At present, most enterprise network and data center users adopt the QSFP+to SFP+port splitting scheme to efficiently and smoothly upgrade the existing 10G network to 40G network to meet the growing demand for high-speed transmission. This 40G to 10G port splitting scheme can make full use of existing network equipment, help users save costs and simplify network configuration. So how to realize 40G to 10G transmission? This article will share the splitting scheme to help you realize 40G to 10G transmission.
Precautions for 40G to 10G port splitting
Generally, most brand switches on the market support port splitting. You can check whether your device supports port splitting by checking the switch's product manual or directly asking the supplier. Note that in some special cases, the ports of the switch cannot be split. For example, when the switch acts as a Leaf switch, some of its ports do not support port splitting; When the port of the switch acts as a stacking port, the port cannot be split.
When splitting a 40G port into 4 * 10G ports, make sure that the port is running at 40Gbps by default and other L2/L3 functions are not enabled. Note that during this process, the port still operates at 40Gbps until the system restarts. Therefore, after using the CLI command to split the 40G port into 4 * 10G ports, restart the device to ensure that the command takes effect.
QSFP+to SFP+cabling scheme
At present, the connection schemes for QSFP+to SFP+are mainly as follows:
QSFP+to 4 * SFP+DAC/AOC direct cable connection scheme
Whether you choose QSFP+to 4 * SFP+DAC copper-core high-speed cable or QSFP+to 4 * SFP+AOC active optical cable, the connection mode is the same, because the design and use of DAC and AOC optical cables are similar. As shown in the figure below, one end of the DAC and AOC direct cable is a 40G QSFP+connector, and the other end is four independent 10G SFP+connectors. The QSFP+connector can be directly inserted into the QSFP+port of the switch. It has four parallel two-way channels, and each channel can work at a maximum rate of 10Gbps. Since DAC high-speed cables use copper media for transmission and AOC active optical cables use optical fiber for transmission, the transmission distance they support is also different. Generally, DAC copper core high-speed cables have shorter transmission distance, which is the most obvious difference between the two.
In the 40G to 10G split connection, you can use the 40G QSFP+to 4 * SFP+direct connection cable to directly connect the switch without purchasing additional optical modules to help you save network costs and simplify the connection process. However, the transmission distance of this connection mode is limited (DAC ≤ 10m, AOC ≤ 100m). Therefore, DAC or AOC direct optical cable is more suitable for the connection inside the machine cabinet or between two adjacent cabinets.
40G QSFP+to 4 * LC duplex AOC branch active optical cable
40G QSFP+to 4 * LC duplex AOC branch active optical cable is a special type of AOC active optical cable. One end of it is a QSFP+connector, and the other end is four independent LC duplex jumpers. If you plan to use the branch active optical cable to realize the application of 40G to 10G, you also need to match four SFP+optical modules, that is, the QSFP+interface of the QSFP+to 4 * LC duplex active optical cable can be directly inserted into the 40G port of the device, and the LC interface needs to be inserted into the corresponding SFP+optical module on the device. Because most devices are compatible with LC interfaces, this connection mode can better meet the needs of most users.
Post time: Mar-06-2023
