Overview of SFP+ Direct Attach Copper Cable

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.

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 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.

How Much Do You Know About SFP+ Direct Attach Cable?

Today, more bandwidth is needed to support the use of server virtualization, and the amount of data that needs to be transmitted to and from storage area networks (SANs) has also dramatically increased. To accommodate the fast growing number of operating systems and applications and data transmission between servers and switches, SFP+ direct attach cable (DAC), has been a preferable solution for it can provide a lower-power means for operation on short fiber optic links or short copper connections. How much do you know about SFP+ direct attach cable?

What Is SFP+ Direct Attach Cable?

First, we need to know what SFP+ direct attach cable is. It is a fixed assembly that is purchased at a given length, with SFP+ connector modules permanently attached to each end of the cable. SFP+ direct attach cable uses an enhanced SFP+ connector to transmit and receive 10Gbps data through one paired transmitters and receivers over a thin twinax cable or a fiber optic cable. It provides high performance in 10 Gigabit Ethernet network applications. 10G SFP+ direct attach cable is designed to use the same port as an optical transceiver, but compared with optical transceivers, the connector modules attached to the cable leave out the expensive optical lasers and other electronic components, thus achieving significant cost savings and power savings in short reach applications.

Advantages of SFP+ Direct Attach Cable

SFP+ direct attach cable is a low cost, low power consumption and low latency solution that is ideal for high-density, in-rack 10Gbps connections between servers and switches. It provides better cable management for high-density deployments and enhanced electrical characteristics for the most reliable signal transmission. Here are several outstanding advantages of SFP+ direct attach cables.

• MSA compliant—fully conform to the SFP+ MSA specifications
• High speed—support 10 Gbps data rates with backwards compatibility to 1 Gbps
• Reliability—RoHS compliant with excellent EMI performance and high reliability
• Scalability and flexibility—provide enhanced scalability and flexibility, and higher density for today’s data centers and storage area networks
• Space saving—offer the smallest 10 gigabit form factor and a small overall cable diameter for higher density and optimized rack space in 10G Ethernet uplinks and Fibre Channel
• Cost saving—cost up to three times less than fiber optic solutions, while offering lower latency and consuming up to 50% less power per port than current copper twisted-pair cabling systems

Types of SFP+ Direct Attach Cable

Generally speaking, SFP+ direct attach cable can be divided into SFP+ direct attach copper cables and SFP+ active optical cables (AOCs). This part will discuss these two kinds of SFP+ direct attach cables.

There are two types of SFP+ direct attach copper cables, SFP+ active copper cable (ACC) and SFP+ passive copper cable (PCC). SFP+ passive copper cable (PCC), or passive SFP+ DAC, is fully compliant to the SFF-8431 SFP+ MSA. It has no signal amplification in the cable assembly. When it is utilized, electronic dispersion compensation (EDC) is typically used on the host board designs. EDC allows for an extended length of passive cable assemblies. They deliver high-speed connectivity between active equipment with SFP+ ports. The copper cable trunks are made to order, reducing installation time and maximizing flexibility. The low power consumption assists in making the passive copper cable assembly an economic solution for within rack or rack to rack applications. SFP+ active copper cable (ACC) has signal amplification and equalization in the cable assembly. SFP+ ACC assemblies are typically used in host systems that do not employ EDC. They also incorporate Rx LOS and Tx Disable features. As with passive cables, the industry standard EEPROM signature enables the host system to differentiate between an active copper cable and a fiber optic transceiver. The picture below shows an HP JG081C compatible 10G SFP+ passive direct attach copper cable.

SFP+ active optical cable is composed of SFP+ optical transceivers in both ends and fiber optic cable in between. This integrated optical module solution removes the complicated optical fiber interface and brings friendly electrical-to-electrical interface to users. SFP+ AOC accepts the same electrical inputs as a traditional copper cable. It uses optical fiber and electrical-optical conversion on the cable ends to improve speed and data transmission distance of the cable while not sacrificing compatibility with standard electrical interfaces. SFP+ AOC is designed to meet the requirements of high speed, high density and low power consumption for applications in today’s data centers via optical fiber wire. It has been a preferable interconnect solution for SFP+ applications. SFP+ AOC is compliant to industrial standard SFP MSA and provides high performance SFP+ interfaces, supporting 10Gb/s bi-directional operation. The image below shows a Cisco SFP-10G-AOC10M compatible 10G SFP+ active optical cable.

Conclusion

SFP+ direct attach cable can provide you with a cost-effective and low power consumption solution for your high-density 10 Gigabit applications. It has a lot of advantages. These three kinds of 10G SFP+ direct attach cable assemblies, 10G SFP+ passive copper cable (PCC), 10G SFP+ active copper cable (ACC), and 10G SFP+ active optical cable (AOC) are of their special applications. SFP+ direct attach cable now has been a very popular choice in the market.