The document provides an overview of SFP+ Direct Attach Copper Cables, highlighting their cost-effectiveness and suitability for short-distance 10G Ethernet applications. It details the two types of SFP+ cables—active and passive—and their applications in data center infrastructure. Additionally, it addresses FAQs regarding their performance, cable specifications, and customization options available through Fiberstore.

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Fiberstore White Paper | Overview of SFP+ Direct Attach Copper Cable 1
SFP+ direct attach copper cable assembly is a high speed and cost-effective alternative to fiber optic
cables in 10G Ethernet applications. 10g copper SFP is suitable for short distances, and ideal for
highly cost-effective networking connectivity within a rack and between adjacent racks. It enables
hardware OEMs and data center operators to achieve high port density and configurability at a low
cost and reduced power requirement. SFP+ direct attach copper cable has been a good solution.
This post will provide you with some basic information about SFP+ direct attach copper cable.
Introduction
SFP+ direct attach copper cable, also known as twinax cable, is an SFP+ cable assembly used in rack
connections between servers and switches. It consists of a high speed copper cable and two SFP+
copper modules. SFP+ copper modules allow hardware manufactures to achieve high port density,
configurability and utilization at a very low cost and reduced power budget. SFP+ copper cable
assemblies meet the industry MSA for signal integrity performance. The cables are hot-removable
and hot-insertable, which means that you can remove and replace them without powering off the
switch or disrupting switch functions. A cable comprises a low-voltage cable assembly that connects
directly into two SFP+ ports, one at each end of the cable. The cables use high-performance
integrated duplex serial data links for bidirectional communication and are designed for data rates
of up to 10 Gbps. The following picture shows a Cisco SFP-H10GB-ACU7M compatible 10G SFP+
direct attach copper twinax cable.
Overview of SFP+ Direct
Attach Copper Cable

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Types of SFP+ Direct Attach Copper Cables
Generally, SFP+ direct attach copper cable assemblies have two types, SFP+ active direct attach
copper cable and SFP+ passive direct attach copper cable.
SFP+ Active Copper Cable: SFP+ active direct attach copper cable assemblies contain low power
circuitry in the connector to boost the signal and are driven from the port without additional power
requirements. The active version provides a low cost alternative to optical transceivers, and are
generally used for end of row or middle of row data center architectures for interconnect distances
of up to 15 meters..
SFP+ Passive Copper Cable: SFP+ passive direct attach copper cable assemblies offer high-speed
connectivity between active equipment with SFP+ ports. The passive assemblies are compatible
with hubs, switches, routers, servers, and network interface cards (NICs) from leading electronics
manufacturers like Cisco, Juniper, etc.
Applications of SFP+ Direct Attach Copper Cables
 Serial data transmission
 Network Interface Cards (NICs)
 Data center cabling infrastructure
 Fibre Channel over Ethernet: 1, 2, 4 and 8G
 10Gb Ethernet and Gigabit Ethernet (IEEE802.3ae)
 High density connections between networking equipment
 High capacity I/O in storage area networks, and storage servers
 InfiniBand standard SDR (2.5Gbps), DDR (5Gbps) and QDR (10Gbps)
 Switched fabric I/O such as ultra high bandwidth switches and routers
FAQs of SFP+ Direct Attach Copper Cables
1. Whether active or passive cable assemblies are required?
Active cable assemblies have signal amplification and equalization built into the assembly. They are
typically used in host systems that do not employ EDC. Passive cables have no signal amplification in
the assembly and rely on host system Electronic Dispersion Compensation (EDC) for signal
amplification/equalization.
2. What are the performance requirements for the cable assembly?
Both SFP+ active and passive copper cable assemblies should meet the signal integrity requirements
defined by the industry MSA SFF-8431.
3. What cable length and wire gauge are required?
Cable length and wire gauge are related to the performance characteristics of the cable assembly.
Longer cable lengths require heavier wire gauge, while shorter cable lengths can utilize a smaller
gauge cable. Smaller wire gauges results in reduced weight, improved airflow and a more flexible

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Fiberstore White Paper | Overview of SFP+ Direct Attach Copper Cable 3
cable for ease of routing.
4. Are there any special customer requirements?
Examples of special customer requirements include: custom cable lengths, EEPROM programming,
labeling and packaging, pull tab length and color, company logo, signal output de-emphasis, and
signal output amplitude. You can order custom cables to your specific system architecture.
Conclusion
Fiberstore SFP+ twinax copper cables are available with custom version and brand compatible
versions. All of them are 100% compatible with major brands like Cisco, HP, Juniper, Enterasys,
Extreme, H3C and so on. Both passive twinax cables in lengths of 1, 3 and 5 meters, and active
twinax cables in lengths of 7 and 10 meters are available. And the lengths can be customized up to
the your requirements. You can get high quality compatible SFP+ cables and worldwide delivery
from Fiberstore.

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Fiberstore White Paper | Overview of SFP+ Direct Attach Copper Cable 4
Contact Us
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Technology Park, No.6, Keyuan Road,
Nanshan District, Shenzhen 518057,
China
Tel: +86 (755) 8300 3611
Fax: +86 (755) 8326 9395
Email: sales@fiberstore.com
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HongKong
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Email: sales@fiberstore.com
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WA 98188,United States
Tel: +1-425-226-2035
Fax: +1-253-246-7881
Email: sales@fiberstore.com
London Office (United Kingdom)
Third Floor 207 Regent Street, London,
W1B 3HH, United Kingdom
Tel: +44 2081441980
Notice: This document is for informational purposes only and does not set forth any warranty, expressed or
implied, concerning any equipment, equipment features, or service offered or to be offered by Fiberstore.
Fiberstore reserves the right to make changes to this document at any time, without notice, and assumes no
responsibility for its use. This information document describes features that may not be currently available.
Contact a Fiberstore sales team for information on feature and product availability.
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