10G Ethernet network has been commonplace in telecommunication networks for years, but as the more throughputs, more bandwidth and more resource are required to satisfy the demand for higher speed transmission, data center administrators have turned to high rate 40G Ethernet network. With these two Ethernet networks existing in data centers, how can we connect 10GbE equipment with 40GbE equipment together? This post aims to introduce two breakout cabling solutions for connecting high speed switches populated with higher rate 40G modules to 10GbE elements populated with SFP+ modules for short distance transmission.
As we all know, QSFP+ modules terminated with MPO/MTP connector commonly comes in two versions: QSFP-40G-SR4, and QSFP-40G-CSR4. These 40G parallel optical transceivers can support 4x10G modes, which allows new parallel optics active equipment being compatible with existing 10G transceivers. The QSFP+ MTP to 4LC breakout cable as shown below uses a female MTP connector on one end for interfacing with QSFP+ port on the 40G switch, while the other end uses four duplex LC connectors for providing connectivity to the SFP+ port on the 10G switch. With these two QSFP+ modules as we have mentioned above, QSFP+ MTP 4LC breakout cable can be applied in short distance applications for different link lengths.
QSFP-40G-SR4 as shown below is optimized to guarantee interoperability with any IEEE 40GBase-SR4 and 10GBase-SR, so it can be used in a 4x10G mode for interoperability with 10GBase-SR interfaces up to 100 and 150 meters on multimode (OM3 or OM4) MTP to LC breakout cable respectively.
Like 40GBase-SR4, each 10-gigabit lane of QSFP-40G-CSR4 as shown below is compliant to IEEE 10GBase-SR specifications, but it extend the reach to 300 and 400 meters with OM3 and OM4 MTP to LC breakout cable respectively for connectivity to four 10GBase-SR interfaces.
Breakout QSFP+ AOC is a high-performance and low power integrated cable solution which provides less expensive and reliable transport between 10G and 40G applications for the distances of up to 100 meters. It can be terminated with one QSFP+ transceiver at one end, while the other end can be terminated with four SFP+, and four duplex LC connectors—QSFP+ to 4SFP+ AOC and QSFP+ to 4LC AOC.
QSFP+ to 4SFP+ AOC is a cable assembly that is terminated with one QSFP+ and four SFP+ on the either end, which is suitable for very short distances and offers a flexible way to connect within racks and across adjacent racks. It offers IT professionals a cost-effective interconnect solution for merging 40G QSFP+ and 10G SFP+ enabled host adapters, switches and servers. Users can install this breakout cable between an available QSFP+ port on their 40Gbps rated switch and feed up to four upstream 10G SFP+ enabled switches as shown in the image below.
Connection with QSFP+ to 4LC AOC is likely to QSFP+ modules with QSFP+ MTP to 4LC breakout cable, but the modules in this type of breakout AOC is permanently terminated on the end of the cable, which can provide fast and easy installation. The QSFP+ modules of this cable can be used to plug in the 40G device which has QSFP+ port, while on the other end, the four duplex LC connectors are used to separately connect four SFP+ transceivers, which are used to plug in 10G device with SFP+ switched(see in the following image).
Migrating to 40GbE is inevitable with the increasing demand for higher bandwidth, but how can we deal with the 10GbE devices in data center? The text above has provide four effective breakout cabling solutions for 10G to 40G in short distance applications. Which one should be chosen totally depends on your personal needs.