Posted by: Paul Kish on May 07, 2015
Ethernet has taken the world by storm, from the early days of computers connected on shared networks operating at 10 Mb/s to dedicated high speed networks today operating at 10 Gb/s over copper and 100 Gb/s over optical fiber. Today these connections are not just between computers but all kinds of fixed and mobile devices sending and receiving all kinds of information, including high definition pictures and videos, large data transfers, tracking and positioning systems, 3D rendering, etc.
Ever-increasing bandwidth consumption and connectivity requirements mean that more businesses rely on Ethernet for improved speeds, availability and reliability. As Ethernet grows in breadth and complexity, the copper and fiber optic cabling systems required to support these networks are advancing as well.
Let’s walk through a brief history of recent Ethernet standards – and the cabling that supports it – to see just how far we’ve come.
The 1000BASE-T Ethernet standard was published in the late 1990s; 1000BASE-T is widely used in data centers for switch-to-server connections and on the edge for desktop computer connections.
As a minimum, 1000BASE-T installations require Category 5e cabling to support the gigabit data rate. For new installations Category 6 cabling is recommended because of the lower signal loss and the improved performance in a noisy environment. Also, for Power over Ethernet (PoE) applications, Category 6 cabling, with larger 23 AWG conductors, generates less heat within the cable delivering higher power levels more efficiently. Category 6 cabling is now being installed in most buildings to support devices like IP cameras, VoIP phones, routers, lighting controls, and other low-voltage systems. (Determining the amount of power that can be delivered to a device through cabling isn’t always black and white, however; cable type and configuration often determine what will work best.)
Not only does Category 6 cable allow more efficient power delivery and data to be provided on Ethernet cabling, but it also has lower loss as well, so it can be used for longer reach or higher temperatures without length de-rating.
The IEEE 802.3 10GBASE-T standard was published in 2006. Category 6 cable is not specifically designed to support 10GBASE-T Ethernet. Installed base Category 6 cabling may be used for 10GBASE-T after validation testing with significant limitations on cable bundling and reach, see TIA-TSB-155-A. Category 6A cabling is recommended to support 10 Gb/s connections across distances of up to 100 meters (330 feet).
Category 6A cabling performance is specified at frequencies of up to 500 MHz (twice that of Category 6 cable)). It also has additional specifications for alien crosstalk between cables and connectors. Alien crosstalk is the dominant interference source for 10GBASE-T operation. The alien crosstalk of Category 6A cabling is about 30 times less than Category 6 cabling.
Although Category 6A cabling has been around for some time, it has not been widely adopted in the enterprise. One of the reasons is that the cable diameter is significantly larger than Category 6 cables. This is about to change. Belden’s latest 3rd generation 10GXS Category 6A cable is comparable in size to high end Category 6 cables, occupying 25% less space in cable pathways. It can also deliver up to 100 Watts of power within the maximum constraints of 10 °C temperature rise specified in IEEE 802.3at and IEEE 802.3bt (draft) standards.
Two new Ethernet standards loom on the horizon: 2.5GBASE-T and 5.0GBASE-T. These new standards have been proposed by IEEE 802.3, and are derivatives of 10GBASE-T. Although the two standards have not yet been defined, installed Category 6 cabling may be able to support these data rates if it passes required performance tests. (It may also be possible to use installed Category 5e cabling to support 2.5GBASE-T.)
The 40G and 100G Ethernet standards, both developed in 2010, support the growth of bandwidth-intensive applications and need for speed (virtualization, high-performance computing, VoIP, etc.). Only OM3 and OM4 multimode fiber is capable of supporting the bandwidth increases brought forth by 40G and 100G Ethernet standards. These standards use a parallel optics implementation based on 10G Ethernet: 40G Ethernet requires eight-fiber cable (most likely a 12-fiber cable with four fiber strands not being used) while 100G Ethernet requires 20 fiber strands (most likely two 12-fiber cables).
Ensuring the appropriate grade and length of fiber is essential to smooth, seamless operation in these applications.
Belden has experts available to discuss options and answer questions regarding the cabling type that will best support your environment. Schedule a call with us to learn more!