Tag Archives: 10 Gigabit Ethernet

Unique Advantages of 10GBASE-T in Migrating Data Center to 10GbE

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Over the last decade, large enterprises have been migrating data center infrastructures from 100MB Ethernet to 1/10 Gigabit Ethernet (GbE) to support high-bandwidth, mission critical applications. However, many mid-market companies found themselves restricted from this migration to 10GbE technology due to cost, low port density and high power consumption. For many of these companies, the explosive growth of technologies, data and applications is severely taxing existing 1GbE infrastructures and affecting performance. So it’s high time for them to upgrade the data center to 10GbE. With many 10GbE interfaces options such as CX4, SFP+ Fiber, SFP+ Direct Attach Copper (DAC), and 10GBASE-T offered, which one is the best? In fact, the answer is 10GBASE-T.

Shortcomings of SFP+ in 10GbE Data Center Cabling
SFP+ has been adopted on Ethernet adapters and switches and supports both copper and fiber optic cables makes it a better solution than CX4, which is the mainstream 10GbE adoption today. However, SFP+ is not backward-compatible with the twisted-pair 1GbE broadly deployed throughout the data center. SFP+ connectors and their cabling were not compatible with the RJ-45 connectors used on 1GbE networks. Enterprise customers cannot just start adding SFP+ 10GbE to an existing RJ-45 1GbE infrastructure. New switches and new cables are required, which is a big chunk of change.

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Advantages of 10GBASE-T in 10GbE Data Center Cabling
10GBASE-T is backward-compatible with 1000BASE-T, it can be deployed in existing 1GbE switch infrastructures in the data centers that are cabled with CAT6, CAT6A or above cabling. As we know, 1GbE is still widely used in data center. 10GBASE-T is backwards compatible with 1GbE and thus will become the perfect choice for gradual transitioning from 1GbE deployment to 10GbE. Additional advantages include:

  • Reach
    Like all BASE-T implementations, 10GBASE-T works for lengths up to 100 meters giving IT managers a far-greater level of flexibility in connecting devices in the data center. With flexibility in reach, 10GBASE-T can accommodate either top of the rack, middle of row, or end of the row network topologies. This gives IT managers the most flexibility in server placement since it will work with existing structured cabling systems.
  • Power
    The challenge with 10GBASE-T is that even single-chip 10GBASE-T adapters consume a watt or two more than the SFP+ alternatives. More power consumption is not a good thing in the data center. However, the expected incremental costs in power over the life of a typical data center are far less than the amount of money saved from reduced cabling costs. Besides, with process improvements, chips improved from one generation to the next. The power and cost of the latest 10GBASE-T PHYs will be reduced greatly than before.
  • Reliability
    Another challenge with 10GBASE-T is whether it could deliver the reliability and low bit-error rate of SFP+. This skepticism can also be expressed as whether the high demands of FCoE could be met with 10GBASE-T. In fact, Cisco has announced that it had successfully qualified FCoE over 10GBASE-T and is supporting it on its newer switches that support 10GBASE-T in 2013.
  • Latency
    Depending on packet size, latency for 1000BASE-T ranges from sub-microsecond to over 12 microseconds. 10GBASE-T ranges from just over 2 microseconds to less than 4 microseconds, a much narrower latency range. For Ethernet packet sizes of 512B or larger, 10GBASE-T’s overall throughout offers an advantage over 1000BASE-T. Latency for 10GBASE-T is more than 3 times lower than 1000BASE-T at larger packet sizes. Only the most latent sensitive applications such as HPC or high frequency trading systems would notice any latency.
  • Cost
    When it comes to capital costs, copper cables offer great savings. Typically, passive copper cables are two to five times less expensive for comparable lengths of fiber. In a 1,000-node cluster, with hundreds of required cables, that can translate into the hundreds of thousands of dollars. Extending that into even larger data centers, the savings can reach into the millions. Besides, copper cables do not consume power and because their thermal design requires less cooling, there are extensive savings on operating expenditures within the data center. Hundreds of kilowatts can be saved by using copper cables versus fiber.

Conclusion
The 10GbE standards are mature, reliable and well understood. 10GBASE-T breaks through important cost and cable installation barriers in 10GbE deployment as well as offering investment protection via backwards compatibility with 1GbE networks. Deployment of 10GBASE-T will simplify the networking transition by providing an easier path to migrate to 10GbE infrastructure in support of higher bandwidth needed for virtualized servers. In the future, 10GBASE-T will be the best option for 10GbE data center cabling!

Three Types Physical Media Systems For 10 Gigabit Ethernet

Overview

Dramatic growth in data center throughput has led to the increasing usage and demand for higher-performance servers, storage and interconnects. As a result, we are seeing the expansion of higher speed Ethernet solutions, specifically 10 and 40 gigabit Ethernet. This text will take an overview of 10 gigabit ethernet as well as introducing some common 10-gigabit physical media systems: fiber optic media systems, DAC cable media systems and twisted-pair media systems.

Introduction of 10 Gigabit Ethernet

10 Gigabit Ethernet is a group of computer networking technologies for transmitting Ethernet frames at a rate of 10 gigabits per second. It was first defined by the IEEE 802.3ae-2002 standard. Unlike previous Ethernet standards, 10 Gigabit Ethernet defines only full duplex point-to-point links which are generally connected by network switches. Like previous versions of Ethernet, 10GbE can use either copper or fiber cabling. However, the 10 Gigabit Ethernet standard encompasses a number of different physical layer (PHY) standards. A networking device may have different PHY types through pluggable PHY modules, such as those based on XENPAK, XFP and SFP+.

Classification of 10 Gigabit Ethernet

When comes to 10 gigabit Ethernet (10GbE), IT managers are now faced with the challenge of selecting the appropriate 10-gigabit physical media. Broadly, this media is usually offered in the following three categories:

10 Gigabit Ethernet Fiber Optic Media Systems Solution

There are two classifications for optical fiber: single-mode (SMF) and multimode (MMF). SMF is used for long distance communication and MMF is used for distances of less than 300 m. There are also active optical cables (AOC). These have the optical electronics already connected eliminating the connectors between the cable and the optical module. They plug into standard optical module sockets. They are lower cost than other optical solutions because the manufacturer can match the electronics to the required length and type of cable. AOC Cable provides very short distance (same shelf) inexpensive connectivity at 10G rates between two 10G data ports. The following picture shows the SFP+ active optical cables (AOC):

SFP-10G-AOC3M

NOTE: Dramatically reducing 10G interconnectivity costs, the 10G cables can provide inexpensive and reliable 10G speed connections using either copper cables with distances reaching up to 15 meters or active optical cables reaching even 100 meters.

10 Gigabit Ethernet Copper Direct Attach Cable Media Systems (10GSFP+Cu) Solution

SFP+ direct attach cable (DAC), also known as 10GSFP+Cu, is a copper 10GBASE Twinax Cable which comes in either an active or passive twinax cable assembly and connects directly into an SFP+ housing. SFP+ direct attach cable has a fixed-length cable, typically 1 to 7 m (passive cables) or up to 15 m (active cables) in length. And like 10GBASE-CX4, is low-power, low-cost and low-latency with the added advantages of using less bulky cables and of having the small form factor of SFP+. Besides, SFP+ direct attached Twinax copper today is tremendously popular, with more ports installed than 10GBASE-SR. The following picture shows the SFP+ passive direct attach cable(DAC):

passive SFP+ cable

10 Gigabit Ethernet Twisted-Pair Media Systems (10GBASE-T) Solution

10GBASE-T is a standard released in 2006 to provide 10 Gbit/s connections over unshielded or shielded twisted pair cables, over distances up to 100 metres. 10GBASE-T cable solution can also be used for 1000BASE-T allowing a gradual upgrade from 1000BASE-T using auto negotiation to select which speed to use. 10GBASE-T uses the IEC 60603-7 8P8C (commonly known as RJ45) connectors already widely used with Ethernet. Transmission characteristics are now specified to 500 MHz. To reach this frequency Category 6A or better balanced twisted pair cables are needed to carry 10GBASE-T up to distances of 100m. The following picture shows the Category 6A cable:

Cat 6a cable for 10 gigabit ethernet