Tag Archives: QSFP+ copper DACs

The Basics of Dirrect Attach Cables

Dirrect attach cable (DAC), is a cost effective and proven solution for interconnecting networking applications. It can provide inexpensive and reliable connections using either copper cables or fiber cables. What is DAC? How copper DAC and fiber DAC differ from each other? Here is what you need to know about DACs.

DAC Definition

A direct attach cable is a fixed assembly that is purchased at a given length, with the connector modules permanently terminated to each end of the cable to connect switches to routers or servers. DACs are much cheaper than the regular optics, since the “transceivers” on both ends of DACs are not real optics and their components are without optical lasers. They are preferable choice for their low cost, low power consumption and high performances. DAC are made of the two kinds of cable materials: copper and optical fiber. They are respectively called direct attach copper cable and active optical cable.

DAC Assemblies—Copper

Direct attach copper cable is interchangeable and hot swappable with fiber optic modules. It is designed in either active or passive versions. It supports such multiple protocols as Gigabit & 10G Ethernet, 8G FC, FCoE and InfiniBand. Direct attach copper cable is a cost effective solution over optical transceivers and and cables for short reach applications. It can support higher data rates than traditional copper interfaces—from 4Gbps to 10Gbps per channel. The defect of direct attach copper cable is that it is heavy and bulky, making it difficult to be managed. Furthermore, due to the nature of electrical signals, direct attach copper cable is vulnerable to the effects of electromagnetic interference (EMI), such as undesirable responses, degradation, or complete system failure. Fiberstore offers various QSFP+ direct attach copper cables with different lengths for your 40G applications. For example, lengths of Juniper EX-QSFP-40GE-DAC-50CM, QFX-QSFP-DAC-1M and QFX-QSFP-DAC-3M compatible QSFP+ to QSFP+ passive copper cables are respectively 0.5m, 1m, and 3m.

0.5m Juniper EX-QSFP-40GE-DAC-50CM Compatible QSFP+ to QSFP+ Passive Copper Cable

DAC Assemblies—Fiber

Active optical cable (AOC) is an alternative to optical transceivers, eliminating the separable interface between transceiver module and optical cable. It meets Small Form-factor (SFF) standards. Compaired to direct attach copper cable, AOC weighs less and can support longer transmission distance. It is immune to electromagnetic energy since the optical fiber is dielectric (not able to conduct electric current). What’s more, it is an alternative to optical transceivers and it can eliminate the separable interface between transceiver module and optical cable. AOC has no EMI. However, it costs more than copper cable.

Active_Optical_Cables

Applications of DAC

Direct attach cables are widely applied in storage area network, data center, and high-performance computing connectivity. They suppoet high speed I/O applications in storage, networking and telecom markets. And they can also be sused in witches, servers, routers, network interface cards (NICs), and Host Bus Adapters (HBAs). There are many different kinds of DACs, they all have their specific applicayions. For example, 40G AOC is commonly used for short-range multi-lane data communication and interconnect applications.

Conclusion

Fiberstore offers a variety of high speed interconnect DAC assemblies including 10G SFP+ cables, 40G QSFP+ cables, and 120G CXP cables to satisfy the demands from 10G to 100G interconnection. Direct attach cables provided by Fiberstore can be customized to meet different requirements. And we also offer all kinds of high quality QSFP+ modules branded by many famous companies, like Brocade QSFP+, Dell QSFP+, Juniper QSFP+, Finisar QSFP+, Intel QSFP+, etc. You can buy from us with confidence.

Cisco 40GBASE QSFP+ Modules

Cisco 40GBASE QSFP+ (quad small form-factor pluggable plus) modules offer customers a wide variety of high-density and low-power 40 Gigabit Ethernet connectivity options for data center, high-performance computing networks, enterprise core and distribution layers, and service provider transport applications. In this post, several different kinds of conectivity options provided by Cisco will be introduced.

Features and Benefits of Cisco 40GBASE QSFP+ Module

Main features of Cisco 40GBASE QSFP+ modules include:

  • Interoperable with other IEEE-compliant 40GBASE interfaces
  • Hot-swappable input/output device that plugs into a 40 Gigabit Ethernet QSFP+ Cisco switch port
  • High-speed electrical interface compliant to the IEEE 802.3ba standard
  • Compliant to SFF 8436 and QSFP Multisource Agreement (MSA)
Cisco QSFP-40G-SR4-S

Cisco 40GBASE-SR4 QSFP+ module supports link lengths of 100m and 150m respectively on laseroptimized OM3 and OM4 multimode fiber cables. It primarily enables high-bandwidth 40G optical links over 12-fiber ribbon r cables terminated with MPO/MTP multi-fiber connectors. It can also be used in 4x10G mode along with ribbon to duplex fiber breakout cables for connectivity to four 10GBASE-SR optical interfaces. Cisco QSFP-40G-SR4-S is optimized to guarantee interoperability with any IEEE-compliant 40GBase-SR4 module.

Cisco QSFP-40G-CSR4

Cisco 40GBASE-CSR4 QSFP+ module extends the reach of the IEEE 40GBASE-SR4 interface to 300m and 400m respectively on laser-optimized OM3 and OM4 multimode fiber cables. Each 10-gigabit lane of this module is compliant to IEEE 10GBASE-SR specifications. This module can be used for native 40G optical links over 12-fiber ribbon cables with MPO/MTP connectors, or in a 4x10G mode with ribbon to duplex fiber breakout cables for connectivity to four 10GBASE-SR interfaces. The following picture shows a Cisco QSFP-40G-SR4-S QSFP+ module and a Cisco QSFP-40G-CSR4 QSFP+ module.

QSFP-40G-SR4-S QSFP+ and QSFP-40G-CSR4 QSFP+

Cisco QSFP-40G-LR4-S

Cisco 40GBASE-LR4 QSFP module supports link lengths of up to 10 km over a standard pair of G.652 single-mode fiber with duplex LC connectors. QSFP-40G-LR4-S module supports 40GBase Ethernet rate only. 40 Gigabit Ethernet signal is carried over four wavelengths. Multiplexing and demultiplexing of the four wavelengths are managed in the device. QSFP-40G-LR4-S does not support FCoE.

Cisco WSP-Q40GLR4L

Cisco WSP-Q40GLR4L QSFP+ module supports link lengths of up to 2 km over a standard pair of G.652 single-mode fiber (SMF) with duplex LC connectors. 40 Gigabit Ethernet signal is carried over four wavelengths. It is interoperable with 40GBase-LR4 for distances up to 2 kilometers. The following picture shows a Cisco QSFP-40G-LR4-S QSFP+ module and a Cisco WSP-Q40GLR4L QSFP+ module.

QSFP-40G-LR4-S QSFP+ and WSP-Q40GLR4L QSFP+

Cisco QSFP+ Copper Direct Attach Cables (DACs)

Cisco QSFP+ copper DACs include QSFP+ to QSFP+ copper DACs and QSFP+ to 4SFP+ copper DACs. Cisco QSFP+ copper DACs are suitable for very short distances and offer a very cost-effective way to establish a 40-gigabit link between QSFP+ ports of Cisco switches within racks and across adjacent racks. QSFP+ to 4SFP+ copper breakout DACs cables connect to a 40G QSFP+ port of a Cisco switch on one end and to four 10G SFP+ ports of a Cisco switch on the other end.

Cisco QSFP+ Active Optical Cables (AOCs)

Cisco QSFP+ AOCs include QSFP+ to QSFP+ AOCs and QSFP+ to 4SFP+ AOCs. Active optical cables are much thinner and lighter than copper cables, which makes cabling easier. Active optical cables enable efficient system airflow and have no electromagnetic interference (EMI) issues, which is critical in high-density racks.

Fiberstore is a professional manufacturer and supplier for optical fiber products and provides various kinds of 40GBase QSFP+ transceivers branded by many famous companies. Cisco QSFP+ transceivers offered by Fiberstore are the most cost-effective standards-based QSFP+ modules fully compatible with Cisco switches and routers. They are 100% compatible with major brands and backed by a lifetime warranty.