10GbE Standardized to 400 Meters on OM4 Fiber
When the 10 Gigabit Ethernet (10GbE) standard released in 2002, the fiber optic links of 10GBASE-SR were standardized to at least 300 meters over Optical Multimode 3 (OM3) fiber. OM3 is the leading type of multimode fiber being deployed today in the data center, but it isn’t the best fiber any more. Optical Multimode 4 (OM4) fiber was standardized in 2009 by the Telecommunications Industry Association. OM4 is now the latest and greatest multimode fiber and the IEEE is setting the supported distance of 10GbE to at least 400 meters.
When the 40GbE and 100GbE standard was released in 2010, OM4 was designed into the standard and achieved a distance of 150 meters on OM4 fiber while OM3 fiber went 100 meters. The IEEE Maintenance Task Force (http://www.ieee802.org/3/bh/index.html) is currently incorporating several standards (including 802.3ba that defines 40GbE and 100GbE) into the newest revision of the Ethernet standards that should be released this year as 802.3-2012. While incorporating these documents, the task force decided to update 10GbE to support OM4 fiber. See Table 1 for a summary of reaches over different fiber types.
Table 1: Fiber Types and Reach
|
Fiber Type |
Bandwidth*Length Product (MHz*km or GHz*m) |
10GBASE-SR Distance (meters) |
40GBASE-SR4 and 100GBASE-SR10 Distance (meters) |
|
OM1 |
160-200 |
33 |
N/A |
|
OM2 |
400-500 |
82 |
N/A |
|
OM3 |
2000 |
300 |
100 |
|
OM4 |
4700 |
400 |
150 |
The bandwidth of OM4 is especially critical as the IEEE defines the latest version of 100GbE that will consist of 4 lanes of 25Gb/s instead of 10 lanes of 10Gb/s. The IEEE is exploring the latest fiber optic link technologies in the new Next Generation 100Gb/s Optical Ethernet Study Group (http://www.ieee802.org/3/100GNGOPTX/index.html). The group is collecting requirements for links that will run at 4X25Gb/s. The EA would like to hear from end users about what distance you need to support in data centers that are getting larger every year. Please tell us about your link requirements in the comments section of this blog.
You might ask, what’s your point?
My point is that Ethernet is using the latest technology to extend the distance of Ethernet’s fastest speeds. For 10GbE, the IEEE just extended the distance of 10GbE by 100 meters to 400 meters by using OM4 fiber with the same 10GbE modules (transceivers).
Scott Kipp
President of the EA
