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All You Need to Know about 56G QSFP+ to QSFP+ DAC Twinax Cable

DAC is the short name for direct attach cable. Currently, there are many different types of DAC twinax cables on the market such as SFP+ DAC Cable and QSFP DAC Cable. Terminated with transceiver-style connectors, they are designed to be used in the same ports as a typical SFP+ or QSFP transceiver, with no need for adaptors or converters, replacing two optical modules and a connectorized optical fiber with a twinax copper cable assembly. Here in this post, we will mainly focus on 56G QSFP+ to QSFP+ DAC Twinax Cable.

Basics on 56G QSFP+ to QSFP+ DAC Twinax Cable

The 56G QSFP+ to QSFP+ DAC twinax cable, as implied in the name, uses QSFP+ MSA and by using the inexpensive copper twinax cable with QSFP+ connectors on both sides, and provides 56 Gigabit Ethernet connectivity between devices with QSFP+ interfaces，which is suitable for very short distances and offers a highly cost-effective way to establish a 56 Gigabit link connectivity. Unlike 40G (10Gx4) QSFP+ DAC twinax cable, a kind of 40gb ethernet cable, the 56G QSFP+ DAC twinax cable is designed for 56G (14Gx4) InfiniBand FDR interconnecting networking applications such as high-performance computing (HPC), enterprise networking including top-of-rack switching and network storage markets.

56G QSFP+DAC

The 56G QSFP+ DAC twinax cable is fully comply with QSFP+ Multi-Source Agreement (MSA) standards SFF-8436 and InfiniBand FDR specifications. And it is developed specifically as a cost-effective and lower-power alternative to 56G QSFP+ optics and 56G QSFP+ active optical fiber cable (QSFP+ AOC).

Specification and Features of 56G QSFP+ to QSFP+ DAC Twinax Cable

Now, many suppliers can provide 56G QSFP+ DAC twinax cable for customers. The key features and specification for these products are more ore less the same. Here, we take the generic compatible 56G QSFP+ DAC cable from FS for example.

Specification

specification for 56g dac

Key Features

  • Lower cost than 56G QSFP+ optics and active optical cable (AOC)
  • Maximum aggregate data rate: 56 Gb/s (4 x 14Gb/s)
  • Compliant with Infiniband QDR/DDR/FDR data rates
  • Hot-pluggable QSFP+ 38-PIN footprint
  • Low Insertion Loss and power consumption
  • Operating temperature range: 0 to 70°C

Summary

56G QSFP+ to QSFP+ DAC twinax cables are passive optic cables designed with high performance, low power consumption, long reach interconnect solution supporting 56G Ethernet. For suppliers like FS, their 56G QSFP+ to QSFP+ DAC and other twinax cable offer compatibility with a huge range of vendors, enabling the connectivity customers need within the Top of Rack and End of Row environments.

Datasheet of 40G QSFP Module

When it comes to selecting 40G QSFP modules, customers may be dazzled by the various products provided by various suppliers. Some of them may directly purchase from big brands like Cisco. Actually, except for those well known brands, many other rising companies like FS also provide 40G QSFP module, which usually come at a much lower price with with a high quality. This post will demonstrate the 40G QSFP Datasheet provided by FS.

40G QSFP Module Datasheet: QSFP 40G SR4 Datasheet

The S-Class FS 40GBASE-SR4 QSFP module supports link lengths of 100 and 150 meters, respectively, on laser-optimized OM3 and OM4 multimode fibers. QSFP 40G SR4 transceiver is aligned to IEEE 40GBASE-SR4 optical specifications which support high-bandwidth 40G optical links over 12-fiber parallel fiber terminated with MPO/MTP multifiber female connectors. Because IEEE 40GBASE-SR4 does not support 4x10G breakout connectivity to 10GBASE-SR, see QSFP-40G-SR4 or QSFP-40G-CSR4 for such applications. QSFP 40G SR4 does not support FCoE. More specific details of FS QSFP 40G SR4 can be obtained in the table below.

qsfp module- qsfp 40g sr4 datasheet

40G QSFP Module Datasheet: QSFP 40G LR4 S Datasheet

The FS 40GBASE-LR4 QSFP module supports link lengths of up to 10 kilometer over a standard pair of G.652 SMF (single-mode fiber) with duplex LC connectors. The QSFP-40G-LR4-S module supports 40GBASE Ethernet rate only. The 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. More information have been shown in the following QSFP 40g LR4 S.

qsfp module-qsfp 40g lr4 datasheet

QSFP+ SR4 vs QSFP+ LR4: Which One to Choose?

After going through QSFP 40G SR4 Datasheet and QSFP 40g LR4 S Datasheet, you may have had a basic understanding of QSFP 40G SR4 and QSFP 40g LR4. SR is short for short reach and LR represents Long Reach. The most obvious difference is that 40GBASE-SR4 is with MPO/MTP port while the 40GBASE-LR4 is with the Duplex LC port. The cost of 40GBASE-SR4 QSFP+ is more cheaper than the 40GBASE-LR4 QSFP+. Additionally, the fiber cost of the cabling with them also have a big difference. Because SMF cabling is more expensive than the MMF cabling.

Summary

As speeds have increased to 40G, the quad small form-factor pluggable (QSFP) has become the high-density transceiver of choice. Hoping this post on FS 40G QSFP Datasheet may help you when selecting 40G optical transceivers.

Related articles:

40G QSFP+ LR4 Transceiver—An Ideal Choice for 40G Network

Three Types of 40G QSFP+ Transceivers for Long Distance Transmission

Transceiver Solutions for Migrating to 40G Network

40G QSFP+ LR4 Transceiver—An Ideal Choice for 40G Network