10 Gigabit Ethernet
Encyclopedia
The 10 gigabit Ethernet (10GE or 10GbE or 10 GigE) computer network
ing standard was first published in 2002. It defines a version of Ethernet
with a nominal data rate of 10 Gbit/s (billion bits per second), ten times faster than gigabit Ethernet
.
10 gigabit Ethernet defines only full duplex
point to point links which are generally connected by network switch
es. Half duplex
operation, hubs and CSMA/CD (carrier sense multiple access with collision detection) do not exist in 10GbE.
The 10 gigabit Ethernet standard encompasses a number of different physical layer
(PHY) standards. A networking device may support different PHY types through pluggable PHY modules, such as those based on SFP+. Over time market forces will determine the most popular 10GE PHY types.
At the time that the 10 gigabit Ethernet standard was developed, interest in 10GbE as a wide area network
(WAN) transport led to the introduction of a WAN PHY for 10GbE. This operates at a slightly slower data-rate than the local area network
(LAN) PHY and adds some extra encapsulation. Both share the same Physical Medium Dependent sublayers so can use the same optics.
In 2007 one million 10GbE ports were shipped, in 2009 two million ports were shipped and in 2010 over three million ports were shipped.
(IEEE) 802.3 working group
has published several standards relating to 10GbE. These included: 802.3ae-2002 (fiber -SR, -LR, -ER and -LX4 PMDs), 802.3ak-2004 (-CX4 copper twin-ax InfiniBand
type cable), 802.3an-2006 (10GBASE-T copper twisted pair
), 802.3ap-2007 (copper backplane -KR and -KX4 PMDs) and 802.3aq-2006 (fiber -LRM PMD with enhanced equalization).
The 802.3ae-2002 and 802.3ak-2004 amendments were consolidated into the IEEE 802.3-2005 standard. IEEE 802.3-2005 and the other amendments were consolidated into IEEE Std 802.3-2008.
(and related X2 and XPAK), XFP and SFP+. When choosing a PHY module, a designer considers cost, reach, media type, power consumption, and size (form factor).
XENPAK was the first MSA for 10GE and had the largest form factor. X2 and XPAK were later competing standards with smaller form factors. X2 and XPAK have not been as successful in the market as XENPAK. XFP came after X2 and XPAK and it is also smaller.
The newest module standard is the enhanced small form-factor pluggable transceiver, generally called SFP+. Based on the small form-factor pluggable transceiver (SFP) and developed by the ANSI T11 fibre channel
group, it is smaller still and lower power than XFP. SFP+ has become the most popular socket on 10GE systems. SFP+ modules do only optical to electrical conversion, no clock and data recovery, putting a higher burden on the host's channel equalization. SFP+ modules share a common physical form factor with legacy SFP modules, allowing higher port density than XFP and the re-use of existing designs for 24 or 48 ports in a 19" rack width blade.
Optical modules are connected to a host by either a XAUI
, XFI or SFI interface. XENPAK, X2, and XPAK modules use XAUI to connect to their hosts. XAUI (XGXS) uses a four-lane data channel and is specified in IEEE 802.3 Clause 48. XFP modules use a XFI interface and SFP+ modules use an SFI interface. XFI and SFI use a single lane data channel and the encoding specified in IEEE 802.3 Clause 49.
SFP+ modules can further be grouped into two types of host interfaces: linear or limiting. Limiting modules are preferred except when using old fiber infrastructure which requires the use of the linear interface provided by 10GBASE-LRM modules.
There are two classifications for optical fiber
: single-mode (SMF
) and multi-mode (MMF
). In SMF light follows a single path through the fiber while in MMF it takes multiple paths resulting in differential mode delay (DMD). SMF is used for long distance communication and MMF is used for distances of less than 300 m. SMF has a narrower core (8.3 µm) which requires a more precise termination and connection method. MMF has a wider core (50 or 62.5 µm). The advantage of MMF is that it can be driven by low cost VCSEL lasers for short distances, and multimode connectors are cheaper and easier to terminate reliably in the field. The advantage of SMF is that it can work over longer distances.
In the 802.3 standard reference is made to FDDI-grade MMF fiber. This has a 62.5 µm core and a minimum modal bandwidth of 160 MHz*km at 850 nm. It was originally installed in the early 1990s for FDDI and 100BaseFX networks. The 802.3 standard also references ISO/IEC 11801
which specifies OM1, OM2, OM3 and OM4 MMF fiber types. OM1 has a 62.5 µm core while the others have a 50 µm core. At 850 nm the minimum modal bandwidth of OM1 is 200 MHz*km, of OM2 500 MHz*km, of OM3 2000 MHz*km and of OM4 4700 MHz*km. FDDI-grade cable is now obsolete and new structured cabling
installations use either OM3 or OM4 cabling. OM3 cable can carry 10GbE 300 metres using low cost 10GBASE-SR optics (OM4 can manage 400 metres) .
To distinguish SMF from MMF cables, SMF cables are usually yellow, while MMF cables are orange (OM1 & OM2) or aqua (OM3 & OM4) however it must be noted that in fibre optics there is no agreed colour for any specific optical speed or technology with the exception being angular physical connector (APC), it being an agreed colour of green.
There are also active optical cables. 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.
64B/66B PCS is defined in IEEE 802.3 Clause 49 and its Physical Medium Dependent PMD in Clause 52. It delivers serialized data at a line rate of 10.3125 Gbit/s.
Over obsolete FDDI-grade 62.5 micron multi-mode fiber cabling it has a maximum range of 26 metres, over 62.5 micron OM1 it has a range of 33 metres, over 50 micron OM2 a range of 82 metres, over OM3 300 metres and over OM4 400 metres.
OM3 and OM4 are the preferred choices for structured optical cabling within buildings. MMF has the advantage over SMF of having lower cost connectors because of its wider core.
The 10GBASE-SR transmitter is implemented with a vertical-cavity surface-emitting laser (VCSEL) which is low cost and low power. OM3 and OM4 optical cabling is sometimes described as laser optimized because they have been designed to work with VCSELs. 10GBASE-SR delivers the lowest cost, lowest power and smallest form factor optical modules.
For 2011, 10GBASE-SR is projected to make up a quarter of the total 10GbE adapter ports shipped.
There is a non-standard lower cost, lower power variant sometimes referred to as 10GBASE-SRL (10GBASE-SR lite). This is inter-operable with 10GBASE-SR but only has a reach of 100 metres.
64B/66B PCS is defined in IEEE 802.3 Clause 49 and its Physical Medium Dependent PMD in Clause 52. It delivers serialized data at a line rate of 10.3125 Gbit/s.
10GBASE-LR has a specified reach of 10 kilometres (6.2 mi), but 10GBASE-LR optical modules can often manage distances of up to 25 kilometres (15.5 mi) with no data loss.
Fabry–Pérot lasers are commonly used in 10GBASE-LR optical modules. Fabry–Pérot lasers are more expensive than VCSELs but their high power and longer wavelength allow efficient coupling into the small core of single mode fiber over greater distances.
64B/66B PCS is defined in IEEE 802.3 Clause 49 and its Physical Medium Dependent PMD in Clause 68. It delivers serialized data at a line rate of 10.3125 Gbit/s.
10GBASE-LRM supports distances up to 220 metres (721.8 ft) on FDDI-grade multi-mode fiber and the same 220m maximum reach on OM1, OM2 and OM3 fiber types. 10GBASE-LRM reach is not quite as far as the older 10GBASE-LX4 standard.
Some 10GBASE-LRM transceivers also support distances up to 300 metres (984.3 ft) on standard single-mode fiber (SMF, G.652), however this is not part of the IEEE or MSA specification.
10GBASE-LRM uses electronic dispersion control (EDC) for receive equalization.
10GBASE-LRM has been a failure in the market.
64B/66B PCS is defined in IEEE 802.3 Clause 49 and its Physical Medium Dependent PMD in Clause 52. It delivers serialized data at a line rate of 10.3125 Gbit/s.
10GBASE-ER has a reach of 40 kilometres (24.9 mi) over engineered links and 30 km over standard links.
specifications.
The 802.3 standard will not be amended to cover the ZR PHY.
8B10B PCS is defined in IEEE 802.3 Clause 48 and its Physical Medium Dependent PMD in Clause 53.
It supports a range of 300 metres (984.3 ft) over FDDI-grade, OM1, OM2 and OM3 multi-mode cabling (all these fiber types are specified to have a minimum modal bandwidth of 500 MHz*km at 1300 nm).
10GBASE-LX4 also supports a range of 10 kilometres (6.2 mi) over SMF.
For MMF links the WDM output needs to be be coupled through a SMF offset-launch mode-conditioning patch cord. This is explained in subclauses 53.6 and 38.11.4 of the IEEE 802.3 spec.
Until 2005 10GBASE-LX4 optical modules were cheaper than 10GBASE-LR optical modules.
10GBASE-LX4 was used by people who wanted to support both MMF and SMF with a single optical module.
10GBASE-LX4 is now an obsolete technology and has no significant market presence.
cabling, twisted pair
cabling, and backplane
s.
technology. It is specified to work up to a distance of 15 m (49.2 ft). Each lane carries 3.125 G baud of signaling bandwidth.
10GBASE-CX4 offers the advantages of low power, low cost and low latency, but has a bigger form factor and more bulky cables than the newer single lane SFP+ standard and a much shorter reach than fibre or 10GBASE-T.
Shipments of 10GBASE-CX4 today are very low.
applications such as blade servers and routers/switches with upgradable line card
s. 802.3ap implementations are required to operate in an environment comprising up to 1 metres (39.4 in) of copper printed circuit board with two connectors. The standard defines two port types for 10 Gbit/s (10GBASE-KX4 and 10GBASE-KR) and a 1 Gbit/s port type (1000BASE-KX). It also defines an optional layer for FEC
, a backplane autonegotiation protocol and link training for 10GBASE-KR where the receiver can set a three tap transmit equalizer. The autonegotiation protocol selects between 1000BASE-KX, 10GBASE-KX4, 10GBASE-KR or 40GBASE-KR4 operation. 40GBASE-KR4 is defined in 802.3ba.
New backplane designs use 10GBASE-KR rather than 10GBASE-KX4.
cables, over distances up to 100 metres (328.1 ft). 10GBASE-T cable infrastructure can also be used for 1000BASE-T allowing a gradual upgrade from 1000BASE-T using autonegotiation to select which speed to use. 10GBASE-T has higher latency (1 microsecond) and consumes more power than other 10 gigabit Ethernet physical layers. As of 2010 10GBASE-T silicon is available from several manufacturers with claimed power dissipation of 3-4 W at structure widths of 40 nm. and with 28 nm in development, power will continue to decline.
s can carry 10GBASE-T for shorter distances when qualified according to the guidelines in ISO TR 24750 or TIA-155-A.
(THP) version of pulse-amplitude modulation
with 16 discrete levels (PAM-16), encoded in a two-dimensional checkerboard pattern known as DSQ128. Several proposals were considered for wire-level modulation, including PAM with 12 discrete levels (PAM-12), 10 levels (PAM-10), or 8 levels (PAM-8), both with and without Tomlinson-Harashima Precoding (THP). PAM-5 is what is used in the older 1000BASE-T gigabit Ethernet
standard.
64B/66B PCS is defined in IEEE 802.3 Clause 49 and its Physical Medium Dependent PMDs in Clauses 52. It also uses a WAN Interface Sublayer (WIS) defined in Clause 50 which adds extra encapsulation to format the frame data to be compatible with SONET STS-192c.
The WAN PHY was designed to interoperate with OC-192/STM-64 SDH/SONET
equipment using a light-weight SDH/SONET frame running at 9.953 Gbit/s.
The WAN PHY is a niche product and rarely used.
and connect to the LAN with a choice of PHY modules.
Computer network
A computer network, often simply referred to as a network, is a collection of hardware components and computers interconnected by communication channels that allow sharing of resources and information....
ing standard was first published in 2002. It defines a version of Ethernet
Ethernet
Ethernet is a family of computer networking technologies for local area networks commercially introduced in 1980. Standardized in IEEE 802.3, Ethernet has largely replaced competing wired LAN technologies....
with a nominal data rate of 10 Gbit/s (billion bits per second), ten times faster than gigabit Ethernet
Gigabit Ethernet
Gigabit Ethernet is a term describing various technologies for transmitting Ethernet frames at a rate of a gigabit per second , as defined by the IEEE 802.3-2008 standard. It came into use beginning in 1999, gradually supplanting Fast Ethernet in wired local networks where it performed...
.
10 gigabit Ethernet defines only full duplex
Duplex (telecommunications)
A duplex communication system is a system composed of two connected parties or devices that can communicate with one another in both directions. The term multiplexing is used when describing communication between more than two parties or devices....
point to point links which are generally connected by network switch
Network switch
A network switch or switching hub is a computer networking device that connects network segments.The term commonly refers to a multi-port network bridge that processes and routes data at the data link layer of the OSI model...
es. Half duplex
Duplex (telecommunications)
A duplex communication system is a system composed of two connected parties or devices that can communicate with one another in both directions. The term multiplexing is used when describing communication between more than two parties or devices....
operation, hubs and CSMA/CD (carrier sense multiple access with collision detection) do not exist in 10GbE.
The 10 gigabit Ethernet standard encompasses a number of different physical layer
Physical layer
The physical layer or layer 1 is the first and lowest layer in the seven-layer OSI model of computer networking. The implementation of this layer is often termed PHY....
(PHY) standards. A networking device may support different PHY types through pluggable PHY modules, such as those based on SFP+. Over time market forces will determine the most popular 10GE PHY types.
At the time that the 10 gigabit Ethernet standard was developed, interest in 10GbE as a wide area network
Wide area network
A wide area network is a telecommunication network that covers a broad area . Business and government entities utilize WANs to relay data among employees, clients, buyers, and suppliers from various geographical locations...
(WAN) transport led to the introduction of a WAN PHY for 10GbE. This operates at a slightly slower data-rate than the local area network
Local area network
A local area network is a computer network that interconnects computers in a limited area such as a home, school, computer laboratory, or office building...
(LAN) PHY and adds some extra encapsulation. Both share the same Physical Medium Dependent sublayers so can use the same optics.
In 2007 one million 10GbE ports were shipped, in 2009 two million ports were shipped and in 2010 over three million ports were shipped.
Standards
Over the years the Institute of Electrical and Electronics EngineersInstitute of Electrical and Electronics Engineers
The Institute of Electrical and Electronics Engineers is a non-profit professional association headquartered in New York City that is dedicated to advancing technological innovation and excellence...
(IEEE) 802.3 working group
IEEE 802.3
IEEE 802.3 is a working group and a collection of IEEE standards produced by the working group defining the physical layer and data link layer's media access control of wired Ethernet. This is generally a local area network technology with some wide area network applications...
has published several standards relating to 10GbE. These included: 802.3ae-2002 (fiber -SR, -LR, -ER and -LX4 PMDs), 802.3ak-2004 (-CX4 copper twin-ax InfiniBand
InfiniBand
InfiniBand is a switched fabric communications link used in high-performance computing and enterprise data centers. Its features include high throughput, low latency, quality of service and failover, and it is designed to be scalable...
type cable), 802.3an-2006 (10GBASE-T copper twisted pair
Twisted pair
Twisted pair cabling is a type of wiring in which two conductors are twisted together for the purposes of canceling out electromagnetic interference from external sources; for instance, electromagnetic radiation from unshielded twisted pair cables, and crosstalk between neighboring pairs...
), 802.3ap-2007 (copper backplane -KR and -KX4 PMDs) and 802.3aq-2006 (fiber -LRM PMD with enhanced equalization).
The 802.3ae-2002 and 802.3ak-2004 amendments were consolidated into the IEEE 802.3-2005 standard. IEEE 802.3-2005 and the other amendments were consolidated into IEEE Std 802.3-2008.
Physical layer modules
To support different 10GbE physical layer standards, many interfaces consist of a standard socket into which different PHY modules may be plugged. Physical layer modules are not specified in an official standards body but by multi-source agreements (MSAs) that can be negotiated more quickly. Relevant MSAs for 10GbE include XENPAKXENPAK
XENPAK is a Multisource Agreement , instigated by Agilent Technologies and Agere Systems, that defines a fiber-optic or wired transceiver module which conforms to the 10 Gigabit Ethernet standard of the Institute of Electrical and Electronics Engineers 802.3 working group...
(and related X2 and XPAK), XFP and SFP+. When choosing a PHY module, a designer considers cost, reach, media type, power consumption, and size (form factor).
XENPAK was the first MSA for 10GE and had the largest form factor. X2 and XPAK were later competing standards with smaller form factors. X2 and XPAK have not been as successful in the market as XENPAK. XFP came after X2 and XPAK and it is also smaller.
The newest module standard is the enhanced small form-factor pluggable transceiver, generally called SFP+. Based on the small form-factor pluggable transceiver (SFP) and developed by the ANSI T11 fibre channel
Fibre Channel
Fibre Channel, or FC, is a gigabit-speed network technology primarily used for storage networking. Fibre Channel is standardized in the T11 Technical Committee of the InterNational Committee for Information Technology Standards , an American National Standards Institute –accredited standards...
group, it is smaller still and lower power than XFP. SFP+ has become the most popular socket on 10GE systems. SFP+ modules do only optical to electrical conversion, no clock and data recovery, putting a higher burden on the host's channel equalization. SFP+ modules share a common physical form factor with legacy SFP modules, allowing higher port density than XFP and the re-use of existing designs for 24 or 48 ports in a 19" rack width blade.
Optical modules are connected to a host by either a XAUI
XAUI
XAUI is a standard for extending the XGMII between the MAC and PHY layer of 10 Gigabit Ethernet . XAUI is pronounced "zowie", a concatenation of the Roman numeral X, meaning ten, and the initials of "Attachment Unit Interface"...
, XFI or SFI interface. XENPAK, X2, and XPAK modules use XAUI to connect to their hosts. XAUI (XGXS) uses a four-lane data channel and is specified in IEEE 802.3 Clause 48. XFP modules use a XFI interface and SFP+ modules use an SFI interface. XFI and SFI use a single lane data channel and the encoding specified in IEEE 802.3 Clause 49.
SFP+ modules can further be grouped into two types of host interfaces: linear or limiting. Limiting modules are preferred except when using old fiber infrastructure which requires the use of the linear interface provided by 10GBASE-LRM modules.
Optical fiber
Optical fiber
An optical fiber is a flexible, transparent fiber made of a pure glass not much wider than a human hair. It functions as a waveguide, or "light pipe", to transmit light between the two ends of the fiber. The field of applied science and engineering concerned with the design and application of...
: single-mode (SMF
Single-mode optical fiber
In fiber-optic communication, a single-mode optical fiber is an optical fiber designed to carry only a single ray of light . Modes are the possible solutions of the Helmholtz equation for waves, which is obtained by combining Maxwell's equations and the boundary conditions...
) and multi-mode (MMF
Multi-mode optical fiber
Multi-mode optical fiber is a type of optical fiber mostly used for communication over short distances, such as within a building or on a campus...
). In SMF light follows a single path through the fiber while in MMF it takes multiple paths resulting in differential mode delay (DMD). SMF is used for long distance communication and MMF is used for distances of less than 300 m. SMF has a narrower core (8.3 µm) which requires a more precise termination and connection method. MMF has a wider core (50 or 62.5 µm). The advantage of MMF is that it can be driven by low cost VCSEL lasers for short distances, and multimode connectors are cheaper and easier to terminate reliably in the field. The advantage of SMF is that it can work over longer distances.
In the 802.3 standard reference is made to FDDI-grade MMF fiber. This has a 62.5 µm core and a minimum modal bandwidth of 160 MHz*km at 850 nm. It was originally installed in the early 1990s for FDDI and 100BaseFX networks. The 802.3 standard also references ISO/IEC 11801
ISO/IEC 11801
International standard ISO/IEC 11801 specifies general-purpose telecommunication cabling systems that are suitable for a wide range of applications . It covers both balanced copper cabling and optical fibre cabling...
which specifies OM1, OM2, OM3 and OM4 MMF fiber types. OM1 has a 62.5 µm core while the others have a 50 µm core. At 850 nm the minimum modal bandwidth of OM1 is 200 MHz*km, of OM2 500 MHz*km, of OM3 2000 MHz*km and of OM4 4700 MHz*km. FDDI-grade cable is now obsolete and new structured cabling
Structured cabling
Structured cabling is building or campus telecommunications cabling infrastructure that consists of a number of standardized smaller elements called subsystems.Structured cabling falls into six subsystems:...
installations use either OM3 or OM4 cabling. OM3 cable can carry 10GbE 300 metres using low cost 10GBASE-SR optics (OM4 can manage 400 metres) .
To distinguish SMF from MMF cables, SMF cables are usually yellow, while MMF cables are orange (OM1 & OM2) or aqua (OM3 & OM4) however it must be noted that in fibre optics there is no agreed colour for any specific optical speed or technology with the exception being angular physical connector (APC), it being an agreed colour of green.
There are also active optical cables. 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.
10GBASE-SR
10GBASE-SR ("short range") is a port type for multi-mode fiber and uses 850 nm lasers. Its Physical Coding SublayerPhysical Coding Sublayer
- Description :The Physical Coding Sublayer further helps to define physical layer specifications for networking protocols like Fast Ethernet, Gigabit Ethernet and 10 Gigabit Ethernet....
64B/66B PCS is defined in IEEE 802.3 Clause 49 and its Physical Medium Dependent PMD in Clause 52. It delivers serialized data at a line rate of 10.3125 Gbit/s.
Over obsolete FDDI-grade 62.5 micron multi-mode fiber cabling it has a maximum range of 26 metres, over 62.5 micron OM1 it has a range of 33 metres, over 50 micron OM2 a range of 82 metres, over OM3 300 metres and over OM4 400 metres.
OM3 and OM4 are the preferred choices for structured optical cabling within buildings. MMF has the advantage over SMF of having lower cost connectors because of its wider core.
The 10GBASE-SR transmitter is implemented with a vertical-cavity surface-emitting laser (VCSEL) which is low cost and low power. OM3 and OM4 optical cabling is sometimes described as laser optimized because they have been designed to work with VCSELs. 10GBASE-SR delivers the lowest cost, lowest power and smallest form factor optical modules.
For 2011, 10GBASE-SR is projected to make up a quarter of the total 10GbE adapter ports shipped.
There is a non-standard lower cost, lower power variant sometimes referred to as 10GBASE-SRL (10GBASE-SR lite). This is inter-operable with 10GBASE-SR but only has a reach of 100 metres.
10GBASE-LR
10GBASE-LR ("long reach") is a port type for single-mode fiber and uses 1310 nm lasers. Its Physical Coding SublayerPhysical Coding Sublayer
- Description :The Physical Coding Sublayer further helps to define physical layer specifications for networking protocols like Fast Ethernet, Gigabit Ethernet and 10 Gigabit Ethernet....
64B/66B PCS is defined in IEEE 802.3 Clause 49 and its Physical Medium Dependent PMD in Clause 52. It delivers serialized data at a line rate of 10.3125 Gbit/s.
10GBASE-LR has a specified reach of 10 kilometres (6.2 mi), but 10GBASE-LR optical modules can often manage distances of up to 25 kilometres (15.5 mi) with no data loss.
Fabry–Pérot lasers are commonly used in 10GBASE-LR optical modules. Fabry–Pérot lasers are more expensive than VCSELs but their high power and longer wavelength allow efficient coupling into the small core of single mode fiber over greater distances.
10GBASE-LRM
10GBASE-LRM, (Long Reach Multimode) originally specified in IEEE 802.3aq is a port type for multi-mode fiber and uses 1310 nm lasers. Its Physical Coding SublayerPhysical Coding Sublayer
- Description :The Physical Coding Sublayer further helps to define physical layer specifications for networking protocols like Fast Ethernet, Gigabit Ethernet and 10 Gigabit Ethernet....
64B/66B PCS is defined in IEEE 802.3 Clause 49 and its Physical Medium Dependent PMD in Clause 68. It delivers serialized data at a line rate of 10.3125 Gbit/s.
10GBASE-LRM supports distances up to 220 metres (721.8 ft) on FDDI-grade multi-mode fiber and the same 220m maximum reach on OM1, OM2 and OM3 fiber types. 10GBASE-LRM reach is not quite as far as the older 10GBASE-LX4 standard.
Some 10GBASE-LRM transceivers also support distances up to 300 metres (984.3 ft) on standard single-mode fiber (SMF, G.652), however this is not part of the IEEE or MSA specification.
10GBASE-LRM uses electronic dispersion control (EDC) for receive equalization.
10GBASE-LRM has been a failure in the market.
10GBASE-ER
10GBASE-ER ("extended reach") is a port type for single-mode fiber and uses 1550 nm lasers. Its Physical Coding SublayerPhysical Coding Sublayer
- Description :The Physical Coding Sublayer further helps to define physical layer specifications for networking protocols like Fast Ethernet, Gigabit Ethernet and 10 Gigabit Ethernet....
64B/66B PCS is defined in IEEE 802.3 Clause 49 and its Physical Medium Dependent PMD in Clause 52. It delivers serialized data at a line rate of 10.3125 Gbit/s.
10GBASE-ER has a reach of 40 kilometres (24.9 mi) over engineered links and 30 km over standard links.
10GBASE-ZR
Several manufacturers have introduced 80 km (49.7 mi) range ER pluggable interfaces under the name 10GBASE-ZR. This 80 km PHY is not specified within the IEEE 802.3ae standard and manufacturers have created their own specifications based upon the 80 km PHY described in the OC-192/STM-64 SDH/SONETSonet
Sonet may refer to:* Sonet Records, European record label* Synchronous optical networking * Saab Sonett...
specifications.
The 802.3 standard will not be amended to cover the ZR PHY.
10GBASE-LX4
10GBASE-LX4 is a port type for multi-mode fiber and single-mode fiber. It uses four separate laser sources operating at 3.125 Gbit/s and coarse WDM with four unique wavelengths around 1310 nm. Its Physical Coding SublayerPhysical Coding Sublayer
- Description :The Physical Coding Sublayer further helps to define physical layer specifications for networking protocols like Fast Ethernet, Gigabit Ethernet and 10 Gigabit Ethernet....
8B10B PCS is defined in IEEE 802.3 Clause 48 and its Physical Medium Dependent PMD in Clause 53.
It supports a range of 300 metres (984.3 ft) over FDDI-grade, OM1, OM2 and OM3 multi-mode cabling (all these fiber types are specified to have a minimum modal bandwidth of 500 MHz*km at 1300 nm).
10GBASE-LX4 also supports a range of 10 kilometres (6.2 mi) over SMF.
For MMF links the WDM output needs to be be coupled through a SMF offset-launch mode-conditioning patch cord. This is explained in subclauses 53.6 and 38.11.4 of the IEEE 802.3 spec.
Until 2005 10GBASE-LX4 optical modules were cheaper than 10GBASE-LR optical modules.
10GBASE-LX4 was used by people who wanted to support both MMF and SMF with a single optical module.
10GBASE-LX4 is now an obsolete technology and has no significant market presence.
Copper
10G Ethernet can also run over twin-axTwinaxial cabling
Twinaxial cabling, or "Twinax", is a type of cable similar to coax, but with two inner conductors instead of one. Due to cost efficiency it is becoming common in modern very-short-range high-speed differential signaling applications.-IBM:...
cabling, twisted pair
Twisted pair
Twisted pair cabling is a type of wiring in which two conductors are twisted together for the purposes of canceling out electromagnetic interference from external sources; for instance, electromagnetic radiation from unshielded twisted pair cables, and crosstalk between neighboring pairs...
cabling, and backplane
Backplane
A backplane is a group of connectors connected in parallel with each other, so that each pin of each connector is linked to the same relative pin of all the other connectors forming a computer bus. It is used as a backbone to connect several printed circuit boards together to make up a complete...
s.
10GBASE-CX4
10GBASE-CX4 — was the first 10G copper standard published by 802.3 (as 802.3ak-2004). It uses the XAUI 4-lane PCS (Clause 48) and copper cabling similar to that used by InfiniBandInfiniBand
InfiniBand is a switched fabric communications link used in high-performance computing and enterprise data centers. Its features include high throughput, low latency, quality of service and failover, and it is designed to be scalable...
technology. It is specified to work up to a distance of 15 m (49.2 ft). Each lane carries 3.125 G baud of signaling bandwidth.
10GBASE-CX4 offers the advantages of low power, low cost and low latency, but has a bigger form factor and more bulky cables than the newer single lane SFP+ standard and a much shorter reach than fibre or 10GBASE-T.
Shipments of 10GBASE-CX4 today are very low.
SFP+ Direct Attach
Also known as 10GSFP+Cu, 10GBase-CR, or 10GBase-CX1, SFP+ Direct Attach uses a passive twin-ax cable assembly and connects directly into an SFP+ housing. It has a range of 7 m 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+. SFP+ Direct Attach today is tremendously popular, with more ports installed than 10GBASE-SR.Backplane
Backplane Ethernet — also known by its task force name 802.3ap — is used in backplaneBackplane
A backplane is a group of connectors connected in parallel with each other, so that each pin of each connector is linked to the same relative pin of all the other connectors forming a computer bus. It is used as a backbone to connect several printed circuit boards together to make up a complete...
applications such as blade servers and routers/switches with upgradable line card
Line card
A line card or Digital Line Card is a modular electronic circuit on a printed circuit board, the electronic circuits on the card interfacing the telecommunication lines coming from the subscribers to the rest of the telecommunications access network.A line card commonly interfaces the twisted pair...
s. 802.3ap implementations are required to operate in an environment comprising up to 1 metres (39.4 in) of copper printed circuit board with two connectors. The standard defines two port types for 10 Gbit/s (10GBASE-KX4 and 10GBASE-KR) and a 1 Gbit/s port type (1000BASE-KX). It also defines an optional layer for FEC
Forward error correction
In telecommunication, information theory, and coding theory, forward error correction or channel coding is a technique used for controlling errors in data transmission over unreliable or noisy communication channels....
, a backplane autonegotiation protocol and link training for 10GBASE-KR where the receiver can set a three tap transmit equalizer. The autonegotiation protocol selects between 1000BASE-KX, 10GBASE-KX4, 10GBASE-KR or 40GBASE-KR4 operation. 40GBASE-KR4 is defined in 802.3ba.
New backplane designs use 10GBASE-KR rather than 10GBASE-KX4.
10GBASE-KX4
This operates over four backplane lanes and uses the same physical layer coding (defined in IEEE 802.3 Clause 48) as 10GBASE-CX4.10GBASE-KR
This operates over a single backplane lane and uses the same physical layer coding (defined in IEEE 802.3 Clause 49) as 10GBASE-LR/ER/SR.10GBASE-T
10GBASE-T, or IEEE 802.3an-2006, is a standard released in 2006 to provide 10 Gbit/s connections over unshielded or shielded twisted pairTwisted pair
Twisted pair cabling is a type of wiring in which two conductors are twisted together for the purposes of canceling out electromagnetic interference from external sources; for instance, electromagnetic radiation from unshielded twisted pair cables, and crosstalk between neighboring pairs...
cables, over distances up to 100 metres (328.1 ft). 10GBASE-T cable infrastructure can also be used for 1000BASE-T allowing a gradual upgrade from 1000BASE-T using autonegotiation to select which speed to use. 10GBASE-T has higher latency (1 microsecond) and consumes more power than other 10 gigabit Ethernet physical layers. As of 2010 10GBASE-T silicon is available from several manufacturers with claimed power dissipation of 3-4 W at structure widths of 40 nm. and with 28 nm in development, power will continue to decline.
Connectors
10GBASE-T uses the IEC 60603-7 8P8C (commonly known as RJ45) connectors already widely used with Ethernet. Transmission characteristics are now specified to .Cables
Category 6A or better balanced twisted pair cables specified in ISO 11801 amendment 2 or ANSI/TIA-568-C.2 are needed to carry 10GBASE-T up to distances of 100 m. Category 6 cableCategory 6 cable
Category 6 cable, commonly referred to as Cat 6, is a cable standard for Gigabit Ethernet and other network physical layers that is backward compatible with the Category 5/5e and Category 3 cable standards. Compared with Cat 5 and Cat 5e, Cat 6 features more stringent specifications for crosstalk...
s can carry 10GBASE-T for shorter distances when qualified according to the guidelines in ISO TR 24750 or TIA-155-A.
Electrical characteristics
The 802.3an standard defines the wire-level modulation for 10GBASE-T as a Tomlinson-Harashima precodedDirty paper coding
In telecommunications, dirty paper coding is a technique for efficient transmission of digital data through a channel subjected to some interference known to the transmitter...
(THP) version of pulse-amplitude modulation
Pulse-amplitude modulation
Pulse-amplitude modulation, acronym PAM, is a form of signal modulation where the message information is encoded in the amplitude of a series of signal pulses....
with 16 discrete levels (PAM-16), encoded in a two-dimensional checkerboard pattern known as DSQ128. Several proposals were considered for wire-level modulation, including PAM with 12 discrete levels (PAM-12), 10 levels (PAM-10), or 8 levels (PAM-8), both with and without Tomlinson-Harashima Precoding (THP). PAM-5 is what is used in the older 1000BASE-T gigabit Ethernet
Gigabit Ethernet
Gigabit Ethernet is a term describing various technologies for transmitting Ethernet frames at a rate of a gigabit per second , as defined by the IEEE 802.3-2008 standard. It came into use beginning in 1999, gradually supplanting Fast Ethernet in wired local networks where it performed...
standard.
WAN PHY (10GBASE-W)
The WAN PHY uses the 10GBASE-S, 10GBASE-L and 10GBASE-E optical PMDs and is designated as 10GBASE-SW, 10GBASE-LW or 10GBASE-EW. Its Physical Coding SublayerPhysical Coding Sublayer
- Description :The Physical Coding Sublayer further helps to define physical layer specifications for networking protocols like Fast Ethernet, Gigabit Ethernet and 10 Gigabit Ethernet....
64B/66B PCS is defined in IEEE 802.3 Clause 49 and its Physical Medium Dependent PMDs in Clauses 52. It also uses a WAN Interface Sublayer (WIS) defined in Clause 50 which adds extra encapsulation to format the frame data to be compatible with SONET STS-192c.
The WAN PHY was designed to interoperate with OC-192/STM-64 SDH/SONET
Sonet
Sonet may refer to:* Sonet Records, European record label* Synchronous optical networking * Saab Sonett...
equipment using a light-weight SDH/SONET frame running at 9.953 Gbit/s.
The WAN PHY is a niche product and rarely used.
10GbE NICs
10GbE network interface cards are available from several manufacturers. These plug into ordinary computer servers using PCI expressPCI Express
PCI Express , officially abbreviated as PCIe, is a computer expansion card standard designed to replace the older PCI, PCI-X, and AGP bus standards...
and connect to the LAN with a choice of PHY modules.
See also
- Energy Efficient EthernetEnergy Efficient EthernetEnergy-Efficient Ethernet is a set of enhancements to the twisted-pair and backplane Ethernet family of computer networking standards that will allow for less power consumption during periods of low data activity. The intention was to reduce power consumption by 50% or more, while retaining full...
- Fast EthernetFast EthernetIn computer networking, Fast Ethernet is a collective term for a number of Ethernet standards that carry traffic at the nominal rate of 100 Mbit/s, against the original Ethernet speed of 10 Mbit/s. Of the fast Ethernet standards 100BASE-TX is by far the most common and is supported by the...
- Gigabit EthernetGigabit EthernetGigabit Ethernet is a term describing various technologies for transmitting Ethernet frames at a rate of a gigabit per second , as defined by the IEEE 802.3-2008 standard. It came into use beginning in 1999, gradually supplanting Fast Ethernet in wired local networks where it performed...
- 100 Gigabit Ethernet100 Gigabit Ethernet40 Gigabit Ethernet, or 40GbE, and 100 Gigabit Ethernet, or 100GbE, are high-speed computer network standards developed by the Institute of Electrical and Electronics Engineers . They support sending Ethernet frames at 40 and 100 gigabits per second over multiple 10 Gbit/s or 25 Gbit/s lanes...
- List of device bandwidths
- GG45GG45The GG45 is a connector for high-speed Category 7 cable LAN cabling developed by Nexans.The cabling system was standardized in 2001 as IEC 60603-7-7, and then selected as a worldwide Category 7 cabling...
- TERATERATERA is a shielded twisted pair connector for use with Category 7 twisted-pair data cables, developed by The Siemon Company and standardized in 2003 by International Electrotechnical Commission 61076-3-104....
- XAUIXAUIXAUI is a standard for extending the XGMII between the MAC and PHY layer of 10 Gigabit Ethernet . XAUI is pronounced "zowie", a concatenation of the Roman numeral X, meaning ten, and the initials of "Attachment Unit Interface"...
- Optical interconnectOptical interconnectOptical interconnect is a way of communication by optical cables. Compared to traditional cables, optical wires are capable of a much higher bandwidth, from 10 Gb/s up to 100 Gb/s....
- Interconnect bottleneckInterconnect bottleneckThe interconnect bottleneck, the point at which integrated circuits reach their capacity, is expected sometime around 2010.Improved performance of computer systems has been achieved, in large part, by downscaling the IC minimum feature size. This allows the basic IC building block, the transistor,...
- Optical fiber cableOptical fiber cableAn optical fiber cable is a cable containing one or more optical fibers. The optical fiber elements are typically individually coated with plastic layers and contained in a protective tube suitable for the environment where the cable will be deployed....
- Optical communicationOptical communicationOptical communication is any form of telecommunication that uses light as the transmission medium.An optical communication system consists of a transmitter, which encodes a message into an optical signal, a channel, which carries the signal to its destination, and a receiver, which reproduces the...
- Parallel optical interfaceParallel optical interfaceA parallel optical interface is a form of fiber optic technology aimed primarily at communications and networking over relatively short distances , and at high bandwidths....
- 10G-PON10G-PON10G-PON is a 2010 computer networking standard for data links, capable of delivering shared Internet access rates up to 10 Gbit/s over existing passive optics. Passive optical network architecture has become a cost effective way to meet performance demands in access networks...
External links
- Full text of the IEEE 802.3 standard
- IEEE 802.3 Ethernet Working Group
- Ethernet Alliance website
- University of New Hampshire Interoperability Laboratory 10 Gigabit Ethernet Consortium
- First global independent comparative 3rd party UTP-STP sudy
- Description of SFP+ Direct Attach server NIC in top-of-rack concept