OPTICAL NETWORKSOPTICAL NETWORKS

CONTENTS CONTENTS

1. History of Optical Networks1. History of Optical Networks2. About Optical fiber.2. About Optical fiber.3. Synchronous Optical Network3. Synchronous Optical Network4. SONET Features4. SONET Features5. When Is a Separate SONET LAYER Needed?5. When Is a Separate SONET LAYER Needed?6. SONET Network Elements6. SONET Network Elements7. SONET Network Configurations7. SONET Network Configurations8. SONET Benefits8. SONET Benefits9. Conclusions9. Conclusions10.Bibliography10.Bibliography

OPTICAL NETWORKSOPTICAL NETWORKS

Definition:Definition:

Optical networks are high-capacity Optical networks are high-capacity telecommunication networks based on telecommunication networks based on optical technologies and components that optical technologies and components that provide routing, and restoration at the provide routing, and restoration at the wavelength level as well as wavelength-wavelength level as well as wavelength-based services based services

overviewoverview

As networks face increasing bandwidth demand, so As networks face increasing bandwidth demand, so network providers are moving towards optical network.network providers are moving towards optical network.

It provides higher capacity and reduced costs It provides higher capacity and reduced costs

for new applications like as the internet, video and for new applications like as the internet, video and multimedia interaction and advanced digital services.multimedia interaction and advanced digital services.

History of Optical NetworksHistory of Optical Networks

In the early 1980s, a revolution in In the early 1980s, a revolution in telecommunications networks began & Since the telecommunications networks began & Since the tremendous cost savings and increased network tremendous cost savings and increased network quality has led to many advances in the quality has led to many advances in the technologies required for optical networks technologies required for optical networks

Throughout this history, the digital network has Throughout this history, the digital network has evolved in three fundamental stages: evolved in three fundamental stages: asynchronous, synchronous, and opticalasynchronous, synchronous, and optical

AsynchronousAsynchronous

pertaining to a transmission technique that pertaining to a transmission technique that does not require a common clock between does not require a common clock between the communicating devices.the communicating devices.

The first digital networks were The first digital networks were asynchronous networks.asynchronous networks.

Bit errors.Bit errors. Difficult to interconnectDifficult to interconnect

SynchronousSynchronous

pertaining to a transmission technique that pertaining to a transmission technique that requires a common clock signal between requires a common clock signal between the communicating devices in order to the communicating devices in order to coordinate their transmissionscoordinate their transmissions

The need for optical standardsThe need for optical standards SONET standardized line rates, coding SONET standardized line rates, coding

schemes, bit rate hierarchies, and schemes, bit rate hierarchies, and operations & maintenance functionality.operations & maintenance functionality.

About OpticalAbout Optical Fiber Fiber What is fiber optics?What is fiber optics? What is optical networking?What is optical networking? The main components of a fiber optic system includeThe main components of a fiber optic system include TransmitterTransmitter Fiber optic cableFiber optic cable Receiver Receiver Fiber optic cable: what is it and what types are there?Fiber optic cable: what is it and what types are there?

Inside an optical fiberInside an optical fiber1) Core1) Core

2) Cladding 2) Cladding 3) Coating 3) Coating

Types of fiberTypes of fiber1.multi mode1.multi mode

2. single mode 2. single mode

SONET/SDHSONET/SDH

Definition Definition

Synchronous optical network (SONET) is a Synchronous optical network (SONET) is a standard for optical telecommunications standard for optical telecommunications transport.transport.

SONET standard is expected to provide the SONET standard is expected to provide the transport infrastructure for worldwide transport infrastructure for worldwide telecommunications for at least the next telecommunications for at least the next two or three decades.two or three decades.

SONET FeaturesSONET Features

Network managementNetwork management

Bandwidth managementBandwidth management

Network simplificationNetwork simplification

When Is a Separate SONET When Is a Separate SONET LAYER Needed?LAYER Needed?

Reliable transmissionReliable transmission Ultra fast protection mechanismsUltra fast protection mechanisms Fastest transmission speedsFastest transmission speeds Long-distance transmissionLong-distance transmission multiplexing scalability (1.5 Mbps to 10 multiplexing scalability (1.5 Mbps to 10

Gbps)Gbps) Global ReachGlobal Reach

Some possible TopologiesSome possible Topologiesfor a SONET point to point Networkfor a SONET point to point Network

Mesh TopologyMesh Topology Star TopologyStar Topology Ring TopologyRing Topology

Mesh TopologyMesh Topology Advantages:Advantages:

Few Traffic ProblemsFew Traffic Problems Robust to FailuresRobust to Failures Privacy and SecurityPrivacy and Security

Disadvantages:Disadvantages: Cabling is ExpensiveCabling is Expensive

Figure from: Figure from: http://www.webopedia.com/TERM/t/topology.htmlhttp://www.webopedia.com/TERM/t/topology.html

Star TopologyStar Topology

Advantages:Advantages: Less Expensive (Cabling)Less Expensive (Cabling) Robust to Link FailuresRobust to Link Failures

Disadvantages:Disadvantages: Less SecureLess Secure Central Point of Failure Central Point of Failure

(Hub)(Hub)

Figure from: Figure from: http://www.webopedia.com/TERM/t/topology.htmlhttp://www.webopedia.com/TERM/t/topology.html

Ring TopologyRing Topology

Advantages:Advantages: SimplicitySimplicity

Disadvantages:Disadvantages: Lack of topological node degreeLack of topological node degree

Figure from: Figure from:

http://www.webopedia.com/TERM/t/topology.htmlhttp://www.webopedia.com/TERM/t/topology.html

SONET BenefitsSONET Benefits

improved servicesimproved services Survivable networkSurvivable network reduced operating costreduced operating cost centralized managementcentralized management reduced capital investmentreduced capital investment

ConclusionsConclusions

Continued advancements in optical Continued advancements in optical technology promise continued change as the technology promise continued change as the optical network evolves to the ultimate goal of optical network evolves to the ultimate goal of end-to-end wavelength services. end-to-end wavelength services.

Consumers will have access to new high-Consumers will have access to new high-bandwidth services made possible by the bandwidth services made possible by the increased capacity afforded by the optical increased capacity afforded by the optical layer. layer.

ReferenceReference

SONETSONET, Walter J. Goralski, McGraw-Hill Series on Computer , Walter J. Goralski, McGraw-Hill Series on Computer CommunicationsKathy Benninger, Pittsburgh SuperComputing CommunicationsKathy Benninger, Pittsburgh SuperComputing CenterCenter

Leo Donnelly, Harvard UniversityLeo Donnelly, Harvard University Mark Johnson, North Carolina Research & Education NetworkMark Johnson, North Carolina Research & Education Network Ron Hutchins, Georgia Institute of Technology/Southern Crossroads Ron Hutchins, Georgia Institute of Technology/Southern Crossroads

(SoX)(SoX) Sarah Morford, Grant County Public Utility DistrictSarah Morford, Grant County Public Utility District John Nichols, Virginia TechJohn Nichols, Virginia Tech Ana Preston, University of TennesseeAna Preston, University of Tennessee John Streck, North Carolina State UniversityJohn Streck, North Carolina State University Troy Travis, University of South CarolinaTroy Travis, University of South Carolina Bill Wing, Oak Ridge National LaboratoryBill Wing, Oak Ridge National Laboratory

THANK YOUTHANK YOU