Emulex OM1 Cabling Manual

Cabling Guide for
10GbE Network Adapters
At a Glance
Cables and connectors can cause some
confusion when purchasing new adapters
for servers. There are many options
across many vendors. This technical
brief provides generic information about
cables and connectors for adapters
in a 10Gb Ethernet (10GbE) network
environment. Note that the cable you
select is determined by the switch, not
the adapter, in your environment.
10GbE has been in existence since 2002, yet it seems only recently that serious
interest in 10GbE has taken hold. Due to the history of 10GbE, it has not been
completely backward compatible with previous generations of Ethernet technology,
which has contributed to some confusion about the cables and connectors required
for 10GbE.
10GbE cables
There are two basic cable types available for 10GbE applications: copper and
fiber-optic cables. As interface speeds increase, expect increased usage of fiber
optic cables and connectors for most interfaces. At higher Gigabit speeds (10Gb+),
copper cables and interconnects generally have too much amplitude loss except
for short distances, such as within a rack or to a nearby rack. This amplitude loss is
sometimes called a poor signal-to-noise ratio or simply "too noisy".
Fiber-optic cables
There are two general types of fiber optic cables available: single-mode fiber and
multi-mode fiber.
Single-mode fiber (SMF)—typically with an optical core of approximately 9 µm
n
(microns), has lower modal dispersion than multi-mode fiber and can support
distances of at least 10 Km and as high as 80-100 Km (Kilometers) or more,
depending on transmission speed, transceivers and the buffer credits allocated in
the switches.
Multi-mode fiber (MMF)—with optical core of either 50 µm or 62.5 µm, supports
n
distances up to 600 meters, depending on transmission speeds and transceivers.
Meter-for-meter, single-mode and multi-mode cables are similarly priced. However,
some of the other components used in single-mode links are more expensive than
their multi-mode equivalents.
When planning data center cabling requirements, be sure to consider that a service
life of 15 to 20 years can be expected for fiber optic cabling, so the choices made
today need to support legacy, current and emerging data rates. Also note that
deploying large amounts of new cable in a data center can be labor- intensive,
especially in existing environments.
t e C h n i C a l
B r i e f
C o n n e C t i v i t y