To meet the never-ending requirement for faster rates of data transmission, Ethernet technology has evolved from 100Mps into 10G, or even 100G . And at present, 10G is the most commonplace one. In a 10G network, fiber optic cabling plays an important role to connect the servers, storage and switches together to setup data center. There are several options for 10GbE direct cabling, including SFP+ transceiver (commonly used with patch cables), SFP+ DAC (direct attach cable) and SFP+ AOC (active optical cable). Each of them has advantages and disadvantages. Today’s blog will introduce them respectively. You can choose the best one according to your requirements.
In this connection method, there are two things required on each side—10G pluggable SFP+ transceivers and fiber optic patch cables. SFP+ transceivers comes in various types that can drive signals across fiber optic cables with different maximum distances, so you can select the appropriate one. And when you choose patch cables, you should pay attention to the ports on SFP+ transceivers. (tips: SFP+ transceiver uses duplex LC port, thus duplex LC patch cord should be used to connect SFP+.) This connectivity method supports fiber cables that are really long. For example, a Cisco 10GBase-SR SFP+ can reach as far as 300 m, so it is possible for you to connect a server at one end of a data center to a switch several racks away or even at the other end. Nevertheless, the pluggable transceiver parts are quite expensive. There is a picture of this connection method.
As the development of fiber technology, someone may deem that copper technology is out of fashion, but this is not true for direct attach cable. SFP+ direct attach cable (DAC), also known as 10GSFP+Cu, is a copper 10GBase Twinax cable that comes in either an active or passive twinax cable assembly and connects directly into SFP+ modules, which are permanently attached to both ends of the cables. But compared to real optical modules, the modules at both sides are without expensive optical lasers. Thus, SFP+ DAC is much cheaper and has lower power consumption than the regular SFP+ optics. With low-power, low-cost, low-latency, and the added advantage of using less bulky cables, SFP+ direct attach cable today is ideal for in-rack 10G connections between servers and switches. However, due to the nature of electrical signals, direct attach copper cable is vulnerable to the effects of EMI, such as undesirable response, degradation, or complete system failure. Here is an image of SFP+ direct passive attach cable:
Generally, the wire transmission of optical communication should belong to the passive part, but AOC is an exception. SFP+ active optical cable (AOC) uses optical fiber and electrical-optical conversion on the cable ends to improve speed and data transmission distance of the cable without sacrificing compatibility with standard electrical interfaces. Compared to direct attach cable for data transmission, active optical cable takes more advantages, like lighter weight, high performance, low power consumption, low interconnection loss, EMI immunity and flexibility. Besides, with industry-leading VCSEL technology and an advanced new light engine design, the SFP+ AOC is perfect for high-performance computing clusters, 4G or 8G fibre channel applications (4GFC/8GFC), 1x InfiniBand QDR, DDR, SDR, network interfacing applications, etc. However, every coin has two sides. The only drawback of AOC is that it is a little more expensive for customers than direct attach cable. The following picture shows the SFP+ AOC cable:
10G Ethernet has become the prevalent technology which is to upgrade networks and support bandwidth-intensive applications. And SFP+ cables, including SFP+ transceiver option, SFP+ DAC cable and SFP+ AOC cable are indispensable cabling solutions for 10 Gigabit network. From this post, you can get some useful references when you choose 10G SFP+ cables. Besides 10G SFP+ cables, FS.COM provides 25G SFP28 cables, 40G QSFP cables, or 100G QSFP28 cables, and so on. Anytime you need related products, FS.COM is a great place to visit.