How to Convert QSFP+ Ports to SFP+ Ports?

With the arrival of 40G Ethernet, many enterprise users are beginning to consider the problem of seamlessly migrating to a 40G network while taking full advantage of their current 10G network infrastructure, specifically the problem of how to pair 40G switches with QSFP+ ports with existing 10G devices with SFP+ ports, such as switches and servers. In this article, the QSFP+ optical module supplier will share three common solutions to teach you how to directly convert QSFP+ ports to SFP+ ports. 

Solution 1: QSFP+ Branch Cable

The first method of directly converting QSFP+ to SFP+ ports is to use QSFP+ branch cables, which are available in both DAC high-speed cables and AOC active optical cables. In most cases, both types have one QSFP+ optical module connected to one end and four SFP+ optical modules connected to the other end, which becomes a QSFP+ to SFP+ branch cable. In addition, there is another type of AOC branch cable, namely QSFP+ to 4 LC duplex AOC cable, with QSFP+ at one end and duplex LC fiber patch cable at the other end, which can also achieve QSFP+ to SFP+ conversion when another SFP+ optical module is added for use.

Regardless of which type of branch cable is chosen, by connecting one end to a QSFP+ switch port and the other end to multiple 10G devices (no more than 4) with SFP+, these QSFP+ branch cables can split 40G into 4 x10G links.

 QSFP+ ER4

Option 2: MTP/MPO to LC branch patch cable

The second method of converting QSFP+ to SFP+ ports is to use MTP/MPO to LC branch patch cables. This option is similar to the one mentioned earlier, but without pre-connected optical modules at both ends. For example, an 8-pole MTP/MPO has an MTP/MPO connector on one end and is usually equipped with four LC duplex connectors on the other end. To achieve the conversion from 40G to 10G, it is necessary to equip each MTP/MPO to LC branch patch cable with one QSFP+ optical module with MTP/MPO connector and four SFP+ modules with duplex LC connectors. As shown in the figure below, the conversion can be achieved by connecting the patch cords to the corresponding 10G and 40G modules and then inserting the modules into the matching QSFP+ ports or SFP+ ports.

Option 3: CVR-QSFP-SFP10G QSA conversion module

Another way to directly convert QSFP+ to SFP+ ports is through the 10G converter CVR-QSFP-SFP10G. The QSFP+ to SFP+ converter has a QSFP+ package with an internal SFP+ module slot that allows devices with 40G QSFP+ ports and 10G SFP+ ports to be connected seamlessly. The 40G-10G connection is achieved by inserting the SFP+ module into the QSFP+ to SFP+ converter and then connecting the converter to the QSFP+ port. The QSFP+ to SFP+ converter acts as an interface for the SFP+ module in the link.