14-06-2009, 12:59 AM
10 GIGABIT ETHERNET
A SEMINAR REPORT
Submitted by
VIKASH MISHRA
in partial fulfillment of requirement of the Degree
of
Bachelor of Technology (B.Tech)
in
COMPUTER SCIENCE AND ENGINEERING
SCHOOL OF ENGINEERING
COCHIN UNIVERSITY OF SCIENCE AND TECHNOLOGY
KOCHI- 682022
AUGUST 2008Page 2
DIVISION OF COMPUTER SCIENCE AND ENGINEERING
SCHOOL OF ENGINEERING
COCHIN UNIVERSITY OF SCIENCE AND TECHNOLOGY
KOCHI-682022
Certificate
Certified that this is a bonafide record of the seminar entitled
10 GIGABIT ETHERNET
Presented by the following student
VIKASH MISHRA
of the VII semester, Computer Science and Engineering in the year 2008 in partial
fulfillment of the requirements in the award of Degree of Bachelor of Technology in
Computer Science and Engineering of Cochin University of Science and Technology.
Mr. V.Damodran
Dr. David Peter S.
Seminar Guide
Head of the Division
Date
age 3Acknowledgement
Many people have contributed to the success of this. Although a single sentence hardly
suffices, I would like to thank Almighty God for blessing us with His grace. I extend my
sincere and heart felt thanks to Dr. David Peter, Head of Department, Computer
Science and Engineering, for providing us the right ambience for carrying out this work. I
am profoundly indebted to my seminar guide, Mr. V.Damodran for innumerable acts of
timely advice, encouragement and I sincerely express my gratitude to her.
I express my immense pleasure and thankfulness to all the teachers and staff of the
Department of Computer Science and Engineering, CUSAT for their cooperation and
support.
Last but not the least, I thank all others, and especially my classmates who in one way or
another helped me in the successful completion of this work.
VIKASH MISHRAPage 4
ABSTRACT
Since its inception at Xerox Corporation in the early 1970s, Ethernet
has been the dominant networking protocol. Of all current networking
protocols, 10 Gigabit Ethernet builds on top of the Ethernet protocol, but
increases speed tenfold over Fast Ethernet to 10000 Mbps, or 10 gigabit per
second (Gbps). This protocol, which was standardized in august 2002,
promises to be a dominant player in high-speed local area network
backbones and server connectivity. Since10 Gigabit Ethernet significantly
leverages on Ethernet, customers will be able to leverage their existi0ng
knowledge base to manage and maintain gigabit networks.
The purpose of this technology brief is to provide a technical
overview of 10 Gigabit Ethernet. This paper discusses:
¢
The architecture of the Gigabit Ethernet protocol, including physical
interfaces, 802.3x flow control, and media connectivity options
¢
The 10 Gigabit Ethernet standards effort and the timing for Gigabit
Ethernet
¢
10 Gigabit Ethernet topologies
¢
Migration strategies to 10 Gigabit EthernetPage 5
i
TABLE OF CONTENTS
CHAPTER NO.
TITLE
PAGE NO.
LIST OF TABLES
iii
LIST OF FIGURES
iv
1.
EXECUTIVE SUMMARY¦¦¦¦¦¦¦¦¦¦¦¦¦¦1
2.
10 GIGABIT ETHERNET TECHNOLOGY¦¦¦¦¦...¦3
OVERVIEW
3.
10 GIGABIT ETHERNET ALLIANCE¦¦¦¦¦¦¦¦..4
4.
10 GIGABIT ETHERNET STANDARD¦¦¦¦¦¦...¦..5
5.
10 GIGABIT ETHERNET IN THE MARKET¦¦¦..¦¦ 7
PLACE
6.
INTEROPERABILITY DEMOS¦¦¦¦¦¦¦¦¦¦¦.10
7.
APPLICATION FOR 10 GIGABIT ETHERNET¦¦..¦... .12
7.1 10 GIGABIT ETHERNET IN METRO¦¦¦.¦¦....12
7.2 10 GIGABIT ETHERNET IN LOCAL¦¦¦.¦¦....13
AREA NETWORK
7.3 10 GIGABIT ETHERNET IN THE STORAGE¦¦¦14
AREA NETWORK
7.4 10 GIGABIT ETHERNET IN WIDE¦¦¦¦.¦.¦.15
AREA NETWORK
8.
USING FIBRE IN 10 GIGABIT ETHERNET¦¦¦¦......17
8.1 FIBRE¦¦¦¦¦¦¦¦¦¦¦¦¦¦¦...¦.¦17Page 6
ii
8.2 PHYSICAL MEDIA DEPENDENT (PMDS)¦¦..17
8.2.1 PHYSICAL LAYER¦¦¦¦¦¦¦¦....18
9.
10 GIGABIT ETHERNET TECHNOLOGY 10GB¦¦¦20
CHIP INTERFACES
10.
CONCLUSION¦¦¦¦¦¦¦¦¦¦¦¦¦¦¦¦.¦..22
REFRENCES¦¦¦¦¦¦¦¦¦¦¦¦¦¦¦¦¦.¦. 23Page 7
iii
LIST OF TABLES
SERIAL NO.
TITLE
PAGE NO.
1
PMDs THAT HAVE BEEN SELECTED TO MEET
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THE 802.3ae TASK FORCEâ„¢S DISTANCE
OBJECTIVESPage 8
iv
LIST OF FIGURES
SERIAL NO.
TITLE
PAGE NO.
1
THE ARCHITECTURAL COMPONENTS OF THE
6
802.3ae STANDARD
2
10 GIGABIT ETHERNET INTEROPERABILITY
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DEMONSTRATION
3
EXAMPLE OF 10 GIGABIT ETHERNET USE IN
12
MAN NETWORK
4
EXAMPLE OF 10 GIGABIT ETHERNET USE IN
13
LAN NETWORK
5
EAMPLE OF 10 GIGABIT ETHERNET USE IN
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STORAGE AREA NETWORK
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EXAMPLE OF 10 GIGABIT ETHERNET USE IN
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WAN APPLICATION
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CONCEPTUAL DIAGRAM OF PHYs AND PMDs
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8
XAUI FUNCTION AS AN EXTENDER INTERFACE
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BETWEEN MAC AND PCSPage 9
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1. EXECUTIVE SUMMARY
From its origin more than 25 years ago, Ethernet has evolved to meet the
increasing demands of packet-switched networks. Due to its proven low
implementation cost, its known reliability, and relative simplicity of installation and
maintenance, its popularity has grown to the point that today nearly all traffic on
the Internet originates or ends with an Ethernet connection. Further, as the demand
for ever-faster network speeds has grown, Ethernet has been adapted to handle
these higher speeds and the concomitant surges in volume demand that accompany
them.
The One Gigabit Ethernet standard is already being deployed in large
numbers in both corporate and public data networks, and has begun to move
Ethernet from the realm of the local area network out to encompass the metro area
network. Meanwhile, an even faster 10 Gigabit Ethernet standard is nearing
completion. This latest standard is being driven not only by the increase in normal
data traffic but also by the proliferation of new, bandwidth-intensive applications.
The draft standard for 10 Gigabit Ethernet is significantly different in
some respects from earlier Ethernet standards, primarily in that it will only function
over optical fiber, and only operate in full-duplex mode, meaning that collision
detection protocols are unnecessary. Ethernet can now step up to 10 gigabits per
second, however, it remains Ethernet, including the packet format, and the current
capabilities are easily transferable to the new draft standard.
In addition, 10 Gigabit Ethernet does not obsolete current investments in
network infrastructure. The task force heading the standards effort has taken steps
to ensure that 10 Gigabit Ethernet is interoperable with other networking
technologies such as SONET. The standard enables Ethernet packets to travel
across SONET links with very little inefficiency.Page 10
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Ethernetâ„¢s expansion for use in metro area networks can now be expanded
yet again onto wide area networks, both in concert with SONET and also end-to-
end Ethernet. With the current balance of network traffic today heavily favoring
packet-switched data over voice, it is expected that the new 10 Gigabit Ethernet
standard will help to create a convergence between networks designed primarily for
voice, and the new data centric networks.Page 11
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2. 10 GIGABIT ETHERNET TECHNOLOGY
OVERVIEW
The 10 Gigabit Ethernet Alliance (10GEA) was established in order to
promote standards-based 10 Gigabit Ethernet technology and to encourage the use
and implementation of 10 Gigabit Ethernet as a key networking technology for
connecting various computing, data and telecommunications devices. The charter of
the 10 Gigabit Ethernet Alliance includes:
¢
Supporting the 10 Gigabit Ethernet standards effort conducted in the IEEE
802.3 working group
¢
Contributing resources to facilitate convergence and consensus on technical
specifications
¢
Promoting industry awareness, acceptance, and advancement of the 10
Gigabit Ethernet standard
¢
Accelerating the adoption and usage of 10 Gigabit Ethernet products and
services
¢
Providing resources to establish and demonstrate multi-vendor
interoperability and generally encourage and promote interoperability and
interoperability events
¢
Fostering communications between suppliers and users of 10 Gigabit
Ethernet technology and productsPage 12
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3. THE 10 GIGABIT ETHERNET ALLIANCE
The purpose of the 10 Gigabit Ethernet proposed standard is to extend the
802.3 protocols to an operating speed of 10 Gbps and to expand the Ethernet
application space to include WAN links. This will provide for a significant increase
in bandwidth while maintaining maximum compatibility with the installed base of
802.3 interfaces, previous investment in research and development, and principles
of network operation and management.
In order to be adopted as a standard, the IEEEâ„¢s 802.3ae Task Force has
established five criteria that the new 10 Gigabit Ethernet P (proposed) standard
must meet:
¢
It must have broad market potential, supporting a broad set of applications,
with multiple vendors supporting it, and multiple classes of customers.
¢
It must be compatible with other existing 802.3 protocol standards, as well
as with both Open Systems Interconnection (OSI) and Simple Network
Management Protocol (SNMP) management specifications.
¢
It must be substantially different from other 802.3 standards, making it a
unique solution for a problem rather than an alternative solution.
¢
It must have demonstrated technical feasibility prior to final ratification.
¢
It must be economically feasible for customers to deploy, providing
reasonable cost, including all installation and management costs, for the
expected performance increase.Page 13
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4. THE 10 GIGABIT ETHERNET STANDARD
Under the International Standards Organizationâ„¢s Open Systems
Interconnection (OSI) model, Ethernet is fundamentally a Layer 2 protocol. 10
Gigabit Ethernet uses the IEEE 802.3 Ethernet Media Access Control (MAC)
protocol, the IEEE 802.3 Ethernet frame format, and the minimum and maximum
IEEE 802.3 frame size.
Just as 1000BASE-X and 1000BASE-T (Gigabit Ethernet) remained true
to the Ethernet model, 10 Gigabit Ethernet continues the natural evolution of
Ethernet in speed and distance. Since it is a full-duplex only and fiber-only
technology, it does not need the carrier-sensing multiple-access with collision
detection (CSMA/CD) protocol that defines slower, half-duplex Ethernet
technologies. In every other respect, 10 Gigabit Ethernet remains true to the
original Ethernet model.
An Ethernet Physical layer device (PHY), which corresponds to Layer 1 of
the OSI model, connects the media (optical or copper) to the MAC layer, which
corresponds to OSI Layer 2. Ethernet architecture further divides the PHY (Layer
1) into a Physical Media Dependent (PMD) and a Physical Coding Sublayer (PCS).
Optical transceivers, for example, are PMDs. The PCS is made up of coding (e.g.,
64/66b) and a serializer or multiplexing functions.
The 802.3ae specification defines two PHY types: the LAN PHY and the
WAN PHY (discussed below). The WAN PHY has an extended feature set added
onto the functions of a LAN PHY. These PHYs are solely distinguished by the
PCS. There will also be a number of PMD types.Page 14
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Figure 4.The architectural components of the 802.3ae standardPage 15
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5. 10 GIGABIT ETHERNET IN THE MARKETPLACE
The accelerating growth of worldwide network traffic is forcing service
providers, enterprise network managers and architects to look to ever higher-speed
network technologies in order to solve the bandwidth demand crunch. Today, these
administrators typically use Ethernet as their backbone technology. Although
networks face many different issues, 10 Gigabit Ethernet meets several key criteria
for efficient and effective high-speed networks:
¢
Easy, straightforward migration to higher performance levels without
disruption,
¢
Lower cost of ownership vs. current alternative technologies “ including
both acquisition and support costs
¢
Familiar management tools and common skills base
¢
Ability to support new applications and data types
¢
Flexibility in network design
¢
Multiple vendor sourcing and proven interoperability
Managers of enterprise and service provider networks have to make many
choices when they design networks. They have multiple media, technologies, and
interfaces to choose from to build campus and metro connections: Ethernet (100,
1000,and 10,000 Mbps), OC-12 (622 Mbps) and OC-48 (2.488 Gbps), SONET or
equivalent SDH network, packet over SONET/SDH (POS), and the newly
authorized IEEE 802 Task Force (802.17) titled Resilient Packet Ring.
Network topological design and operation has been transformed by the
advent of intelligent Gigabit Ethernet multi-layer switches. In LANs, core networkPage 16
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technology is rapidly shifting to Gigabit Ethernet and there is a growing trend
towards Gigabit Ethernet networks that can operate over metropolitan area
distances.
The next step for enterprise and service provider networks is the
combination of multi-gigabit bandwidth with intelligent services, leading to scaled,
intelligent, multi-gigabit networks with backbone and server connections ranging
up to 10 Gbps.
In response to market trends, Gigabit Ethernet is currently being deployed
over tens of kilometers in private networks. With 10 Gigabit Ethernet, the industry
has developed a way to not only increase the speed of Ethernet to 10 Gbps but also
to extend its operating distance and interconnectivity. In the future, network
managers will be able to use 10 Gigabit Ethernet as a cornerstone for network
architectures that encompass LANs, MANs and WANs using Ethernet as the end-
to-end, Layer 2 transport method.
Ethernet bandwidth can then be scaled from 10 Mbps to 10 Gbps “ a ratio
of 1 to 1000 †without compromising intelligent network services such as Layer 3
routing and layer 4 to layer 7 intelligence, including quality of service (QoS), class
of service (CoS), caching, server load balancing, security, and policy based
networking capabilities. Because of the uniform nature of Ethernet across all
environments when IEEE 802.3ae is deployed, these services can be delivered at
line rates over the network and supported over all network physical infrastructures
in the LAN, MAN, and WAN. At that point, convergence of voice and data
networks, both running over Ethernet, becomes a very real option. And, as TCP/IP
incorporates enhanced services and features, such as packetized voice and video,
the underlying Ethernet can also carry these services without modification.
As we have seen with previous versions of Ethernet, the cost for 10 Gbps
communications has the potential to drop significantly with the development of newPage 17
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technologies. In contrast to 10 Gbps telecommunications lasers, the 10 Gigabit
Ethernet short links †less than 40km over single-mode (SM) fiber †will be
capable of using lower cost, uncooled optics and, in some cases, vertical cavity
surface emitting lasers (VCSEL), which have the potential to lower PMD costs. In
addition, the industry is supported by an aggressive merchant chip market that
provides highly integrated silicon solutions. Finally, the Ethernet market tends to
spawn highly competitive start-ups with each new generation of technology to
compete with established Ethernet vendors.Page 18
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6. INTEROPERABILITY DEMOS
One of the keys to Ethernetâ„¢s success is the widespread interoperability
between vendors. In keeping with its mission to provide resources to establish and
demonstrate multi-vendor interoperability of 10 Gigabit Ethernet products, the 10
GEA hosted the worldâ„¢s largest 10 Gigabit Ethernet Interoperability Network in
May, 2002. The live, multi-vendor network was on display at the
NetWorld+Interop trade show in Las Vegas, Nevada. The network will also be on
display at SuperComm, June 4-7, 2002
in Atlanta Georgia.
Comprised of products from 23 vendors, the network included a
comprehensive range of products: systems, test equipment, components and
cabling. The end-to-end 10GbE network was over 200 kilometers long and
showcased five of the seven PMD port types specified in the IEEE 802.3ae draft:
10GBASE-LR, 10GBASE-ER, 10GBASE-SR 10GBASE-LW and 10GBASE-
LX4.The network boasted 10 network hops, 18 10 GbE links, and represented all
aspects of the technology; WAN, MAN and LAN.As part of the demonstration 12
companies showed chip-to-chip communication over the IEEE 802.3ae XAUI
interface.
The collection of products and technologies illustrate years of industry
collaboration and signal to the market that 10 Gigabit Ethernet is ready to be
deployed and implemented into networks around the world
.Page 19
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Figure 6.Worldâ„¢s Largest 10 Gigabit Ethernet Interoperability DemonstrationPage 20
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7. APPLICATIONS FOR 10 GIGABIT ETHERNET
7.1. 10 Gigabit Ethernet in the Metro
Vendors and users generally agree that Ethernet is inexpensive, well
understood, widely deployed and backwards compatible from Gigabit switched
down to 10 Megabit shared. Today a packet can leave a server on a short-haul optic
Gigabit Ethernet port, move cross-country via a DWDM (dense wave division
multiplexing) network, and find its way down to a PC attached to a thin coax
BNC (Bayonet Neill Concelman) connector, all without any re-framing or protocol
conversion. Ethernet is literally everywhere, and 10 Gigabit Ethernet maintains this
seamless migration in functionality.
Gigabit Ethernet is already being deployed as a backbone technology for
dark fiber metropolitan networks. With appropriate 10 Gigabit Ethernet interfaces,
optical transceivers and single mode fiber, service providers will be able to build
links reaching 40km or more. (as shown in fig7.1.)
Figure 7.1.An Example of 10 Gigabit Ethernet use in a MANPage 21
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7.2. 10 Gigabit Ethernet in Local Area Networks
Ethernet technology is already the most deployed technology for high
performance LAN environments. With the extension of 10 Gigabit Ethernet into the
family of Ethernet technologies, the LAN now can reach farther and support up
coming bandwidth hungry applications. Similar to Gigabit Ethernet technology, the
10 Gigabit proposed standard supports both single mode and multi-mode fiber
mediums. However in 10 Gigabit Ethernet, the distance for single-mode fiber has
expanded from the 5km that Gigabit Ethernet supports to 40km in 10 Gigabit
Ethernet.
The advantage for the support of longer distances is that it gives
companies who manage their own LAN environments the option of extending their
data centers to more cost-effective locations up to 40km away from their campuses.
This also allows them to support multiple campus locations within that 40km range.
Within data centers, switch-to-switch applications, as well as switch to server
applications, can also be deployed over a more cost effective multi-mode fiber
medium to create 10 Gigabit Ethernet backbones that support the continuous
growth of bandwidth hungry applications. (as shown in fig7.2.)
Figure 7.2.An Example of 10 Gigabit Ethernet use in a LANPage 22
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With 10 Gigabit backbones installed, companies will have the capability to
begin providing Gigabit Ethernet service to workstations and, eventually, to the
desktop in order to support applications such as streaming video, medical imaging,
centralized applications, and high-end graphics. 10 Gigabit Ethernet will also
provide lower network latency due to the speed of the page link and over-provisioning
bandwidth to compensate for the bursty nature of data in enterprise applications.
7.3. 10 Gigabit Ethernet in the Storage Area Network
Additionally, 10 Gigabit Ethernet will provide infrastructure for both
network-attached storage (NAS) and storage area networks (SAN). Prior to the
introduction of 10 Gigabit Ethernet, some industry observers maintained that
Ethernet lacked sufficient horsepower to get the job done. Ethernet, they said, just
doesnâ„¢t have what it takes to move dump truck loads worth of data. 10 Gigabit
Ethernet, can now offer equivalent or superior data carrying capacity at similar
latencies to many other storage networking technologies including 1 or 2 Gigabit
Fiber Channel, Ultra160 or 320 SCSI, ATM OC-3, OC-12 & OC-192,and HIPPI
(High Performance Parallel Interface). While Gigabit Ethernet storage servers, tape
libraries and compute servers are already available, users should look for early
availability of 10 Gigabit Ethernet end-point devices in the second half of 2001.
There are numerous applications for Gigabit Ethernet in storage networks
today, which will seamlessly extend to 10 Gigabit Ethernet as it becomes available.
(as shown in fig 7.3.) These include
age 2310 Gigabit Ethernet
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¢
Business continuance/disaster recovery
¢
Remote backup
¢
Storage on demand
¢
Streaming media
Figure 7.3.Use of 10 Gigabit Ethernet in Storage Area Networks
7.4. 10 Gigabit Ethernet in Wide Area Networks
10 Gigabit Ethernet will enable Internet service providers (ISP) and
network service providers (NSPs) to create very high-speed links at a very low cost,
between co-located, carrier-class switches and routers and optical equipment that is
directly attached to the SONET/SDH cloud. 10 Gigabit Ethernet with the WAN
PHY will also allow the construction of WANs that connect geographicallyPage 24
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dispersed LANs between campuses or POPs (points of presence) over existing
SONET/SDH/TDM networks. 10 Gigabit Ethernet links between a service
providerâ„¢s switch and a DWDM (dense wave division multiplexing) device or LTE
(line termination equipment) might in fact be very short †less than 300 meters. (as
shown in fig 7.4.)
Figure 7.4.Example of 10 Gigabit Ethernet in WAN ApplicationPage 25
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8. USING FIBRE IN 10 GIGABIT ETHERNET
8.1. FIBRE
There are two types of optical fiber, multimode and single-mode fiber, that are
currently used in data networking and telecommunications applications. The 10
Gigabit Ethernet technology, as defined in the IEEE 802.3ae* standard, supports
both optical fiber types. However, the distances supported vary based on the type of
fiber and wavelength (nm) is implemented in the application. In single-mode fiber
applications, the IEEE 802.3ae standard supports 10 km with 1310 nm optical
transmissions and 40 km with 1550 nm optical transmissions. With multimode
optical fiber, the distances are not as easily defined due to the variety of fiber types
and the way each type is defined. Multimode fiber is commonly defined by the core
and cladding diameters. For example, fiber with a core of 62.5 microns and a
cladding diameter of 125 microns is referred to as 62.5/125 micron fiber. The
acceptance of multimode fiber in networks today dates back to the inclusion of
62.5/125 micron fiber into the Fiber Distribution Data Interface (FDDI) standard in
the 1980s. The other portion that influences distance capabilities in multimode fiber
is the fiber information carrying capacity (measured in MHz-km), which
determines the distance and bit rate at which a system can operate (i.e., 1 Gbps or
10 Gbps). The distance a signal can run greatly decreases as transmission speed
increases (Table B). When implementing multimode fiber for 10 Gigabit Ethernet
applications, understanding the distance capabilities is a critical piece to the 10
Gigabit Ethernet solutions.
8.2. PHYSICAL MEDIA DEPENDENT
The IEEE 802.3ae Task Force has developed a draft standard that provides a
physical layer that supports page link distances for fiber optic media as shown in Table
8.2.Page 26
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To meet these distance objectives, four PMDs were selected. The task
force selected a 1310 nanometer serial PMD to meet its 2km and 10km single-mode
fiber (SMF) objectives. It also selected a 1550 nm serial solution to meet (or
exceed) its 40km SMF objective. Support of the 40km PMD is an
acknowledgement that Gigabit Ethernet is already being successfully deployed in
metropolitan and private, long distance applications. An 850 nanometer PMD was
specified to achieve a 65-meter objective over multimode fiber using serial 850 nm
transceivers.
Additionally, the task force selected two versions of the wide wave
division multiplexing (WWDM) PMD, a 1310 nanometer version over single-mode
fiber to travel a distance of 10km and a 1310 nanometer PMD to meet its 300-
meter-over-installedmultimode- fiber objective.
Table 8.2.PMDs that have been selected to meet the 802.3ae task forceâ„¢s
distance objectives
8.2.1. Physical Layer (PHYs)
The LAN PHY and the WAN PHY will operate over common PMDs and,
therefore, will support the same distances. These PHYs are distinguished solely by
the Physical Encoding Sublayer (PCS). (as shown in fig 7.4.) The 10 Gigabit LANPage 27
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PHY is intended to support existing Gigabit Ethernet applications at ten times the
bandwidth with the most cost-effective solution. Over time, it is expected that the
LAN PHY will be used in pure optical switching environments extending over all
WAN distances. However, for compatibility with the existing WAN network, the
10 Gigabit Ethernet WAN PHY supports connections to existing and future
installations of SONET/SDH (Synchronous Optical Network/ Synchronous Digital
Hierarchy) circuit-switched telephony access equipment.
The WAN PHY differs from the LAN PHY by including a simplified
SONET/SDH framer in the WAN Interface Sublayer (WIS). Because the line rate
of SONET OC-192/ SDH STM-64 is within a few percent of 10 Gbps, it is
relatively simple to implement a MAC that can operate with a LAN PHY at 10
Gbps or with a WAN PHY payload rate of approximately 9.29 Gbps. (as shown in
fig 8.2.1.). Appendix III provides a more in depth look at the WAN PHY.
Figure 8.2.1.Conceptual Diagram of PHYs and PMDsPage 28
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9. THE 10 GIGABIT ETHERNET TECHNOLOGY
10GBE CHIP INTERFACES
Among the many technical innovations of the 10 Gigabit Ethernet Task
Force is an interface called the XAUI (10 Gigabit Attachment Unit Interface). It is a
MAC-PHY interface, serving as an alternative to the XGMII (10 Gigabit Media
Independent Interface). XAUI is a low pin-count differential interfaces that enables
lower design costs for system vendors.
The XAUI is designed as an interface extender for XGMII, the 10 Gigabit
Media Independent Interface. The XGMII is a 74 signal wide interface (32-bit data
paths for each of transmit and receive) that may be used to attach the Ethernet MAC
to its PHY. The XAUI may be used in place of, or to extend, the XGMII in chip-to-
chip applications typical of most Ethernet MAC to PHY interconnects. (as shown in
fig 9.)
The XAUI is a low pin count, self-clocked serial bus that is directly
evolved from the Gigabit Ethernet 1000BASE-X PHY. The XAUI interface speed
is 2.5 times that of 1000BASE-X. By arranging four serial lanes, the 4-bit XAUI
interface supports the ten-time data throughput required by 10 Gigabit Ethernet.Page 29
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Figure 9.XAUI functions as an extender interface between the MAC and PCSPage 30
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10. CONCLUSION
As the Internet transforms longstanding business models and global
economies, Ethernet has withstood the test of time to become the most widely
adopted networking technology in the world. Much of the worldâ„¢s data transfer
begins and ends with an Ethernet connection. Today, we are in the midst of an
Ethernet renaissance spurred on by surging E-Business and the demand for low cost
IP services that have opened the door to questioning traditional networking dogma.
Service providers are looking for higher capacity solutions that simplify and reduce
the total cost of network connectivity, thus permitting profitable service
differentiation, while maintaining very high levels of reliability.
Enter 10 Gigabit Ethernet. Ethernet is no longer designed only for the
LAN. 10 Gigabit Ethernet is the natural evolution of the well-established IEEE
802.3 standard in speed and distance. It extends Ethernetâ„¢s proven value set and
economics to metropolitan and wide area networks by providing:
¢
Potentially lowest total cost of ownership (infrastructure/operational/human
capital)
¢
Straightforward migration to higher performance levels
¢
Proven multi-vendor and installed base interoperability (Plug and Play)
¢
Familiar network management feature set
An Ethernet-optimized infrastructure build out is taking place. The metro
area is currently the focus of intense network development to deliver optical
Ethernet services. 10 Gigabit Ethernet is on the roadmaps of most switch, router
and metro optical system vendors to enable:
¢
Cost effective Gigabit-level connections between customer access gear and
service provider POPs (points of presence) in native Ethernet format
¢
Simple, very high speed, low-cost access to the metro optical infrastructure
¢
Metro-based campus interconnection over dark fiber targeting distances of
10/40km and greaterPage 31
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¢
End to end optical networks with common management systemsPage 32
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REFERENCES
[1] IEEE P802.3ae 10Gb/s Ethernet Task Force
[2] IEEE LAN/MAN Standards Committee
[3] IEEE 802.3 CSMA/CD (ETHERNET)
[4] http://10gea
[5] http://standards.ieeeresources/development/index.html
[6] http://grouper.ieeegroups/802/3/ae/index.html
[7]http://ciscoen/US/tech/tk389/tk214/tk277/tsd_technology_sup
pors_sub-protocol_home.html
