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Different Applications for 10G SFP+ Cables

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10G SFP+ cables are of various kinds, including DACs, AOCs, and other 10G SFP+ optics (10GBASE-SR/LR/ER/ZR and 10GBAE-T copper transceivers) plus patch cables and copper cables, which are widely adopted in data centers to connect servers, storage appliance and switches. Each of them has different application for different distance. Next, we will talk about these cables respectively.

10G DAC: Server to Switch Connectivity

Direct attach cable (DAC) is a type of sheathed high-speed cable featuring SFP connectors on either termination. The main utility of direct attach cables lies in connecting server to switch within the rack. Top-rack interconnections in data centers are made of 10g direct attach cables these days to provide better alternative to RJ 45 connectors, which are losing their foothold because of the bulkier interface and availability of very few equipment and protocol appearing in their compatibility matrix. For any short range connection measuring as small as 5 m to 10 m, a better performing direct attach cable offers easier and more affordable solution. Servers are typically connected to a switch within the same racks. DAC supports link length up to 7 m, making it perfect for servers to switch connections.

FS 10G DACs are available with different lengths with customized services being offered too. And every cable is individually tested on corresponding equipment such as Cisco, Arista, Juniper, Dell, Brocade and other brands, having passed the monitoring of FS intelligent quality control system. Part of the products are shown in the picture below.

10G AOC: Switch to Switch Connectivity

10G active optical cable (AOC) assemblies are high performance, cost effective I/O solutions for 10G Ethernet and 10G Fibre Channel applications, which can also be used as an alternative solution to SFP+ passive and active copper cables while providing improved signal integrity, longer distances, superior electromagnetic immunity and better bit error rate performance. They allow hardware manufactures to achieve high port density, configurability and utilisation at a low cost and a reduced power budget. Unlike DAC, which is often applied in short distance, AOC can achieve transmission distance up to 100 m, so they often used in switch to switch connections.

10G SFP+ Cables

FS active optical cable (AOC) assemblies use active circuits to support longer distances than standard passive or active SFP+ Copper Cables. FS offers Cisco compatible AOC which is designed for high speed, short range data link via optical fiber wire.

10G SFP+ Optics: Server/Storage to Switch Connectivity

10G SFP+ transceivers, including 10GBASE-SR/LR/ER/ZR and 10GBAE-T copper transceiver, are designed for CWDM and DWDM applications. The range of transceivers supports 850nm, 1310nm, 18 channel for CWDM applications and 40 channels for DWDM applications. These optical transceivers are available with short haul or long haul receivers. Since server or storage to switch connection requires reliable, scalable and high-speed performance, transceivers plus patch cables are usually adopted to achieve such a connection.

10G SFP Cables

FS 10G transceivers are of various types, including GBIC, SFP+, XFP, X2, XENPAK optics, which can be deployed in diverse networking environments. With an industry-wide compatibility and strict test program, FS 10G SFP+ modules can give customers a wide variety of 10 Gigabit Ethernet connectivity options such as server/storage to switch connectivity.

Conclusion

Different 10G SFP+ cables are selected for different distance and application. Generally speaking, 10G DAC is perfect for short reach applications within racks, while AOCs are suitable for inter-racks connections between ToR and EoR switches. With excellent quality and lifetime warranty, FS 10G optics brings real-time network intelligence to the financial services market at 10 Gbps speeds. All the products mentioned in the previous text are in stock. For more information, please visit us at www.fs.com.

25G SFP28 Cable: The Most Economical Option for ToR Server Connection

25 Gigabit Ethernet is proposed standard for Ethernet connectivity in a data center environment, developed by IEEE 802.3 task force P802.3by. The IEEE 802.3bj standard then uses technology defined for 100 Gigabit Ethernet implemented as four 25-Gbit/s lanes. These standards define:

  • a single-lane 25 Gbit/s 25GBASE-KR PHY for printed circuit backplanes
  • a single-lane 25 Gbit/s 25GBASE-CR-S PHY for 3 m twin-ax cables (in-rack)
  • a single-lane 25 Gbit/s 25GBASE-CR-L PHY for 5 m twin-ax cables (inter-rack)
  • a single-lane 25 Gbit/s 25GBASE-SR PHY for 100 m OM4 or 70 m OM3 multi-mode optical fiber

What’s 25G SFP28 Cable?
According to the above standards, the IEEE CFI is now focused on the SFP28 and QSFP28 direct attach copper twin-ax cables (DACs). SFP28 DAC refers to the 25G DAC cable using the SFP+ form factor, and QSFP28 DAC refers to the 100G DAC cable using the QSFP+ form factor. The maximum transmission distance of these cables is 5 meters.

There are two SFP28 DAC cable types: 25G SFP28 to SFP28 DAC and 100G QSFP28 to four SFP28 breakout DAC. The SFP28 to SFP28 passive copper cable is a high speed, cost-effective 25Gbp/s Ethernet connectivity solution designed to meet the growing needs for higher bandwidth in data centers. The QSFP28 to four SFP28 breakout DAC is used to connect 100G switches to four 25 Gigabit in cabinet or adjacent cabinet servers. Compared to 40G using four 10G lanes and 100G using 10 10G lanes, the 25G SFP28 DAC provides the low-cost copper server connection for Top of Rack (ToR) switches.

To more directly illustrate effectiveness of SFP28 to SFP28 DAC cable and QSFP28 to four SFP28 breakout DAC cable, let’s see a series of pictures displayed below:

Existing 10G Topology
Today’s volume topology for web-scale data centers

  • 48 servers/ToR
  • 3:1 oversubscription
  • Uses low-cost, thin 4-wire SFP+ DAC cable

sfp+ to sfp+ DAC

40G Topology
High-performance, low volume topology

  • Uses bulkier 16-wire QSFP+ DAC cable
  • Max. 24 servers/ToR with 3:1 oversubscription
  • Will transition to 100G

qsfp+ to qsfp+ dac

25G Direct Connect
Same topology as 10G

  • 48 servers/ToR
  • 3:1 oversubscription w/ 100G uplinks, non-blocking w/ 400G
  • Uses 4-wire SFP28 DAC cable

sfp28 to sfp28 dac

Existing 4x10G Topology
Commonly used topology in web-scale data centers

  • Permits non-blocking 10G mesh
  • 40G ports used as 4x10G with QSFP+ to SFP+ breakout cable
  • Same server network interface card (NIC) as 10G

qsfp+ to 4 sfp+ dac

4x25G Breakout
Same topology as 4x10G

  • Permits non-blocking 25G mesh
  • 100G ports used as 4x25G with QSFP28 to SFP28 break-out cable
  • Same server network interface card (NIC) as 25G direct connect

qsfp28 to 4 sfp28 dac

High Density 25G
Increased port switch port density

  • 64 servers in non-blocking architecture
  • 96 servers in a 3:1 oversubscription
  • 24-port 400G ToR
  • 192 servers in non-blocking architecture

100G qsfp28 to 4 sfp28 dac