Month: September 2016

10GBASE-CR or 10GBASE-T for 10G Copper Network?

As is known to all, fiber optic cables are widely deployed in telecommunication networks. It seems that copper cables are out of date. However, copper network is superior to fiber network in some cases as copper cables are stronger and easier to manage than fiber cables. Copper cable also takes the advantage of lower cost than fiber. Besides, copper network is easier to build, which eliminates the process of I/O. Today’s copper cables are able to support data rate of 1G, 10G, 40G and even 100G, among which 10G copper based network is most commonly deployed. Currently, there are two types of standards designed for 10G copper-based network: 10GBASE-CR and 10GBASE-T. Which one is more suitable for you when building a 10G copper based network? This following part will give you the answer.


Comparison Between 10GBASE-CR and 10GBASE-T

When choosing between the 10GBASE-T and 10GBASE-CR, several critical factors should be considered which are area transmission distance, transmission media, module type and cost.

  • Transmission Distance and Media

10GBASE-CR is invented before 10GBASE-T. 10GBASE-CR can support 10G data rate up to 10 meters over twinax copper cable. While 10GBASE-T can support a longer transmission up to 100 meters over Cat6a twisted copper pair.

  • Transmission Interfaces

Small package form factors are adopted in both 10GBASE-CR and 10GBASE-T applications, to meet the requirement of high density. SFP+ form factor is most commonly used for 10GBASE-CR applications.

SFP+ passive direct attach cables and SFP+ active direct attach cables are usually used for 10GBASE-CR applications. The SFP+ cable is terminated with a SFP+ module on each end. 10G SFP+ active direct attach twinax copper cable can reach a longer transmission distance than the passive one. The market now can provide a wide selection of SFP+ DACs for different types of switches and platform.


Network interface card with SFP+/XFP interfaces are often used for 10GBASE-T applications. Not all the vendors provide 10GBASE-T SFP+ modules. HP has provided a 10GBASE-T SFP+ module. However, compatibility of the modules is limited by the switch brand. This HP 10GBASE-T SFP+ module can only be used on HP switches. Thus, 10GBASE-T application is sort of limited for now.

  • Cost

Put transmission distance aside, the cost for 10GBASE-CR cabling is much lower for 10GBASE-T cabling. For instance, a HP 10GBASE-T SFP+ costs around $ 1000 USD. However, the price for a 10G HP SFP+ DAC is around $100 USD. This price is lower to $ 23 for a 1.2 meter HP JD096C compatible passive SFP+ DAC in FS.COM. Thus, 10GBASE-CR cost less than 10GBASE-T in general.


In general, 10GBASE-T has the biggest advantages of achieving transmission distances of up to 100m over Cat6a cable. 10GBASE-CR can only reach up to 15 meters over twinax copper cable but with the advantages of lower cable costs. Since most of our data center use for copper cabling are less than 15 meters, it means that 10GABSE-CR can satisfy a wider spectrum of demands for copper cabling in data centers. Therefore, 10GABSE-CR is preferred for most 10G copper cabling cases.


1000BASE-SX SFP Modules Provided by FS.COM

Introduction to Gigabit Ethernet

In order to accelerate speeds from 100 Mbps Fast Ethernet up to 1 Gbps, many changes have been made to the physical interfaces. Gigabit Ethernet uses the same 802.3 frame format as 10Mbps and 100Mbps Ethernet systems. It runs ten times faster than the speed of Fast Ethernet, backward compatibility is assured with earlier versions, increasing its attractiveness by offering a high bandwidth connectivity system to the Ethernet family of devices.

Defined by IEEE 802.3z standard, Gigabit Ethernet originally launched three different physical layers: 1000Base-LX and 1000Base-SX using fiber and 1000Base-CX using copper. These physical layers were originally developed by IBM for the ANSI Fibre Channel systems and used 8B/10B encoding to reduce the bandwidth required to send high-speed signals. The IEEE merged the fibre channel to the Ethernet MAC using a gigabit media independent interface (GMII), which defines an electrical interface, enabling existing fibre channel PHY chips to be used and enabling future physical layers to be easily added.

1000Base-SX for Horizontal Fiber

1000Base-SX is a physical layer specification for Gigabit Ethernet over fiber optic cabling as defined in IEEE 802.3z. SX stands for short wavelength. And 1000Base-SX uses short wavelength laser (850nm) over multimode fiber as opposed to 1000Base-LX, which uses long wavelength laser over both multimode and single-mode fiber. The maximum distance of (multimode) fiber, based on 1000Base SX is 550m.

This Gigabit Ethernet version was developed for the short backbone connections of the horizontal network wiring. The SX systems operate full-duplex with multimode fiber only, using the cheaper 850nm wavelength laser diodes. The maximum distance supported varies between 200 and 550 meters depending on the bandwidth and attenuation of the fiber optic cable used. The standard 1000Base-SX NICs available today are full-duplex and incorporate LC fiber connectors.

1000BASE-SX SFP Optical Module Selection Guide

SFP transceiver is a hot-swappable input/output device that plugs into a Gigabit Ethernet port/slot, linking the port with the fiber-optic network. SFP can be used and interchanged on a wide variety of Cisco products and can be intermixed in combinations of IEEE 802.3z compliant 1000Base-SX interfaces on a port-by-port basis. 1000BASE-SX SFP (eg. Cisco GLC-SX-MM) supports link length of up to 550m on multimode fiber at 1Gbps. This optic works at 850nm wavelength and uses a LC connector.

SFP modules have now become an indispensable component in networks. Thus, it is very necessary to use quality assured modules. If you want to purchase cheaper and 100% compatible 1000Base-SX SFP modules online, FS.COM may be your good choice. You would not worry about the compatibility of the optics you have bought here. Because there is a perfect system from the production to shipment. Compatible SFP transceiver modules offered by FS.COM are test-assured and fully compatible with major brands (such as Cisco, HP, NETGEAR, Finisar, Juniper, etc.) and supported by a lifetime warranty. Besides, all these SFP modules can be customized according to your specific requirements.