the number of wiring. 100GBASE-SR4 is more competitive in cost and power consumption, so 100GBASE-SR10 is now slowly withdrawn from the market. While Gigalight, as a company dedicated to the R&D and design of optical communication products as well as to providing system solutions, also supplies a series of 100GBASE-SR4, which can be compatible with major brand switches. More details are at www.gigalight.com.