Emulex OM1, OM2, OM3, OM4, OS1 Cabling Manual

Cabling Guide for
10GbE Network Adapters

10GbE has been in existence since 2002, yet it seems only recently that serious

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.

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”.

teChniCal

Brief

ConneCtivity

Fiber-optic cables

There are two general types of fiber optic cables available: single-mode fiber and
multi-mode fiber.

n

Single-mode fiber (SMF)—typically with an optical core of approximately 9 µm

(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.

n

Multi-mode fiber (MMF)—with optical core of either 50 µm or 62.5 µm, supports

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.

Cabling Guide for
10GbE Network Adapters

There are different designations for fiber-optic cables depending
on the bandwidth supported.

n

Multi-mode: OM1, OM2, OM3, OM4

n

Single-mode: OS1

10GBASE-SR—Currently, the most common type of fiber-optic
10GbE cable is the 10GBase-SR cable that supports an SFP+
connector with an optical transceiver rated for 10Gb transmission
speed. These are also known as “short reach” fiber-optic cables.

10GBASE-LR—These are the “long reach” fiber optic cables that
support single-mode fiber optic cables and connectors.

OM3 and OM4 are newer multi-mode cables that are “laser
optimized” (LOMMF) and support 10GbE applications. OM3 and
OM4 cables are also the only multi-mode fibers included in the
IEEE 802.3ba 40G/100G Ethernet standard that was ratified in
June 2010. The 40G and 100G speeds are currently achieved by
bundling multiple channels together in parallel with special multi­channel (or multi-lane) connector types. This standard defines
an expected operating range of up to 100m for OM3 and up to
150m for OM4 for 40GbE and 100GbE. These are estimates of
distance only and supported distances may differ when 40GbE
and 100GbE products become available in the coming years. See
the Connector Types section below for additional detail.

Newer multi-mode OM2, OM3 and OM4 (50 µm) and single­mode OS1 (9 µm) fiber-optic cables have been introduced
that can handle tight corners and turns. These are known as
“bend optimized,” “bend insensitive,” or have “enhanced bend
performance.” These fiber-optic cables can have a very small turn
or bend radius with minimal signal loss or “bending loss.” The term
“bend optimized” multi-mode fiber (BOMMF) is sometimes used.

OS1 single-mode fiber optics are used for long distances, up to
10,000m (6.2 miles) with the standard transceivers and have been
known to work at much longer distances with special transceivers
and switching infrastructure.

Each of the multi-mode and single-mode fiber optic cable types
includes two wavelengths. The higher wavelengths are used for
longer-distance connections.

Indoor vs. outdoor cabling

Indoor fiber-optic cables are suitable for indoor building
applications. Outdoor cables, also known as outside plant or OSP,
are suitable for outdoor applications and are water (liquid and
frozen) and ultra-violet resistant. Indoor/outdoor cables provide
the protections of outdoor cables with a fire-retardant jacket that
allows deployment of these cables inside the building entrance
beyond the OSP maximum distance, which can reduce the
number of transition splices and connections needed.

Fiber-optic cable characteristics

Mode Core Diameter Wavelength Modal Bandwidth Cable Jacket Color

OM1

OM2

OM3

OM4

OS1

Fiber-optic cable distance and speed

10 Gbps

The distances shown above are for 850 nm wavelength multi-mode cables. The 1300 nm wavelength cables can support longer
distances.

Multi-mode 62.5 µm 850 nm / 1300 nm 200 MHz Orange

Multi-mode 50 µm 850 nm / 1300 nm 500 MHz Orange

Multi-mode 50 µm 850 nm / 1300 nm 2000 MHz Aqua

Multi-mode 50 µm 850 nm / 1300 nm 4700 MHz Aqua

Single-mode 9 µm 1310 nm / 1550 nm — Yellow

OM1 OM2 OM3 OM4

33m 82m Up to 300m Up to 400m

Cabling Guide for
10GbE Network Adapters

Copper cables

Common forms of 10GbE copper cables are as follows:

10GBASE-CR—Currently, the most common type of copper
10GbE cable is the 10GBase-CR cable that uses an attached
SFP+ connector, also known as a Direct Attach Copper (DAC).
This fits into the same form factor connector and housing as the
fiber-optic cables with SFP+ connectors. Many 10GbE switches
accept cables with SFP+ connectors, which support both copper
and fiber-optic cables. These cables are available in 1m, 3m, 5m,
7m, 8.5m and longer distances. The most commonly deployed
distances are 3m and 5m.

Passive and Active DAC—Passive copper connections are
common with many interfaces. The industry is finding that as
the transfer rates increase, passive copper does not provide the
distance needed and takes up too much physical space. The
industry is moving towards an active copper type of interface for
higher speed connections. Active copper connections include
components that boost the signal, reduce the noise and work with
smaller gauge cables, improving signal distance, cable flexibility
and airflow.

Type Lanes Max. speed

per lane (Gbps)

Copper CX4

Small Form-factor
Pluggable

Small Form-factor
Pluggable enhanced

Quad Small Form­factor Pluggable

Quad Small Form­factor Pluggable
enhanced

CX4 4 5 20 Copper 10GbE, SDR and DDR Infiniband

SFP 1 4 4 Copper,

SFP+ 1 16 16 Copper,

QSFP 4 5 20 Copper,

QSFP+ 4 16 64 Copper,

10 G B A S E-T—These cables and connectors are similar to, but
not the same as the cables used for 1000BASE-T. 10GBASE-T
cables are Cat6a (Category 6 augmented), also known as Class
EA cables. These support the higher frequencies required for
10Gb transmission up to 100 meters (330 feet). Cables must be
certified to at least 500MHz to ensure 10GBASE-T compliance.
Cat7 (Category 7, Class F) cable is also certified for 10GBASE-T
compliance, and is typically deployed in Europe. Cat6 cables may
work in 10GBASE-T deployments up to 55m, but should be tested
first. Some newer 10GbE switches support 10GBASE-T (RJ45)
connectors.

Connectors

Several types of connectors are available for 10GbE cables. Each
of the connector types includes a specific number of lanes, or
channels.

As of early 2011, the fastest generally available connector speeds
supported were 10 Gbps per lane. Significantly higher speeds are
currently achieved by bundling multiple lanes in parallel, such as
4x10 (40Gbps), 10x10 (100Gbps), 12x10 (120Gbps), etc. Most of
the current implementations of 40GbE and 100GbE use multiple
lanes of 10GbE and are considered “channel bonded” solutions.

Max. speed
total (Gbps)

Cable type Usage

1GbE, Fibre Channel: 1, 2, 4Gb

Optical

10GbE, 8Gb & 16Gb Fibre

Optical

Optical

Optical

Channel, 10Gb FCoE

Various

40GbE, DDR, QDR & FDR
Infiniband, 64Gb Fibre Channel

Cabling Guide for
10GbE Network Adapters

Type Diagram

Copper CX4

CX4

Small Form-factor
Pluggable

Quad Small Form-factor
Pluggable

SFP, SFP+

QSFP, QSFP+

When to use different types of 10GbE cables

To summarize, the most common types of 10GbE cables currently use SFP+ connectors.

n

For short distances, such as within a rack or to a nearby rack, use DAC with SFP+ connectors, also known as 10GBASE-CR.

n

For mid-range distances, use laser optimized multi-mode fiber (LOMMF) cables, either OM3 or OM4, with SFP+ connectors.

n

For long-range distances, use single-mode fiber-optic cables (OS1), also known as 10GBASE-LR.

n

If your Ethernet switching infrastructure and network adapters support 10GBASE-T (RJ45) cables and connectors, use Cat6 or Cat6a

cables.

Remember, the cable you select is determined by the switch, not the adapter, in your environment.

Some of these products may not be available in the U.S.
Please contact your supplier for more information.

World Headquarters 3333 Susan Street, Costa Mesa, CA 92626 [phone]
Wokingham, UK [phone] | Munich, Germany [phone]
Paris, France [phone] | Beijing, China [phone]
Tokyo, Japan [phone] | Bangalore, India [phone]

Emulex Connects™ Servers, Storage and People

twitter.com/emulex bit.ly/emulexlinks bit.ly/emulexfbfriendfeed.com/emulex

www.emulex.com

©2012 Emulex, Inc. All rights reserved. This document refers to various companies and products by their trade names. In most,
if not all cases, their respective companies claim these designations as trademarks or registered trademarks. This information
is provided for reference only. Although this information is believed to be accurate and reliable at the time of publication, Emulex
assumes no responsibility for errors or omissions. Emulex reserves the right to make changes or corrections without notice.
This report is the property of Emulex and may not be duplicated without permission from the Company.

13-1085 · 3/13