In the past decades, the telecommunication industry has changed a lot. A wide selection of transmission methods has been introduced. Fiber optic cables are widely used in today’s network. It seems that copper cables are out of fashion. However, there are still many advantages of using copper networks. Copper cables are stronger and easier to manage than fiber optic cables. The cost of copper cable is much lower than fiber optic cables. In addition, copper network is easier to build, which eliminating the process of I/O. Now, 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 which are designed for 10G copper based network: 10GBASE-CR and 10GBASE-T. Which one should you choose if you want to build a 10G copper based network? This article offers the answer.
Several significant factors should be considered during the selection between the 10GBASE-T and 10GBASE-CR, which area transmission distance, transmission media, module type and cost.
10GBASE-CR and 10GBASE-T Transmission Distance and Media
10GBASE-CR is invented before 10GBASE-T. 10GBASE-CR can support 10G data rate up to 10 meters over twinax cable. While 10GBASE-T can support a longer transmission up to 100 meters over Cat6a twisted copper pair.
10GBASE-CR and 10GBASE-T 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 two SFP+ copper cables are 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 kind of limited for now.
10GBASE-CR and 10GBASE-T Cabling 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.
Generally, 10GBASE-T has the greatest advantages on transmission distances (up to 100m over Cat6a). Although, 10GBASE-CR can only reach up to 15 meters over twinax copper cable. It has great advantages on cable costs. In addition, most of our data center use for copper cabling are less than 15 meters, which means 10GABSE-CR can satisfy most requirement for copper cabling in data centers. Thus, 10GABSE-CR is suggested for most 10G copper cabling cases.