Transcript LIDO Next Generation Networks

LIDO Telecommunications Essentials®
Part 3
Next Generation Networks
Next Generation Networks
LIDO
1
The Broadband Evolution
• ICT trends are making a profound impact on life as we
know it.
• We're quickly becoming a world populated with things
that think.
• A new generation of converged infrastructure required
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bandwidth abundance
the use of intelligent optical networks
protocols that can guarantee performance in service levels
devices that can engage across a complete realm of voice,
data, video, rich media, and sensory media
– all on a mobile basis when needed.
LIDO
2
Broadband Drivers
• Primary drivers toward broadband infrastructures
include
– the increasing demand for information
– the shifting traffic patterns
• Today's key competitive edge is two-fold: it
includes both
– intellectual property
– the ability to develop and sustain relationships well
• To perform well in both of these aspects, you need
– An ongoing stream of the latest information
– Effective communications tools
LIDO – A next generation infrastructure
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Broadband Drivers
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Increasing demand for information
Shifting traffic patterns
Growing network usage
Rapid technology advances
Unleashing of bandwidth
Applications evolution
Convergence forces
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Communications Traffic Trends
• For a decade, the Internet demonstrated
tremendous growth rates.
• The average traffic is expected to range from
2Tbps to 3Tbps by 2008.
• The most important factor in the rate of traffic
growth going forward is likely to be the
growth of broadband subscribers.
LIDO
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Shifting Traffic Patterns
• Shift to machine-to-machine communications.
• Smart devices have communication capabilities.
• Things that think and talk require network access
and capacity.
• There will be thousands of such devices for each
human, not to mention an enormous array of
intelligent sensors monitoring each and every move
of the environment, of humans, and of animals.
LIDO
6
Communications Backbone Trends
• Growth and changes in traffic necessitate changes
in the network backbone.
• Pre-1995 Internet, backbone traffic was growing at
a compound rate of about 6% to 10% per year.
• Post-1995, traffic had been increasing at a
compound annual rate of more than 100%, slowing
for the first time in 2005.
• Today the average amount of traffic on the Internet
exceeds 1Tbps.
LIDO
7
Communications Backbone Trends
Application
Online virtual reality
3-D holography
Grid Computing
Web agents
Backbone Bandwidth
(Terabits per second)***
1,000 Tbps to 10,000 Tbps
30,000 Tbps to 70,000 Tbps
50,000 Tbps to 200,000 Tbps
50,000 Tbps to 200,000 Tbps
***1,000 Terabits per second = 1 Petabit per second
LIDO
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Communications Bandwidth Trends
• Technology breakthroughs, particularly in optical
systems, have had a profound impact on service
providers and bandwidth cost.
• As a result of the current growth in bandwidth
demand, additional capacity will be required.
– The demand may be met by activating currently unlit
wavelengths and fiber pairs, rather than new constuction
• On the other hand, new generations of high-speed
optical muxes, cross-connects and switches, will
require new generations of fiber optic cable.
LIDO
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Communications Bandwidth Trends
• Tremendous growth is also occurring in the wireless
realm.
– Wireless capacity is increasing
– The per-minute network costs are falling
– Data is accounting for more and more of the wireless
traffic
• High-speed wireless communications will be the
prevailing approach to Web access and between
components as well.
LIDO
10
Communications Bandwidth Trends
• What is the effect of broadband access on
core network capacity requirements?
• Broadband access lines put incredible stress
on the core network and will drive the
demand for more bandwidth in the core.
• Upgrades have to occur in parallel in order to
truly manifest the benefits of broadband
networking end-to-end.
LIDO
11
The Broadband Economy
• Much of the economic growth of the late 1990s is
attributed to productivity gains realized as a result of
new communications and IT products.
• According to PriceWaterhouseCoopers, workers
with broadband are 270% more productive than
workers using dial-up.**
• The greater the productivity of a country, the
stronger the economy.
LIDO
** Source: “A National Imperative: Universal Availability of Broadband by 2010”,
John Earnhardt, Cisco Government Affairs
http://newsroom.cisco.com/dlls/ts_011502.html
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Communications Applications Trends
• Growth of new generations of business class
services
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e-commerce, m-commerce
Virtual Private Networks (VPNs)
Voice over IP, Fax over IP
“Fee Quality” Voice (versus “free quality”)
Voice/audio portals
Unified messaging
Multimedia collaboration
Streaming media
Content delivery
Applications hosting
Network caching
Managed wavelength services
Customer management
• IMPACT - Business class communications require
guaranteed performance
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Communications Application Trends
• Transition from portables to wearables
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watches with medical monitors & pagers
eyeglasses with embedded computer displays
belts & watches with embedded computers
rings with Universal Product Code (UPC) reader & display
badge based cellphones & pagers with Internet
connections and tiny teleconferencing cameras
– RFID tags everywhere!
– Implants with healthcare, financial, security applications
• IMPACT - requires broadband wireless
infrastructure and personal area networks (PANs)
LIDO
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Communications Application Trends
• Evolution to new models of information
processing & communications
– Ubiquitous, or pervasive computing
– Human information processing model
– Multimodal & multisensual information flows
– Visualization
– Telepresence
– Augmentation, neural interfaces
– Virtuality
• IMPACT - requires tremendous bandwidth, low
latency, guaranteed performance and wireless
LIDO access
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Industries Benefiting from
Broadband Applications
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Entertainment
Education
Healthcare
Teleworking
National Security
and many many others……
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Broadband Applications
Entertainment
• Broadband introduces consumers to a range of new
entertainment technologies, including
– high-definition video over the Internet
– CD-quality Internet radio
– file sharing to enable swapping of home videos
and photographs
– web-based delivery of movies and large software
– sophisticated, realistic online games
• Broadband users are more likely than narrowband
users to download music, listen to music online,
watch video online, bank online, and trade stocks
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LIDO online.
Broadband Applications
Education
• Broadband applied to education enables
– interactive multimedia learning
– rich-media content delivery
– on-line testing
– sophisticated learning tools
– wireless campuses
– location and income independent education
• Result is that high-quality education can be brought
to those in need, including those living in rural or
remote locations, disadvantaged communities, and
developing countries.
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LIDO
Broadband Applications
Healthcare
• Broadband in healthcare has tremendous value
• enabling leading doctors to treat patients in the
most remote regions of the country
• helping to reduce costs and provide better services
to even the most rural and remote locations
• allowing wireless networks to support online
reporting and diagnostics, integrated with billing
• providing emergency services
• extend regular health care to homebound patients
LIDO
19
Broadband Applications
Teleworking
• Key applications include
– fast data access
– enhanced communications
– videoconferencing to remote locations
• Work more productively from remote locations
• Benefits include
– reducing traffic congestion, and affecting the investment
needed in reengineering the transportation grid
– alleviating pollution
– reducing dependence on foreign oil
– improving quality of life
– generating potentially enormous cost-savings
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LIDO
to our society
Broadband Applications
National Security
• Broadband is vital to providing an effective
national security system
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– Supports real-time interagency coordination,
monitoring and mobilization
– It is more resilient and reliable in the event of
disruption.
• Supports teleworking, allowing communications
and work to continue from remote locations in
event of disruptions
• Vital to battlefield logistics, data tracking, and
equipment maintenance
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Broadband Applications
Additional Sectors
• Retail
– Inventory, promotional, warehousing
• Field services
– Inventory, diagnostics, repair, maintenance
• Transportation
– Navigation, logistics, cargo management, virtual trips
• Mining
– Remote telemetry, remote drilling
• Oil
– Exploration, drilling, mapping
• The list is limited only by the imagination
LIDO
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The Human is a Multimedia
Information Processing System
Visualization improves physical and
intuitive understanding.
More than 50% of a human's brain
cells are devoted to processing visual
information.
The mind operates on sensations,
physical cues, to interpret and
create information for its own use.
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Auditory
Visual
Olfactory
Tactile
Kinetic
Digital rich-media will
increasingly depend on
multimedia.
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Per User Bandwidth Requirements
for New Services
• Email/Web (not optimum support)
56 Kbps
• Web is always-on utility, crude hosted apps,
15 sec video email
500 Kbps
• Hosted apps/reasonable videophone
5 Mbps
• Massive multiplayer/multimedia communities 10 Mbps
• Scalable NTSC/PAL-quality video
100 Mbps
• Digital video-on-demand
1 Gbps
• Innovation
10 Gbps
LIDO
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Multimedia Networking Requirements
• Digital video and digital audio require
– Minimal, predictable delays in packet transmission
– Tight control over losses
– Proper bandwidth allocation
• Conventional shared-bandwidth, connectionless
packet networks do not support these requirements.
• As more people simultaneously access files from a
server, bandwidth becomes a significant issue.
– Correct timing, synchronization, and video picture quality
are compromised if the bandwidth is not sufficient.
LIDO
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Evolution of Digital TV
• One of the fascinating areas driving and motivating
the need for broadband access is television.
• Despite major advances in computing, video, and
communications technologies, TV continued to rely
on standards that are more than 60 years old.
• These standards include
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– National Television Standards Committee (NTSC), used
in North America and Japan
– Phase Alternation Line (PAL), used throughout the
majority of the world
– Systeme Electronique Couleur Avec Memoire (SECAM),
used in France and French territories.
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Digital TV Advantages
• Digital TV (DTV) offers numerous advantages over
the old analog TV signal.
– It is nearly immune to interference and degradation.
– It has the ability to display over 16,000, 000 colors
– It can transmit more data and more types of data in the
same amount of bandwidth
• With HDTV and digital sound combined, the end
user benefits from
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a better picture
better sound
additional digital data
a more engaging experience
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Multimedia and DTV Drivers
• The television industry, content, entertainment, and
application worlds, will be increasingly important to
how the local loop develops.
• This is driving the need for
– more bandwidth to the home
– more bandwidth in the home
• It is also driving the need to deliver programming
and content on a mobile basis.
– This is yet another argument for fixed mobile
convergence (FMC).
LIDO
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Video Applications & Bandwidth
• Digital television requirements
– Digitized NTSC requires 166 Mbps
– Digitized PAL requires 199 Mbps
– HDTV requires 1.5 Gbps
• H.323 videoconferencing applications
– require 384 Kbps to 1.544 Mbps.
• Streaming video requires
LIDO
– 3 Mbps for low quality
– 5 Mbps for moderate
– 7 Mbps for high quality
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Video Applications & Bandwidth
• Content is an important driver behind
broadband access.
• It is an era of new revenue-generating
services enabled by personal digital
manipulation.
• We will need heaps more bandwidth
bandwidth into and in our homes to feed the
new generations of televisions.
LIDO
30
Television vs Video Definition
• Television has been associated with the concept of
delivery of someone else's programming on
someone else's timetable, whether by broadcast,
terrestrial or satellite, or cable networks.
• Video has been associated with the ability to record,
edit, or view programming on demand, according to
your own timetable and needs.
• Multimedia promises to expand the role of videoenabled communications, ultimately effecting a
telecultural shift.
LIDO
31
Digital Video Measurements
• Pixels = resolution
– the more pixels per screen, the greater, or better,
the resolution
• Frame rate = smoothness of motion
– The more frames per second, the smoother and
more natural the movement
• Bits per Pixel = color depth
– The more bits per pixel, the greater the range of
colors that can be displayed
LIDO
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Video Compression Basics
• To make the most of bandwidth, compression
must be applied to video.
– to fit into the precious spectrum allocated to
television and wireless networks
– to fit on most standard storage devices
• Moving Picture Experts Group (or MPEG) is
in charge of developing standards for coded
representation of digital audio and video.
LIDO
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MPEG Compression
• The MPEG compression algorithm reduces
redundant information in images.
• MPEG compression is asymmetric.
• Digital movies compressed using MPEG run faster
and take up less space.
• Key MPEG standards include
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MPEG-1
MPEG-2
MPEG-4
MPEG 4 AVC
MPEG-7
MPEG-21
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MPEG 1
• MPEG-1 is a standard for storage and retrieval of
moving pictures and audio on storage media.
• MPEG-1 is the standard on which such products as
Video CD and MP3 are based.
• MPEG-1 addresses VHS-quality images with a
– 1.5Mbps data transfer rate
– 352 x 240 resolution (quarter screen)
– 30 frames per second (30fps).
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MPEG-2
• MPEG-2 is
– a widely implemented video compression
scheme
– supports both interlaced and progressive scan
video streams
• MPEG-2 on DVD and DVB
– supports resolutions of 720x480 and 1280x720
– at up to 30 fps
– with full CD-quality audio.
• For MPEG-2 over ATSC
– resolutions of 1920x1080 are also supported
LIDO – at up to 60 fps
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MPEG-4
• MPEG-4, a standard for multimedia applications
• MPEG-4 enables objects to be manipulated and
made interactive through Web-like hyperlinks and/or
multimedia triggers.
• MPEG-4 is intended to expand the scope of
audio/visual content to include
– simultaneous use of both stored and real-time
components
– distribution from and to multiple endpoints
– the ability to reuse both content and processes
LIDO
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MPEG-4 AVC/H.264
• MPEG-4 Advanced Video Compression (or AVC),
also called Part 10 or ITU H.264, is a digital video
codec standard noted for achieving very high data
compression.
• AVC contains a number of new features that
– allow it to compress video much more effectively than
older standards
– make it applicable to a wide variety of network
environments
• Typically achieves the same quality as MPEG-2, but
at half the bit rate or less.
LIDO
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MPEG-7
• MPEG-7 is a multimedia content description
standard for information searching.
• It is not an audio or video compression or
encoding standard.
• It uses XML to store metadata and can be
attached to timecodes in order to tag
particular events, or, for example, to
synchronize lyrics to a song.
LIDO
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MPEG-21
• MPEG-21 provides a framework for the allelectronic creation, production, delivery, and trade
of content.
• The basic architectural concept in MPEG-21 is the
“digital item”.
• Digital items are structured digital objects, and are a
combination of
– resources (i.e., videos, audio tracks, images)
– metadata (such as MPEG-7 descriptors)
– structure (description of the relationship between
resources)
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MPEG Summary
• MPEG-1, MPEG-2, MPEG-4 and MPEG-4
AVC (H.264) primarily deal with content
coding
• MPEG-7 deals with providing descriptions of
multimedia content
• MPEG-21 provides a framework for the allelectronic creation, production, delivery, and
trade of content.
LIDO
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MPEG Summary
• Faster compression techniques using fractal
geometry and artificial intelligence are being
developed and could theoretically achieve
compression ratios of 2,500:1.
• This would enable full-screen, NTSC-quality video
to be delivered over LANs, the PSTN, and wireless
networks.
• Until better compression schemes are developed,
we have standardized on MPEG-2.
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MPEG Summary
• MPEG-2 is an industry standard for digital video for
DVDs and some satellite television services.
• However, MPEG-2 does have some recognized
disadvantages.
• One problem with MPEG-2 is that it is a lossy
compression method.
• This means that a higher compression rate results
in a poorer picture.
– There's some loss in picture quality between a digital
video camera and what you see on your TV.
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Windows Media 9
• Another important video compression technique is
Windows Media 9 (or WM9).
• WM9 is based on the VC-1 video codec specification
which provides for high-quality video for streaming
and downloading.
• VC-1 decodes high-definition video
– twice as fast as the H.264 (MPEG-4 AVC) standard
– while offering two to three times better compression than
MPEG-2
LIDO
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Video Bandwidth and
Broadband Access
• A 1.5Mbps connection over DSL or cable modem
cannot come close to carrying a 20Mbps DTV
signal.
• Broadband access alternatives will shift over time.
– we will need more fiber
– we will need that fiber closer to the home
– we will need much more sophisticated compression
techniques
• We will also need new generations of wireless
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– a combination of intelligent spectrum use and highly
effective compression
– support for the requisite variable QoS environment
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Video Compression Trends
Current
MPEG-2
2006
MPEG4/VC-1
2007
MPEG4/VC-1
2009
MPEG4/VC-1
Enhancements Improvements
Standard 2.5-3
Definition Mbps
1.5-2
Mbps
<1.5 Mbps <1.0 Mbps
High
15-19
Definition Mbps
10-12
Mbps
8-10 Mbps <7 Mbps
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Video Applications & Delay
• Bit errors can be fatal
– missing video elements, synchronization
problems, or complete loss of picture
• Delay can wreak havoc with video traffic
– delay, or latency, adds up with more switches and
routers in the network
• While video can tolerate a small amount of delay,
jitter causes distortion and unstable images.
• There should be as many priority queues as the
network has QoS levels.
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Television – A Brief History
• In 1945, the U.S. Federal Communications
Commission (or FCC) allocated 13 basic VHF
television channels
– thus standardizing the frequencies and allocating a
broadcast bandwidth of 4.5MHz
• The NTSC was formed in 1948 to define a
national standard for the broadcast signal itself.
• The standard for black-and-white television was
set in 1953 and ratified by the EIA as the RS-170
specification.
• Full-time network color broadcasting was
introduced
in
1964,
with
an
episode
of
Bonanza.
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National Television Standards Committee
(NTSC)
• NTSC defines a 4:3 aspect ratio.
• An NTSC color picture with sound
occupies 6MHz of frequency spectrum
• To transmit this signal digitally without
compression requires about 160Mbps.
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Phase Alternation Line
(PAL)
• PAL defines a 4:3 aspect ratio.
• An PAL color picture with sound
occupies 8MHz of frequency
spectrum.
• To transmit this signal digitally
without compression requires
about 200Mbps.
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Systeme Electronique Couleur
Avec Memoire (SECAM)
• Also referred to as Sequential
Couleur Avec Memoire
• SECAM defines a 4:3 aspect ratio.
• A SECAM color picture with sound
occupies 8MHz of frequency
spectrum.
• There are many variations of the
SECAM standard as well.
LIDO
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Digital Television (DTV)
• Digital TV (or DTV) represents the ongoing
convergence of broadcasting and computing.
• DTV makes use of digital modulation and
compression to broadcast audio, data, and video
signals to TV sets.
• The difference between analog TV and DTV is
profound in terms of picture quality as well as
special screen effects, such as multiple-windowed
pictures and interactive viewer options.
• The quality of DTV is almost six times better than
what analog TV offers, delivering up to 1,080 lines
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LIDO of resolution and CD-quality sound.
Digital TV
The real promise of DTV lies in
its huge capacity, and the ability
to deliver information equivalent
to that held on dozens of CDs.
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Television is a critical aspect of
convergence – on all fronts.
- devices
- applications
- fixed networks
- wireless networks
- service providers
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DTV Characteristics
• One main application of DTV is to carry more
channels in the same amount of bandwidth
– either 6MHz or 8MHz, depending on the standard in use
• The other key application is to carry high-definition
programming, known as HDTV.
• Many common analog broadcasting artifacts can be
eliminated.
• However, digital signals can also suffer from
artifacts.
• While analog TV may produce an impaired picture it
is still viewable, whereas DTV may not work at all in
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LIDO the same situation.
TV Aspect Ratios
4:3 Aspect Ratio
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16:9 Aspect Ratio
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Resolution and Pixels
Besides a wider screen, an HDTV
picture has more detail and crisper
images.
TV images are made up of pixels,
each of which is a tiny sample of video
information.
Each pixel is composed of three close
dots of color: red, green, and blue.
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On a standard TV screen each pixel
has a spectral range of about 16.8
million colors.
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Pixels and DTV
• HDTV uses smaller pixels.
• HDTV has 4.5 pixels in the area taken up by a
single pixel on standard NTSC TVs.
• The maximum resolution of an NTSC TV is a
display that is
– 720 pixels wide by 486 active lines
– total of 349,920 pixels.
• A high-end HDTV display is
– 1,920 pixels wide by 1,080 active lines
– Total of 2,073,600 pixels - six times more pixels than the
older NTSC resolution!
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DTV and Audio
• DTV improves the visual experience and sound
quality.
• HDTV broadcasts sound by using the dolby
digital/AC-3 audio encoding system.
• It can include up to 5.1 channels of sound
– 3 in front (left, center, and right)
– 2 in back (left and right)
– and a subwoofer bass for a sound you can feel (the .1
channel).
• Sound on DTV is CD quality.
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DTV and Service Bundles
• Service providers are increasingly interested in
providing service bundles.
• Triple play is a strategy that involves the delivery of
voice, data, and video.
• Quadruple play is a strategy that involves voice,
data, video, and wireless or mobile.
• The possible implementations of DTV include
terrestrial DTV, satellite DTV, cable DTV, and IPTV.
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Digital Terrestrial Television (DTT)
• A number of countries are in the process of deploying
digital terrestrial television (DTT), which offers a number of
advantages to various parties.
– Governments
• Stand to make money as well as propel the country forward
– Broadcasters
• Are enabled to fight growing competition from many sources
– Manufacturers
• Benefit from new equipment sales
– Consumers
• Look forward to exciting new programming
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DTV and Service Providers
• In the satellite TV market, DTV is largely used to
multiplex large numbers of channels, including pay
TV, onto the available bandwidth.
• For cable TV providers, the main advantage is
increased value and subsequently revenues.
– Depending on the choices an operator makes in
hardware and software, features such as TV guides,
program reminders, content censorship, interactive Webstyle content viewing, gaming, voting, and on-demand
services such as VOD can add significantly more value
and ultimately revenues.
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DTV and Service Providers
• The Internet is starting to be adapted for use with
DTV deployments as part of the triple or quadruple
play.
– IPTV represents a big step forward as a new approach to
distributing television programming.
• Telcos of all sorts, far and wide, are helping to lead
the way into the video space.
– Combined with voice and data services, telco TV is
expected to become serious business.
– Some analysts suggest that telcos' success will hinge on
video, which means there are many challenges ahead for
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telcos.
DTV and Service Providers
• HDTV is the compelling device at retailers and the
roadmap to the future, with IP driving it.
• Key issues need attention, including the integration
of billing support systems and operational support
systems.
• New compression technologies and a new
generation of set-top boxes will make a big
difference.
• The transformation is under way, but telcos must
have the right software, content streams, and
security provisions, and that will take a while.
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Mobile TV
• Mobile TV constitutes another new and fascinating
approach to distributing television programming and
entertainment content.
• Set-top boxes are not only becoming more
intelligent, they will also interact with other devices.
• It is important to keep in mind that not everyone
feels joyful about watching TV on a tiny little screen.
• Some feel the mobile phone is the most exciting
software platform in history.
• As a result, the simple mobile phone is morphing
into a futuristic entertainment system and the most
exciting new technology platform since the Internet.
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Digital TV Standards
• Initially, an attempt was made to prevent the
fragmentation of the global DTV market into
different standards.
• However, as usually seems to be the case, the
world could not reach agreement on one standard,
and as a result, there are several major standards
in existence today.
• These standards fall into two categories
– fixed reception
– mobile reception
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Digital Broadcasting Standards
• Fixed-reception digital broadcasting standards
include
– The U.S. Advanced Television Systems Committee
(ATSC)
– The European DVB-Terrestrial (DVB-T)
– The Japanese Integrated Services Digital Broadcasting
(ISDB)
– The Korean terrestrial Digital Media Broadcasting
(T-DMB)
• The most widely adopted standard worldwide is
DVB-T, with most countries having adopted it.
• Argentina, Canada, Mexico, and South Korea have
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LIDO followed the U.S. in adopting ATSC.
Digital Broadcasting Standards
• Digital Multimedia Broadcasting-Terrestrial (or
DMB-T) is the youngest major broadcast standard
and provides the best reception quality for the
power required.
• The DMB standard is derived from the Digital Audio
Broadcast (or DAB) standard that enjoys wide use
in Europe for radio broadcasts.
• DAB and DVB-T are the preferred Chinese
standards.
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Digital Broadcasting Standards
• T-DMB is currently used in Korea and Germany,
and trials are underway in France, Indonesia, and
Norway.
• A related Korean standard, S-DMB exists for
satellite television services, allowing for TV
reception over larger areas than can be served with
T-DMB.
• One such format being proposed by NHK of Japan
is Ultra High Definition Video (UHDV). UHDV
provides a resolution that is 16 times greater than
that of HDTV.
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68
Digital Broadcasting Standards
• As far as mobile standards go, DVB-Handheld
(DVB-H) is the selected standard in Europe, India,
Australia, and southeast Asia.
• North America also uses DVB-H, as well as the
MediaFlo standard proposed by Qualcomm.
• MediaFlo, used only in North America at this time,
supports relatively fast channel switching and uses
its own broadcast towers as well as available
bandwidth in the cellular network.
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69
Digital Broadcasting Standards
• Japan is adopting the ISDB-T Mobile Segment
standard.
• Korea is embracing T-DMB.
• China may follow DVB-H or something else, and for
the time being, it is unknown which standard South
America and Africa will follow.
• The mobile broadcast market is nascent, and many
developments are in store before a winner emerges
in this arena.
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70
Digital Broadcasting Standards
• As far as the broadband evolution goes, the
importance of entertainment content and DTV is
significant.
• One of the biggest issues in TV standards involves
how DTV images are drawn to the screen.
• There are two perspectives
– the broadcast TV world - interlacing
– the computer environment – progressive scanning
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71
Interlacing Technique
• Interlacing is a technique cameras use to take two
snapshots of a scene within a frame time.
– During the first scan, the camera creates one field of
video, containing even-numbered lines
– During the second scan, it creates another field of video,
containing the odd-numbered lines
• The fields are transmitted sequentially, and the
receiver reassembles them.
• This technique makes for reduced flicker and
therefore greater brightness on the TV receiver for
the given frame rate (and bandwidth).
• Interlacing is rough on small text, but moving
72
LIDO images look fine.
Progressive Scanning
• Progressive scanning is a method for displaying,
storing, or transmitting moving images in which the
lines of each frame are drawn in sequence.
• There are a number of advantages associated with
progressive scaning, such as a subjective
perception of an increased vertical resolution.
• Additional benefits include the absence of flickering
of narrow horizontal patterns, easier compression,
and simpler video processing equipment.
LIDO
73
ATSC Standards
• The ATSC, an international, nonprofit organization,
develops voluntary standards for DTV.
• The ATSC's DTV standards include high-definition
TV (or HDTV), enhanced-definition TV (or EDTV),
standard definition TV (or SDTV), data
broadcasting, multichannel surround-sound audio,
direct-to-home satellite broadcast, and interactive
television.
• The ATSC DTV standard has since been adopted
by the governments of Argentina, Canada, Mexico,
and South Korea.
LIDO
74
ATSC Standards
• The ATSC high-definition standard includes three
basic formats: HDTV, EDTV, and SDTV.
• Digital TVs often have a 16:9 widescreen format
and can display progressive-scan content.
• Each of these formats is defined by
–
–
–
–
–
LIDO
the number of lines per video frame
the number of pixels per line
the aspect ratio,
the frame repetition rate
the frame structure (that is, interlaced scan or progressive
scan)
75
ATSC Standards
• ATSC signals are designed to work on the same
bandwidth as NTSC or PAL channels, that is 6 MHz
for NTSC and 8 MHz for PAL.
• The video signals are compressed using MPEG-2.
• The modulation technique varies, depending on the
transmission method.
• In the case of terrestrial broadcasters, the technique
used is Vestigial Sideband 8 (or VSB 8).
• Because cable TV operators usually have a higher
signal-to-noise ratio (or SNR), they can use 16-VSB
or 256-QAM.
76
LIDO
ATSC Standards
• ATSC requires about half of the power for the same
reception quality, in absence of errors, as the more
widely used DVB-T standard, but it is more
susceptible to errors.
• One recognized limitation with ATSC is that unlike
DVB-T and ISDB-T, ATSC cannot be adapted to
changes in propagation conditions.
• However, despite ATSC's fixed transmission mode,
under normal conditions, it is still a very robust
waveform.
LIDO
77
DVB Standards
• Digital Video Broadcasting (or DVB) is a suite of
internationally accepted, open standards for DTV
maintained by the DVB Project.
• Formed in 1993, the DVB Project is responsible for
designing global standards for the global delivery of
DTV and data services.
• DVB standards are very similar to ATSC
standards—including MPEG-2 video compression,
packetized transport, and guidelines for a 1,920 x
1,080 HDTV format—but they provide for different
audio compression and transmission schemes. 78
LIDO
DVB Standards
• DVB embraces four main standards that define the
physical and data link layers of a distribution
system.
–
–
–
–
DVB-S and DVB-S2
DVB-C
DVB-T
DVB-H
• DVB-S is an open standard for digital video
broadcast over satellites, defined by ETSI and
ratified in 1994.
– DVB-S supports only MPEG-2 encoded video streams.
LIDO
79
DVB Standards
• DVB-S2 is also an open standard for digital video
broadcast over satellites, defined by ETSI and
ratified in 2005.
– DVB-S2 has improved quality over DVB-S and allows for
coded video in H.264 (MPEG-4 AVC) or VC-1 bitstreams.
• DVB-C is an open standard for digital video
transmission over cable that was defined by ETSI
and ratified in 1994.
• DVB-T, an open standard defined by ETSI and
ratified in 1997, is used as the de facto standard for
terrestrial TV broadcasts in many nations.
LIDO
– It supports only MPEG-2 compression.
80
DVB Standards
• The DVB-H standard is an adaptation of terrestrial
DVB that is optimized for mobile handheld devices.
• These four distribution systems vary in their
modulation schemes.
• DVB-T and DVB-H use Coded Orthogonal
Frequency Division Multiplexing (or COFDM)
• DVB-S uses Quadrature Phase Shift Keying
(QPSK)
• DVB-C uses QAM, especially 64-QAM.
LIDO
81
DVB-MHP
• The DVB Project has also designed an open
middleware system for DTV, called the DVBMultimedia Home Platform (or MHP).
• MHP enables the reception and execution of
interactive, Java-based applications on a TV set,
including applications such as e-mail, SMS,
information services, shopping, and games.
• In the United States, CableLabs has specified its
own middleware system called OpenCable
Applications Platform (OCAP), which is based on
MHP.
LIDO
82
ISDB Standards
• ISDB is the DTV and Digital Audio Broadcasting
(DAB) format that Japan has created to allow radio
and television stations there to convert to digital.
• ISDB incorporates five standards
–
–
–
–
ISDB-S for digital satellite TV
ISDB-T and ISDB-Tsb for digital terrestrial TV
ISDB-C for digital cable TV
2.6 GHz band for mobile broadcasting
• All these standards are based on MPEG-2 video
and audio coding and are capable of HDTV.
LIDO
83
ISDB Standards
• ARIB developed the ISDB-S standards to meet a
number of requirements, including HDTV capability,
interactive services, network access, and effective
frequency utilization.
• ISDB-S allows 51Mbps to be transmitted through a
single transponder, making it 1.5 times more
efficient than DVB-S, which can only handle a
bitstream of approximately 34Mbps.
• The ISDB-S system can carry two HDTV channels
using one transponder, along with other
independent audio and data.
LIDO
84
ISDB Standards
• ISDB-T specifies OFDM transmission with one of
four modulation schemes: QPSK, DQPSK, 16QAM, or 64-QAM.
– With ISDB-T, an audio program and TV for both fixed and
mobile reception can be carried in the same multiplex.
– ISDB-T can support HDTV on moving vehicles at over
100kph, and it can be received on mobile phones moving
at over 400kph.
• ISDB-Tsb refers to the terrestrial digital sound
broadcasting specification and is the same
technical specification as ISDB-T.
– ISDB-Tsb can also be used for mobile reception.
LIDO
85
ISDB Standards
• ISDB-C is the cable digital broadcasting
specification.
• ISDB-C supports terrestrial digital
broadcasting services over cable using the
OFDM scheme with a 6MHz channel.
– It employs 64-QAM modulation.
• The mobile broadcasting 2.6GHz band uses
Code Division Multiplexing (or CDM).
LIDO
86
DMB Standards
• Digital Multimedia Broadcasting (or DMB) is a new
concept in multimedia mobile broadcasting service,
converging broadcasting and telecommunications.
• It is a digital transmission system for sending data,
radio, and TV to mobile devices such as mobile
phones.
• DMB is likely to change the way broadcast media is
consumed, creating a new cultural trend.
• The move to DMB started in Korea.
LIDO
87
DMB Standards
• DMB is designed to broadcast TV and video to
mobile devices, and in conjunction with existing
DAB services, also both audio and data.
• DMB can be integrated wherever there is already a
DAB infrastructure.
• The Korean domestic Satellite-DMB (or S-DMB)
system, which operates via satellite facilities, is an
ITU-T standard.
• With S-DMB, signals transmitted by a satellite
directly can be received by subscribers on most
areas on the ground.
LIDO
88
S-DMB Standards
Ku-band
13.824 GHz to 13.883 GHz
Satellite
DMB Center
Program
Provider
Ku-band
12.214 GHz to 12.239 GHz
S-band
2.630 to 2.665 GHz
Mobile
Phone
w/DMB-S
Receiver
LIDO
Vehicular
Device
DMB-S
Receiver
Gap Filler
Base Stations
89
DMB Objectives
• The DMB industry is focusing on core technologies
that are essential for next-generation broadcasting,
such as intelligent broadcasting, telecom, and
broadcasting convergent services and interactive
DMB services.
• DMB will not only provide high-definition services
but also intelligent, personalized, realistic, and paid
services in addition to those converged with
telecommunications.
LIDO
90
The Broadband Infrastructure
• Data traffic is equal to or surpassing voice as the
most mission-critical aspect of the network.
• The undeniable appeal of interactive multimedia
signals the need for a convergent infrastructure that
offers minimum latencies.
• More human users, more machine users, and more
broadband access are all contributing to the
additional traffic.
• Established carriers and new startups are deploying
huge amounts of fiber-optic cable and broadband
wireless systems.
91
LIDO
The Broadband Infrastructure
• This new era of abundant capacity stimulates
development and growth of bandwidth-hungry
applications and demands service qualities that can
allow control of parameters such as delay, jitter, loss
ratio, and throughput.
• Bandwidth-intensive applications are much more
cost-effective when the network provides just-intime bandwidth management options.
• Next-generation networks will provide competitive
rates due to lower construction outlays and
operating costs.
LIDO
92
Broadband Service Requirements
•
•
•
•
•
•
High speed, high bandwidth – measured in Tbps
Bandwidth on demand
Bandwidth reservation
Isochronous support – timebounded information
Agnostic platforms – multiprotocol, multipurpose
Unicasting – streams from a single origination point
directly to a destination point
• Multicasting – streams from a single origination
point to multiple destination points
• Variable Quality of Service parameters
•
Guaranteed
service
levels
93
LIDO
Broadband Service Requirements
• A number of developments have been key to
allowing us to deliver on this set of requirements.
• One important area is photonics and optical
networking.
LIDO
– Erbium-Doped Fiber Amplifiers (EDFAs)
– Wavelength Division Multiplexing (WDM), Dense
Wavelength Division Multiplexing (DWDM), and Coarse
Wavelength Division Multiplexing (CWDM)
– new generations of high-performance fiber
– reconfigurable optical add/drop multiplexers (ROADMs)
– optical cross-connects
– optical switches and routers
94
– optical probes and network management devices
Broadband Service Requirements
• A number of broadband access technologies, both
wireline and wireless, have been developed to
facilitate next-generation networking.
• The IP Multimedia Subsystem (IMS), multiservice
core, edge, and access platforms, multiservice
provisioning platforms (MSPPs), and the MPLS
architecture, are all vital aspects of the next
generation network.
LIDO
95
Next Generation Networks
• A next-generation network is
– a high-speed packet- or cell-based network
– that is capable of transporting and routing a
multitude of services
– including voice, data, video, and multimedia
• It is a common platform for applications and
services that is accessible to the customer across
the entire network as well as outside the network.
LIDO
96
Next Generation Networks
• NGNs are designed for multimedia
communications, which implies
• broadband
• low latencies
• quality of service guarantees
• Worldwide infrastructure consists of
•
•
•
•
•
•
•
LIDO
fast packet switching
optical networking
multiservice core, intelligent edge
next generation telephony
video & multimedia elements
broadband access technologies
wireless broadband technologies
97
Next Generation Networks
• Next-generation networks stand to change how
carriers provision applications and services and
how customers access them.
• End-user service delivery from a single platform
provides many benefits
– It decreases time to market
– It simplifies the process of moves, adds, and changes
– It provides a unique connection point for service
provisioning and billing.
LIDO
98
Next Generation Networks
• Next-generation networks must be able to support the
most up-to-date transport and switching standards.
• They must also support advanced traffic management,
including
–
–
–
–
full configuration
provisioning
network monitoring
fault management capabilities
• In a next-generation network, it is important to be able
to prioritize traffic and to provide dynamic bandwidth
allocation for voice, data, and video services.
LIDO
99
NGNs and Convergence
• One of the central themes in next-generation
networks is the notion of convergence.
• Convergence is actually occurring in a number of
different areas.
• The concept behind convergence varies depending
on whether you're a service provider, an equipment
manufacturer, or an applications developer.
• In the end they all focus on one thing: bringing
together voice, data, and video to be happily
married at the network level, at the systems level, at
the applications level, and at the device level.
LIDO
100
Convergence in Transport
• Convergence in transport refers to voice, data, and
video traffic all sharing a common packet-based
network, generally based on IP at present.
• From the standpoint of a service provider,
convergence has to do with having one common
infrastructure, rather than each technology requiring
its own separate platform.
LIDO
101
Convergence in Systems
• To equipment manufacturers system convergence
means creating systems that allow voice, data, and
video traffic to all be commonly served through one
device.
• In the context of next-generation network
infrastructures, this most commonly refers to the
use of softswitches, also known as call servers.
• From the standpoint of an enterprise network, this
can also involve the use of IP PBXs at the customer
premise or a service provider making IP centrex
available to the enterprise.
LIDO
102
Convergence in Applications
• In the realm of applications, convergence refers to
the integration of voice, data, and video at the
desktop, mobile device, or in servers.
• Examples of this might include
–
–
–
–
–
LIDO
integrated messaging
instant messaging
presence management
real-time rich media e-learning and training products,
multimedia sales presentations, and a variety of
interactive programs, such as video games
103
Convergence - The Argument
• Cost reductions
– The price of delivering a packet on the backbone
has been dropping 45-50% per year.
– VoIP toll bypass saves money on international
calls.
• Improved user and ICT staff productivity
• Easier administration
LIDO
104
Convergence - The Argument
• The real value is in the applications
– There are many synergies between converged
transport, IP telephony, and converged
applications.
– As IM/presence merges with IP telephony, IP
telephony becomes just another converged
application.
– IM/presence applications which integrate voice,
data and video require converged transport
LIDO
105
Convergence and Regulatory Issues
• A converged network, based on IP, has a powerful
impact on regulatory models.
• Regulation has historically been different for voice,
broadcast, cable, etc.
• Current regulations are based on service
– Offer telephone service, telephone regulations apply
– Offer TV service, cable TV regulations apply
• IP breaks the vertical model traditionally used in
regulation
– How do you regulate with a converged network
• Introduces the consideration of a horizontal model
– Regulations would be applied to layers
LIDO
106
Converging Public Infrastructures
• The PSTN and the Internet are on the path to
convergence.
• There has been a steady, albeit slow, migration to
packet-based networks
– There are many networks running converged voice, data
and video over a common WAN infrastructure.
• Meanwhile, new developments stand to alter the
path of migration for all concerned.
– The optical era
• A new generation of networks are emerging.
LIDO
107
Converging Public Infrastructures
PSTN - Voice
Internet - Data
High-speed Multimedia Communications
Quality of Service
ATM/MPLS
LIDO
IntServ/DiffServ/MPLS
IP + Optical
GMPLS
108
Traditional Service Provider Environment
• Voice is regulated, data is not.
• Network optimized for voice.
• Controlling latency is easy; providing bandwidth is
harder. Bandwidth is at a premium.
• Dynamically sharing the same bandwidth for voice,
data and video requires some type of QoS.
• All carriers (and some enterprises) desire measured
use for network chargeback.
• Carriers need their own facilities to maintain control.
• Traditional carriers’ view - transport is their
business.
109
LIDO
Traditional Enterprise Environment
•
•
•
•
Main goal of enterprise networks is to link sites.
Network staff is divorced from website developers.
The network is managed as a cost center.
The network architecture consists of separate voice
and data networks.
• High availability in data networks is important, but it
is more important for voice.
• Network optimization is supported by predictable
traffic, predictable service providers and predictable
rates/tariffs.
• Private networks are the preferred network
110
LIDO infrastructure.
Contemporary Enterprise Environment
• Extranet communications considered as important
as the enterprise intranet.
• Networking staff works with website
hosting/operation and e-commerce linkages.
• The objective of network management is to manage
the network as an application-enabling
infrastructure.
• Network architecture consists of converged
voice/data applications and transport.
LIDO
111
Contemporary Enterprise Environment
• Data network availability is considered more
important than voice.
• Network optimization is difficult due to
unpredictable traffic, changing service
providers and changing pricing.
• Public networks and outsourcing are the
preferred network infrastructure.
LIDO
112
Contemporary
Service Provider Environment
• Regulatory changes required - in a converged
network, voice, data and video are all just bits.
• Future revenues will not come from voice, voice will
move to wireless, and may become “free”.
• The new network is optimized for IP traffic.
• Providing bandwidth is easy, ensuring low latency is
not.
• Optical bandwidth drives down the cost, and price,
of long-haul WAN transport.
LIDO
113
Contemporary
Service Provider Environment
• Lots of bandwidth beats the complexity of QoS-based
service levels.
• Usage-based chargeback is replaced by multiple flatrate service levels.
• The new environment consists of extensive
wholesaling and reselling of other carrier facilities.
• New Service Providers don’t want to be just a
transport business.
LIDO
114
Network Commonality in
Service Environments
• Growing commonality between Service Provider
and Enterprise network infrastructures
• Growing commonality between Service Provider
hosting sites and Enterprise data centers
• Both taking advantage of dark fiber, wavelength
services, and coarse wavelength division
multiplexing (CWDM)
• Both emphasize user service level management,
accounting, and rapid deployment
• IP and Ethernet becoming more pervasive in both
worlds
115
LIDO
NGN Origins
• The vision of Next Generation Networks was born
over 20 years ago within the Internet community.
• The NGN we know today was defined by the
emergence and growth of packet switching
networks, interconnected via gateways (routers).
• The original Internet vision assumed
– connectionless datagram transport
– best-effort packet delivery
– separation of service creation from transport
• Today, service providers need infrastructures
capable of supporting multimedia and real-time
116
LIDO content services.
Migration to NGNs
• The challenge today for telecom providers, both
wireline and wireless, involves
– the seamless migration of the circuit-switched
voice services onto an IP-based backbone
– while retaining all the traditional and important
capabilities of the PSTN
• There is a need for
– an IP telephony infrastructure
– access to the voice network features and
capabilities users have grown accustomed to
– particularly those features required by law
LIDO
117
NGN and Service Providers
• In response to the new reality, carriers, with the
participation of vendors and governments, are
working with an ITU Study Group on developing
their own interpretation of the Next Generation
Network.
• The main purpose of these efforts is to ensure the
integration and interoperability of IP networks with
the PSTN and mobile networks.
• Almost all providers now recognize the main goal is
to evolve their infrastructures to support multimedia
and content delivery services.
LIDO
118
NGN According to the ITU
• The ITU definition of a Next Generation Network
defines
– a packet-based network
– the ability to provide telecommunication services and
make use of multiple broadband, QOS-enabled transport
technologies
– an environment where service-related functions are
independent from underlying transport-related
technologies.
• It supports generalized mobility, which will allow
consistent and ubiquitous provisioning of services
to users.
LIDO
119
NGN According to the ITU
• The ITU NGN looks to support much more than
simple voice communications, and includes
services such as
–
–
–
–
–
Presence and instant messaging
Push-to-talk
Voice mail
Video
Other multimedia applications
• Realtime and streaming modes
LIDO
120
NGN and The Politics
• There are many industry observers that
believe the ITU NGN effort is an attempt for
the ITU to take back control of the Internet.
• There are equally strong views by carriers
and governments that the Internet is not
working well.
• This also suggests a highly controlled world,
one many of us may not feel comfortable in.
• There are arguments for both sides of the
121
LIDO issue.
NGN Service Provider Benefits
• Benefits for carriers choosing to implement a
NGN-based infrastructure include
– Recovering control
– QoS network features
– Ability to provide preferential treatment to their
own multimedia services
– Opportunity to create walled gardens
– Reduction of competition
LIDO
122
NGN - Key Infrastructure Elements
•
•
•
•
•
LIDO
IP Multimedia Subsystem (IMS)
Three-tiered broadband architecture
Multiservice core and edge
Quality of Service
MPLS (multi-protocol label switching)
architecture
123
Next Generation Networks
• From an architectural standpoint, the ITU’s
NGN relies heavily on the IP Multimedia
Subsystem (IMS) framework.
– IMS was originally developed by 3GPP for
3G/UMTS networks
– The 3GPP2 standards body is working on similar
standards for CDMA networks
• IMS has now been extended to cover wireline
networks as well.
LIDO
124
IP Multimedia Subsystem (IMS)
• IMS is a service infrastructure that relies on Session
Initiation Protocol (SIP) to establish and maintain
call control.
• IMS is an internationally recognized standard that
defines a generic architecture for offering VoIP and
other multimedia services in wireline and wireless
applications.
• By adopting SIP as the signaling protocol, service
providers have a standard that works well for both
voice and data.
LIDO
125
IP Multimedia Subsystem (IMS)
• IMS allows carriers to build a single and common IP
service infrastructure that is independent of the
access method.
• The IMS architecture offers a number of benefits
–
–
–
–
LIDO
enhanced person-to-person communications
improved interaction between media streams
improved service mobility
the ability of third-party developers and vendors to easily
create and integrate new solutions through well-defined
APIs and standards.
126
IMS Applications
• IMS applications include
– voice telephony
– video telephony
– multimedia streaming
– HTTP and TCP/IP browsing
– instant messaging
– file sharing
– Gaming
– push-to-talk/push-to-media
– presence-based services
LIDO
127
IMS Principles
• Four basic principles are associated with IMS
–
–
–
–
access independence
different network architectures
terminal and user mobility
extensive IP-based services.
• Gateways are used to accommodate older systems
such as circuit-switched telephone networks and
GSM cellular systems.
• IMS allows service providers and carriers to employ
a variety of underlying network architectures.
LIDO
128
IMS Protocols
• IMS creates a telephony-oriented signaling network
that overlays an underlying IP network.
• IMS utilizes Session Initiation Protocol (or SIP), with
specific extensions for IMS.
• An IMS network comprises many SIP proxy servers
that mediate all customer/user connections and
access to network resources.
• The aim of SIP is to provide the same functionality
as the traditional PSTN, but because of their end-toend design, SIP networks are much more powerful
and open to the implementation of new services.
LIDO
129
IMS Protocols
• Although IMS is SIP based, it includes enhancements
and exceptions to the SIP specification, particularly for
registration, authentication, and session policy.
• IMS uses DIAMETER rather than RADIUS for
authentication, taking advantage of DIAMETER's
additional support for charging and billing functions,
such as prepaid calling services.
• IMS also utilizes the Common Open Policy Services
(COPS) protocol for mobile operators to enforce
security and QoS policies across network elements.
LIDO
130
IMS Protocols
• IMS initially required the use of IPv6, but given the
number of transport networks using IPv4, this
requirement has been relaxed.
• IMS terminal devices are centrally and tightly
controlled.
• IMS assumes that each user is associated with a
home network, and it supports the concept of
roaming across other wired or wireless networks.
• IMS also includes a policy engine and an
authentication, authorization, and accounting (or
AAA) server for operator control and security.
LIDO
131
IMS Layers
Session
Layer
Application
Servers
Control
Layer
Call Session
Control Function
Transport
Layer
LIDO
PSTN,
Internet, IP,
Radio Networks
Transport
Network
132
IMS Architecture
Application Servers
Application
and Service
Layer
SCIM
MRFC
S-CSCF
HSS, SLF
I-CSCF
Control
Layer
HLR
BGCF
PDF
Radio
Area Networks
LIDO
P-CSCF
MRFP
MGW
MGCF
Internet
IP, MPLS
MGW
PSTN
Transport
and Access
Layer
133
Narrowband
and
IMS Standards
• The base IMS functionality was first defined in the
3GPP Release 5 (or R5) standards and was
optimized for use by GSM UMTS wireless networks.
• The second phase of IMS standards development
ended with the publication of 3GPP R6 standards.
– R6 adds support for SIP forking and multiway
conferencing and the group management capabilities
necessary for instant messaging and presence services.
– R6 also allows for interoperability between the IMS
variant of SIP and the IETF SIP standard, and adds
interworking with WLANs.
• 3GPP Release 7 (or R7) adds support for fixed
LIDO networks.
134
NGN Architecture
• In today's environment
– time-division and statistical multiplexers gather customer
traffic for additional circuit-based aggregation through a
stable hierarchy of switching offices
– overlay networks, such as X.25, Frame Relay, ATM, and
the Internet have created the need to internetwork
services
– cable, DSL, fiber, and wireless access options brought
their own high-density access aggregation devices into
the picture
• In the core, SDH/SONET transport has been
layered over DWDM, adding capacity and
producing a variety of vendor-specific switching,
LIDO routing, and management options.
135
Today’s Networks
END OFFICE
TANDEM
EDGE NETWORK
RAC
CORE
RAC
Class 5
Switch
DAC
DSLAM
PSTN
ATM / Frame Relay Switch
DAC
CMTS
Cable
Modem
Private Line
MUX
MUX
MUX
LIDO
Ethernet/ATM/IP Switch
HFC
Plant
DAC
SDH/Sonet
Ring ADM
ADM
Core
Router
Core
Switch
136
DWDM
DSL
Modem
Router/Switch
Edge Transport
DAC
OC- 192
Dial Modem
END OFFICE
Today’s Network
TANDEM
EDGE NETWORK
CORE
Frame Relay Edge Switch
ATM
ATM Edge Switch
Core
Switch
IP
IP Edge Router
LIDO
137
DWDM
Core
Router
OC- 192
Frame Relay
Edge Transport
ADM
SDH/Sonet
Ring ADM
Today’s Networks
• By building overlay networks and separating access
(edge) and transport (core) functions, carriers
manage to add capacity and new services without
disrupting existing services.
• The downside is that new services rarely use the
same provisioning, management and
troubleshooting systems as the old network.
• These operations and management costs can
amount to as much as 50% of the carrier’s total cost
to provide a service.
LIDO
138
Three-Tiered Multiservice Network
• Access switches
– Outer tier – delivers broadband to customer
– Associated with single user access
• Edge switches
– Second tier – protocol and data service integration
• concentrate traffic and prepare it for backbone
• voice/data gateways (circuit--to-packet network integration)
• provide policy-based services management
• Core switches
– Inner tier – handles transmission of ATM, IP or MPLS
traffic.
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Multi Service Network
Intelligent
Network
AIN, SS7
Voice and
ISDN Network
DSL
Voice
FTTx
Wireless
HFC
Access Node
PBX
LAN
IAD
Enterprise
Network
ATM
Switching
ATM
Multiservice
Edge
Multiservice
Edge
ATM /IP/MPLS
Optical Core
Backbone
Satellite
Network
Multiservice
Edge
IP
Switching
ATM
Switching
Multiservice
Edge
Media
Server Farm
ISP
Network
LIDO
Mobile
Network
Frame Relay
Network
Router-based
IP network
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Complexities With Single Purpose
Boxes
Access Routers
IP
LAN
Switch
IP
ATM
Switch
IP
Circuit
Emulation
Frame
Relay
ATM
ATM
Voice
Access Concentrator
SNA
FRAD
Voice
Over IP
Access Concentrator
LIDO
ATM
Frame Relay Switch
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Simplicity With Multi-Purpose
Switches
IP
Circuit Emulation
Voice Over Frame Relay
ATM
Voice Over IP
Frame Relay
WAN
Edge
Switch
OC-3 to OC-48c
SNA
Voice Over ATM
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Network Core Serves The Edges
IP
IP
IP and ATM
SNA
IP
Frame
Relay
Frame
Relay
LIDO
SNA
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Quality of Service
• Ability to provide different levels of service to differently
characterized traffic or traffic flows
• Basis for offering various classes of service to different
segments of end users
• This allows the creation of different pricing tiers that
correspond to the QoS level
• Needed to deploy voice or video services with data
• QoS definitions include
– network bandwidth
– user priority control
– controlling packet/cell loss
– controlling network traffic transit delay (end-to-end)
– controlling network traffic delay variation (jitter)
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What is MPLS?
• MPLS is a general purpose tunneling
mechanism
– Can carry IP and non-IP payloads
– Uses label switching to forward packets/cells thru
the network
– Can operate over any data-link layer
• MPLS separates the control plane from the
forwarding plane
LIDO
– Enables the IP control plane to run on devices
that cannot understand IP or recognize packet
boundaries
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What is MPLS?
• “MP” means it is multiprotocol.
– MPLS is an encapsulating protocol, it can
transport a multitude of other protocols.
• “LS” indicates that the protocols being
transported are encapsulated with a label that
is swapped at each hop.
– The labels are of local significance only – they
must change as packets follow a path – hence
the “switching” part of MPLS.
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IP vs MPLS
• Since IP is a connectionless protocol, it cannot
guarantee that network resources will be available.
• Additionally, IP sends all traffic between the same
two points over the same route.
• Without explicit control over route assignments, the
provider has no way to steer excess traffic over less
busy routes.
• One key difference between MPLS and IP is that
packets sent between two end points can take
different paths, based on different MPLS labels. 147
LIDO
How MPLS Works
• MPLS is connection-oriented and makes use
of Label Switched Paths (LSPs).
• MPLS tags or adds a label to IP packets so
they can be steered over the Internet along
predefined routes.
• MPLS also adds a label identifying the type of
traffic, path and destination.
• This allows routers to assign explicit paths to
various classes of traffic.
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VCI = Virtual Channel Identifier
VPI = Virtual Path Identifier
MPLS Label (i.e. VCI/VPI)
IP Packet
H
L
Packet Header
How MPLS Works
H
L
Label Attached
and Packet Forwarded
H
Label Read
and Packet Forwarded
MPLS Tunnel Label Switched Path (LSP)
Label Switch Router (LSR)
Node 2
Label Switch Router (LSR)
Node 1
LIDO
MPLS Tunnel LSP
VPN specific LSP
VPN specific LSP
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How MPLS Works
LDP establishes
label-to-destination
network mappings
Edge Label
Switching Router
LDP
Ingress edge LSR
receives a packet,
performs layer-3
value-added services,
and labels the packets
LSP
LDP
LSP
LDP
LDP
LSP
LSP
Edge Label
Switching Router
Egress edge LSR
removes the label
and delivers the packet
Core LSR switches the packet
using label swapping
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How MPLS Works
• MPLS can switch a frame from any kind of Layer 2
link to any other kind of Layer 2 link, without
depending on any particular control protocol.
• MPLS supports several types of label formats.
– On ATM hardware, it uses the well-defined Virtual
Channel Identifier (VCI) and Virtual Path Identifier
(VPI) labels.
– On Frame Relay hardware, it uses a Data-Link
Connection Identifier (DLCI) label.
– Elsewhere, MPLS uses a generic label, known as
a shim, which sits between Layers 2 and 3.
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LIDO
MPLS Label Stacking
• Another powerful attribute of MPLS is Label
Stacking.
• Label stacking allows LSRs (label switched router)
to insert an additional label at the front of each
labeled packet, creating an encapsulated tunnel
that can be shared by multiple LSPs (label switched
paths).
• At the end of the tunnel, another LSR pops the label
stack, revealing the inner label.
• An optimization in which the next-to-last LSR peels
off the outer label is known in IETF documents as
“penultimate hop popping”.
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LIDO
MPLS Stacks
The PE routers map ports to MPLS labels
to create Virtual Leased Lines
MPLS
Backbone
ATM/FR
Tunnel LSP
LER
LER
Ethernet
ATM/FR VLL
IP/PPP
Ethernet VLL
IP VLL
Tunnel
LSP
Single tunnel LSP between edge routers carries many services
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MPLS Summary
• MPLS adds two important elements to IP
– Virtual circuits
• Referred to as a Label Switched Path (LSP)
– Eliminates the need for encryption and a secure tunnel
– Provides security similar to that found in Frame Relay
– Capacity reservation
• Enables the support of Service Level Agreements (SLAs)
– Typical parameters include
• Packet loss of < 1%
• Round trip delay of < 55 to 70 msec
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MPLS Summary
• Constraint-based routing is superior to IP, basing
routing decisions on more than just a shortest path
calculation.
• Best way for service providers to provision VPNs
that meet customer service quality metrics.
• Permits ISPs to scale their networks and meet
traffic engineering requirements without having to
resort to ATM PVC overlay networks.
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MPLS Summary
• MPLS adds QoS and Virtual Tunnels
• MPLS provides a common control plane between
layer 2 and layer 3
• MPLS can support multiple layer 2 protocols
– Frame Relay, ATM, Ethernet
• MPLS provides layer 2 performance
– It’s a compromise between connectionless layer 3 and
connection-oriented layer 2
– Deterministic behavior
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MPLS Summary
• MPLS is the most effective way to integrate IP and
ATM in the same backbone network.
• Reduces the processing overhead in IP routers,
improving packet forwarding performance.
• Another way to provide QoS in network backbones,
competing or complementary, with DiffServ,
IntServ/RSVP, and ATM QoS.
• Solves N-squared route propagation problem in
large backbones where routers have to be
interconnected with a mesh of ATM or Frame Relay
virtual circuits.
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LIDO
MPLS Summary
• Major efforts are under way to adapt the control
plane of MPLS to direct the routing of not just LSRs
but an expanded universe of devices, including
optical switches and other optical elements.
• The same routing system can control optical paths
in the DWDM core, LSPs across the MPLS
backbone, and paths involving any IP routers at the
edge of the network.
• This is the realm of GMPLS.
• Whether with MPLS or GMPLS, service providers
can simplify their operational procedures, deliver
more versatile IP services, and, most importantly to
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LIDO customers, sign meaningful SLAs.
LIDO Telecommunications Essentials®
Next Generation Networks
Lili Goleniewski
The LIDO Organization, Inc.
www. telecomessentials.com
+1-415-457-1800
[email protected]
Skypes ID: lili.goleniewski
Telecom Essentials Learning Center
www.telecomessentials.com
LIDO
Copyright © 2007- The LIDO Organization, Inc.
All Rights Reserved
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