Common DAC high-speed cable classification

DAC high-speed cable (Direct Attach Cable) is generally translated as direct cable, direct-connect copper cable or high-speed cable. It is defined as a low-cost short-distance connection scheme that replaces optical modules. Both ends of the high-speed cable have modules Cable assemblies, non-replaceable ports, module heads and copper cables cannot be separated, but compared to optical module active optical cables (Active Optical Cables), the connector modules on high-speed cables do not have expensive optical lasers and other electronic components, so Significant savings in cost and power consumption in short-distance applications. With higher Ethernet speeds, cloud computing, the Internet of Things, and virtual data centers, more requirements have been placed on data center operators. The data speed is actually on the way to 400G, so in addition to the connection within 3-5m in the server, DAC can also be used (5-7 meters need to use special insulating materials to meet the characteristic requirements). The connection beyond these distances is generally realized by AOC.

10G SFP+ to SFP+ High Speed Cable

The 10G SFP+ to SFP+ DAC uses a passive twinaxial cable assembly and connects directly to the SFP+ module, featuring high density, low power, low cost, and low latency.

What types of 10G SFP+ to SFP+ high-speed cables are available?

Generally speaking, there are three types of 10G SFP+ to SFP+ high-speed cables:

10G SFP+ passive copper core high-speed cable (DAC),

10G SFP+ Active Copper Core High Speed ​​Cable (ACC),

10G SFP+ Active Optical Cable (AOC),

They are suitable for network connections within a rack and between adjacent racks and are extremely cost-effective.

The SFP+ passive copper core high-speed cable provides a direct electrical interface between the two ends of the corresponding cable, and the connection distance can reach 12m. However, due to the heavy weight of the cable and considering the problem of signal integrity, its use length It is generally limited to between 7m and 10m.

40G QSFP+ to QSFP+ High Speed Cable

A 40G high-speed cable (DAC) refers to a connecting cable with fiber optic transceivers at both ends, which can achieve 40Gbps data transmission and is a cost-effective high-speed interconnection solution. The more common 40G high-speed cables can be divided into three types: 40G QSFP+ to QSFP+DAC, 40GQSFP+ to 4*SFP+DAC, and 40GQSFP+ to 4XFP+DAC.

40G QSFP+ to QSFP+ DAC is composed of two 40G QSFP+ optical transceivers and copper core wires. This high-speed cable can be used to realize the interconnection of existing 40G QSFP+ ports to 40G QSFP+ ports, generally only within 7m. distance.

40G QSFP+ to 4×SFP+ DAC is composed of one 40G QSFP+ optical transceiver, copper core wire and four 10G SFP+ optical transceivers. One end is 40G QSFP+ interface, which meets the requirements of SFF-8436, and the other end is four 10G SFP+ interfaces. , in line with the requirements of SFF-8432, mainly used to realize the interconnection between 40G and 10G equipment (NIC/HBA/CNA, switch equipment and server), according to the customer’s requirements for the length of the cables at both ends, generally only within 7m. Distance, is currently the most economical and simple to achieve switch port conversion.

The 40G QSFP+ to 4XFP DAC is composed of one 40G QSFP+ optical transceiver, copper core wire and four 10G XFP optical transceivers. Since the XFP fiber optic transceiver does not have the DAC copper cable standard, the signal compensation given by the device is low, and the loss of the cable itself is very large. It can only be used for short-distance transmission, generally within a distance of 2m. Therefore, this high-speed cable can be used for Interconnects existing 40G QSFP+ ports to 4 XFP ports.

25G SFP28 to SFP28 High Speed Cable

25G SFP28 to SFP28 DAC can provide customers with 25G high-bandwidth data interconnection capability, in line with IEEE P802.3by Ethernet standard and SFF-8402 SFP28, and is widely used in data center or supercomputing center system scenarios

100G QSFP28 to QSFP28 High Speed Cable

100G QSFP28 to QSFP28 DAC can provide customers with 100G high-bandwidth data interconnection capability, providing 4 duplex channels, each channel can support up to 25Gb/s operating rate, and the aggregation bandwidth is 100Gb/s, in line with the SFF-8436 specification, used in Connection between devices with QSFP28 ports.

100G QSFP28 to 4*SFP28 High Speed Cable

One end of the 100G QSFP28 to 4 SFP28 DAC is a 100G QSFP28 interface, and the other end is 4 25G SFP28 interfaces, which can provide customers with 100G high-bandwidth data interconnection capabilities, in line with SFF-8665/SFF-8679, IEEE 802.3bj and InfinibandEDR standards, Widely used in data center or super computing center system scenarios.