With the broad adoption of network function virtualization (NFV) and unified data and storage networking toady, servers are now seeing increased I/O demands. To keep pace with the increased I/O demand, network access line rates have migrated from 1Gb/s to 10Gb/s. Several connectivity solutions exist to service these network access needs including direct attach cables (DAC), optical transceiver modules and embedded 10GBASE-T RJ45 ports. Each comes with its own set of distinct advantages and disadvantages, but only the new 10GBASE-T SFP+ transceiver offers the potential to deliver power saving connectivity by utilizing Cat 6a/7 cable infrastructure with pay-as-you-grow flexibility.
The 10GBASE-T SFP+ copper transceiver is specifically designed for high speed communication links that require 10 Gigabit Ethernet over Cat 6a/7 cable with a link limit of 30 m. It is the first SFP+ transceiver that offers 10Gb/s communication over copper cables. In addition, this copper transceiver is compliant with SFF-8431 and SFF-8432 MSA. The power usage and heat generated for 10GBASE-T is 4-8 watts, but 10GBASE-T SFP+ copper transceiver consumes 2.5 watts. Obviously, the specification of SFP+ copper module has been optimized to save more than 0.5 W per port when compared to an embedded 10GBASE-T RJ45 port for link distances up to 30m. These power savings can add-up in ToR, mid-row and end-of-row switch connectivity. Implemented as an SFP+ form factor, the new 10GBASE-T transceiver is a power optimized solution for lengths up to 30m.
SFP+ DAC, SFP+ optical transceiver and 10GBASE-T SFP+ copper transceiver are three common components used in 10G connections. Here will compare the 10GBASE-T SFP+ copper transceiver with SFP+ DAC and SFP+ optical transceiver, in order to get further understanding of 10GBASE-T SFP+ copper transceiver.
As mentioned above, the maximum linking distance of 10GBASE-T SFP+ module is 30m, while the SFP+ DAC is up to 7m. Furthermore, SFP+ 10GBASE-T module has reduced the power consumption of 10G copper modules, which is a great news for the heavy-loaded 10G data center networks. SFP+ DAC has significantly lower overall cost when you include switch, NIC and cable, however 10GBase-T has more flexibility and can reach longer distance. For data centers, the advantages of SFP+ DAC are a very good match for today’ s requirements and emerging trends. That’s why SFP+ DAC is being adopted rapidly as best practice for new data centers. For wiring closets, 10GBase-T will be the obvious choice once the demand for bandwidth becomes more acute and once the price and power for 10GBase-T technology comes down.
Both of the SFP+ copper and fiber modules are hot-pluggable with a managed soft-start and are interoperable with any SFP+ cage and connector system. However, they have total different performance when plugging into the 10G switches. SFP+ 10GBASE-T module uses the Cat6a cables for a link length of 30 m over RJ45 connectors. SFP+ SR operates over OM3 cables with a distance of 300m over LC connectors, while SFP+ LR optics utilizes the OS2 LC duplex cables for a distance of 10 km. Short wavelength (850nm) optical transceiver modules can be used for lengths up to 300m at 10Gb/s data rates. In comparison, multi-mode fiber cabling is considerably more expensive than Cat 6a UTP and the solution overall is not well suited for cost sensitive network edge applications. Field termination of fiber requires special skill sets and tools which significantly increase the complexity and cost of installation.
From what we have discussed, we can see that the power consumption of 10GBASE-T SFP+ Copper Module is higher than SFP+ DACs and SFP+ optical transceivers. And its price is also higher than the other two components. But with the available cheap SFP+ DAC and reliable SFP+ fiber optics available for 10Gbps application, why should people use the SFP+ copper modules?
Firstly, in data centers like the enterprise system, the length of the vast majority of links lies between 10 meters and 100 meters. The 10GBASE-T SFP+ copper transceiver which provides 10Gb/s of data transmission over distance of 30 meters implements the limitation of SFP+ DAC. Secondly, with the common RJ-45 connector, 10GBASE-T SFP+ copper transceiver has the benefits over SFP+ solutions. Because copper-based infrastructure is far less expensive than fiber optics. Thirdly, 10GBASE-T SFP+ copper transceiver is convenient for operators to deploy their network systems. When connecting 10G modules to copper networks, 10GBASE-T SFP+ copper transceiver can be directly added into the copper networks, while the 10G SFP+ transceiver needs to connect with Ethernet switch or media converter to realize this connection.
It is true that Cat 6a/7 cabling can provide limited support of 10GBASE-T in some environments, but the reality is that there are several compelling reasons to specify SFP+ 10GBASE-T copper modules in a new 10 Gbps-ready data center:
10GBASE-T SFP+ Copper Transceiver Application Scenario
As it has been mentioned before, 10G SFP+ copper transceiver is based on 10GBASE-T, which has the advantage of being an interoperable, standard-based technology that uses the familiar RJ-45 connector and provides backwards compatibility with legacy networks. Supporting top of rack, middle of row or end of row architectures, 10G SFP+ copper transceiver can extend the life of any switch hardware, without having to change the existing infrastructure. The following pictures present the two application cases for 10G SFP+ copper transceiver.
Scenario one: Connecting server and/or storage appliances with 10GBASE-T RJ-45 to a SFP+ network switch
Scenario two: Network upgrade to 10G at edge switches
The new 10GBASE-T SFP+ transceiver module delivers compatibility with Cat 6a UTP structured cabling up to 30m link distance, at a minimum of 0.5W power saving per port embedded over 10GBASE-T RJ45 ports. By using the existing SFP+ port for copper transmission, 10GBASE-T SFP+ copper transceiver offers greater flexibility for low density 10G copper applications than a fixed-port 10G switch. Network Edge equipment, developed with SFP+ ports and designed for the new 10GBASE-T SFP+ transceiver module, can be deployed to precisely match today’s network edge bandwidth demand. It can also be migrated to a pay-as-you-grow model to meet future demand, optimizing initial capital expenditures and ongoing operating costs.