3 - Hotz-Globalcrossings Fiber & Long Lines

8/3/2019 3 - Hotz-Globalcrossings Fiber & Long Lines

1/58

National Communications System

(NCS)

Fiber Optic Networks

National Communications System

(NCS)

Fiber Optic Networks

Dave Hotz

Director of Systems Installation andTransmission Support

Jim Chaney

Director of Field Operations Central

and West

Global CrossingGlobal Crossing


2/58

Fiber CableFiber Cable


3/58

Fiber Has More CapacityFiber Has More Capacity

This single fiber

can carry morecommunications

than the giant

copper cable!


4/58

Fiber Optic CableFiber Optic Cable

Protects the fibers

wherever they are

installed May have 1 to over

1000 fibers


5/58

Fiber Optic ConnectorsFiber Optic Connectors

Terminates the fibers

Connects to other fibers or

transmission equipment


6/58

Fiber Optic CommunicationsFiber Optic Communications

Applications include

Telephones

Internet

LANs - local area networks

CATV - for video, voice and Internet connections

Utilities - management of power grid

Security - closed-circuit TV and intrusion sensors

Military - everywhere!


7/58

What Is Fiber Optics ?What Is Fiber Optics ?

Transmittingcommunicationssignals over hair thin

strands of glass orplastic

Not a "new"technology

Concept a century old Used commercially for

last 25 years


8/58

Why Use Fiber Optics?Why Use Fiber Optics?

Economics

Speed

Distance

Weight/size

Freedom from interference

Electrical isolation

Security


9/58

Fiber Optic ApplicationsFiber Optic Applications

Fiber is already used in:

> 90% of all long distance telephony

> 50% of all local telephony

Most CATV networks

Most LAN (computer network) backbones

Many video surveillance links


10/58

Fiber Optic ApplicationsFiber Optic Applications

Fiber is the least expensive, most reliable

method for high speed and/or long distance

communications While we already transmit signals at Gigabits

per second speeds, we have only started to

utilize the potential bandwidth of fiber


11/58

Fiber TechnologyFiber Technology


12/58

Fiber TechnologyFiber Technology


13/58

Fiber Optic Data LinksFiber Optic Data Links


14/58

Light Used In Fiber OpticsLight Used In Fiber Optics

Fiber optic systems transmit using

infrared light, invisible to the human

eye, because it goes further in the

optical fiber at those wavelengths


15/58

Wavelength-Division

Multiplexing

Wavelength-Division

Multiplexing


16/58

What is SONET?What is SONET?

Synchronous Optical Network standard

Defines a digital hierarchy of synchronous signals

Maps asynchronous signals (DS1, DS3) to synchronous format

Defines electrical and optical connections between equipment

Allows for interconnection of different vendors equipment

Provides overhead channels for interoffice OAM&P

SONETNetworkElement

SONETNetworkElement

DigitalTributaries

DigitalTributaries


17/58

Digital Signal HierarchiesMost Common Rates

Digital Signal HierarchiesMost Common Rates

Asynchronous

SONETVT1.5(1.7 Mb/s)

STS-3(156 Mb/s)

STS-12(622 Mb/s)

STS-48(2500 Mb/s)

28 84 336 1344

Capacity

(DS-1 Equiv)

DS-1(1.544 Mb/s)

STS-1(52 Mb/s)

[Non-Standardized]

STM-1 STM-4 STM-16 SDH

DS-0(64 Kb/s)

VC-11 VC-3

DS: Digital Signal

SONET: Synchronous Optical NETwork (US)

SDH: Synchronous Digital Hierarchy (ITU)

STS: Synchronous Transport Signal

STM: Synchronous Transfer Mode

VC: Virtual Container

VT: Virtual Tributary

DS-3(45 Mb/s)


18/58

SONET RatesSONET Rates

STS-1 OC-1 51.840

STS-3 OC-3 155.520

STS-12 OC-12 622.080

STS-48 OC-48 2,488.320

STS-192 OC-192 9,953.280

LevelOptical

DesignationBit Rate(Mb/s)

STS = SYNCHRONOUS TRANSPORT SIGNALOC = OPTICAL CARRIER

(..result of a direct optical conversions of the STS aftersynchronous scrambling - ANSI)


19/58

SONET Network LayersSONET Network Layers

DS3

etc

DS3

etc

Path Map Services & POH Into SPE Path Protection/Restoration

Other Path OA&M Functions

Line Combine SPE & LOH Sync & Mux For Path Layer

Line Protection/Restoration

Other Line OA&M Functions

Section Add SOH & Create STS Signal Framing, Scrambling

Section OA&M Functions

Physical

(Photonic)

E/O Conversion

Line Code Physical Signal[No additional overhead]

MUX LTE Regen MUXLTELTERegen

Services

DS3, DS1, etc

SONET ADM

Path

Line Line

SectionSection Section Section


20/58

Functional Description of SONET

Layers

Functional Description of SONET

Layers

OH: Overhead

Path Layer

Line Layer

Section

Layer

Photonic

Layer

Information

Payload

Path

OH

LineOH

Section

OH

E/O Conversion

Transmission over OC-N

FunctionPayload MappingError Monitoring

SynchronizationMultiplexingError MonitoringLine MaintenanceProtection SwitchOrder Wire

FramingScramblingError MonitoringSection MaintenanceOrderwire

E/O ConversionPulse ShapingPower LevelWavelength


21/58

SONET ConfigurationsSONET Configurations


22/58

Generic SONET Network

Elements

Generic SONET Network

Elements

o

oo

o

oo

STS-N

Ports

STS-N

Ports

STS-M

Fabric

(M


23/58

Key SONET ConfigurationsKey SONET Configurations

48 W

48 P

PointTo

Point

Compatible With OLS

2 Nodes Per System

All T3s Use DACS III

1x1 Protection Switching

Compatible With OLS

2 To 16 Nodes

Add/Drop Multiplexing

(Tributary Add/Drop) -Only DS3s Changing Routes Or

Terminating Use DACS III


48 W

48 P

DACS

III

DCS

III

ADM

ADM ADM ADM

ADM ADM

48 W

48 P

All DS3s All DS3s

48 W

48 P

ET: End Terminal

ADM: Add/Drop Multiplexer

ET

ET ET

ET

ET ET

ET ET


24/58

Key SONET Configurations

Linear Office Sequences

Key SONET Configurations

Linear Office Sequences

ET IIIPoint

ToPoint

Linear

Add/Drop(Open Ring)

o o o IIIET ET IIIET ETIII ET IIIET ETETIII

N Offices

2 End Offices

N-2 Interior Offices

ET

IIIIII ETADM ADMET ADM ADM o o o


25/58

Key SONET ConfigurationsKey SONET Configurations

III III III

IIIIII

PointTo

Point

ClosedRing

w

P

Compatible With OLS

2 Nodes Per System

1x1 Protection Switching,

DACS III - Based Restoration

Compatible With OLS

2 To 16 Nodes - End Terminals At Ends,

ADMs Elsewhere

Add/Drop Multiplexing

(Tributary Add/Drop) 1x1 Protection Switching,

DACS III-Based Restoration At Ends& Add/Drop Points Only

Compatible With OLS

2 To 16 Nodes

Add/Drop Multiplexing(Tributary Add/Drop)


Ring Loopback Protection Switching

Must Be Of Uniform Size AroundEntire Loop

DACSIII

ET ET ET ET

MESH

RING

LinearAdd/Drop

(Open Ring)

DACSIII ADM

ET ETDACS

III

ADM ADM

ADM ADMADM

ET: End Terminal

ADM: Add/Drop Multiplexer

III

w

P

W

P

W P WP

w

P

w

P

w

P

W

P


26/58

Explanation of Wavelength

Division Multiplexing (WDM)

Explanation of Wavelength

Division Multiplexing (WDM)

Conventional System

Only 1 signal

Wavelength

WDM System

Multiple Signal

Wavelengths

Transmission capacity per fiber is multiplied by the number of Signal Wavelengths

Technological Difficulties- Signal multiplex/demultiplex

- Optical amplifier bandwidth limitation

- Inter-channel interaction due to optical fiber non-linearity

(four wave mixing and cross-phase modulation)


27/58

- 3 0

- 2 0

- 1 0

0

1 5 7 0 1 5 8 0 1 5 9 0 1 6 0 0

W a v e le n gt h ( n m )

Power

(dBm)

To get more information on a single fiber

Use more wavelengths (DWDM)


28/58


29/58

SONET Network ManagementSONET Network Management


30/58

Definition of a RingDefinition of a Ring

A Ring is a collection of nodes (NE1, NE2, .)

forming a closed loop.

Each node is connected to two adjacent nodes

via

a duplex communications facility.

A SONET Ring will provide:

Redundant Bandwidth

Redundant Network Equipment

or both


31/58

SONET Ring APS(Automatic Protection Switching)

SONET Ring APS(Automatic Protection Switching)

Uni-directional Vs. Bi-directional Rings

Two-Fiber Vs. Four Fiber Rings

Ring Switching Vs. Span Switching

Applications of: Bi-directional Line Switched Ring (BLSR) Uni-directional Path Switched Ring (UPSR)


32/58

Ring ClassificationRing Classification

A Unidirectional Line Switched Ring (ULSR)

A Bidirectional Line Switched Ring (BLSR)

A Unidirectional Path Switched Ring (UPSR) A Bidirectional Path Switched Ring (BPSR)

Any of the above type can be a two-fiber or a four fiber ring.

Therefore, for all practical applications, SONET/SDH standards

provide eight types of ring for network node interconnections


33/58

2 Fiber

Unidirectional Vs. Bidirectional Rings

2 Fiber

Unidirectional Vs. Bidirectional Rings

C

BA

D

Ap B : 1

BpA : 2p3p4

1W

2W

3W

4W

5P

6P

7P

8P

Unidirectional RingWorking Trafficflowsin Clockwise Direction

CCW DirectionisreservedforProtection

C

BA

D

Ap B : 1

BpA : 5

1W&P

2

3

4

5W&P

6

7

8

Bidirectional RingShortestdistanceavailablefortraffic

ofBandwidthisreservedforProtection


34/58

Two-Fiber Vs. Four-Fiber RingsTwo-Fiber Vs. Four-Fiber Rings

C

BA

D

A

BWorking 1

Protection 2

Working 2

Protection 1

A - Two-FiberRing/Span

C

BA

D

A

BWorking 1

Protection 1

Working 2

Protection 2

B - Four-FiberRing/Span


35/58

Ring Switching 2-Fiber RingRing Switching 2-Fiber Ring

C

BA

D

Failure

Route before PS (Protection Switching)

A: Ring Switching: Two-fiber ring

50%

50%

50% - original

+

50% - additional

50% - original

+

50% - additional


36/58

Ring Switching 4-Fiber RingRing Switching 4-Fiber Ring

B: Ring Switching: Four-fiber ring

C

BA

D

Route before PS


37/58

Span Switching - 4-fiber Rings

Only

Span Switching - 4-fiber Rings

Only

C

BA

D

Route before PS

B: Ring Switching: Four-fiber ring

A B

Route before PS

Route after PS


38/58

Bi-directional Line Switched Ring

No Failures


No Failures

CB

A

F

W

w

w

w

w

P

P

P

P

P

D

E

w

P

Original Circuit

A

B

C C

B

A

Bidirectional

Traffic

Unidirectional

Traffic


39/58


Span Switch


Span Switch

w

F

CB

w

w

W

W

P

P

P

P

P

D

E

W

P

X

A

Original Circuit

Protection Switch


40/58


Ring Switch


Ring Switch

w

E

CB

A

F

W

W

W

W

P

P

P

P

P

D

W

P

Original

Circuit

Ring Switch

X


41/58


Ring Switch - Node Failure


Ring Switch - Node Failure

F

CB

A

W

W

W

w

W

P

P

P

P

P

D

W

P

E

x Original CircuitRing Switch


42/58


No Failures


No Failures

CB

A

F

W

W

W

W

W

P

P

P

P

P

D

E

W

P

Original Circuits (Both Slot 2)


43/58


Need For Squelching


Need For Squelching

CB

A

F

W

W W

W

P

P

P

P

P

D

E

W

P

Original Circuits (Both Slot 2)X

Requires Sharing

of State Information

Significant Software

Complexity


44/58


Double Ring Failure (No Recovery)


Double Ring Failure (No Recovery)

Original Circuit

Ring Switch

CB

A

F

W

W

W

W

W

P

P

P

P

P

D

E

W

P

X

X


45/58

SONETRings will fail --The question is When?SONETRings will fail --

The question is When?

Initial estimates of DWDM hardware show that it is 8 times more

reliable than WDM equipment

POEs not included

Ring reliability is dependent upon ring mileage Ring sizes vary from 200 miles to 2800 miles

Ring Failures:

Given 100, 1000-mile perimeter rings:

Current optimistic estimation is 1 network ring failure every 5 yrs

PCIs not included

Most probable cause of a complete ring failure is an equipment failure

and a fiber cut

Physical diversity violations in some rings (single-pt-of-failure)


46/58

Ring Interworking

Interconnect Problem (No Recovery)

Ring Interworking

Interconnect Problem (No Recovery)

A

C

BD

Z

E

D

W

W

W

W

W

P

P

P

P

P

Office X

W

W

W

W

W

P

P

P

P

PRing

1

Ring

2

X

Original Circuit

Failure


47/58

Dual Ring Interworking

(Unidirectional A => Z Circuit)

No Failure



No Failure

A

C

B

Z

E

D

W

W

W

W

W

P

P

P

P

P

Office X

Office Y

W

W

W

W

W

P

P

P

P

P

SS

Ring

1

Ring

2

vv

v

v

v

v

v

Original Circuit

Secondary (Inactive)

vv


48/58



ADMFailure



ADMFailure

A

C

B

Z

E

D

W

W

W

W

W

P

P

P

P

P

Office X

Office Y

W

W

W

W

W

P

P

P

P

P

SS

Ring

1

Ring

2

v

v

v

v

XOriginal Circuit

Secondary Circuit

Ring Switch


49/58



Office OrDouble ADMFailure



Office OrDouble ADMFailure

Ev

A

C

B

Z

D

W

W

W

W

W

P

P

P

P

P

Office X

Office Y

W

W

W

W

W

P

P

P

P

PRing

1

Ring

2

SS

XXOriginal Circuit

Secondary Circuit

Ring Switch


50/58

Other Types Of SONET Self-Healing Rings

(2-Fiber Unidirectional Line-Switched Ring)



ADM

A

ADMADM

Z

ADM

Notes: Each Link Is Just 1 (1-Way) FiberTransmission Directions Routed Differently

Service

Service

Service

Service

Protection

Protection

Protection

Protection

A=>Z

Z=>A

Z=>A

A=>Z

A=>Z

Z=>A


51/58





ADM

A

ADMADM

Z

ADM

Service

Service

Service

Service

Protection

Protection

Protection

ProtectionZ=>A

A=>Z

Z=>A

A=>Z

Z=>A

A=>Z


52/58


(2-Fiber Bi-directional Line-Switched Ring)


(2-Fiber Bi-directional Line-Switched Ring)

ADM

A

ADMADM

Z

ADM

Note: Each Link Uses 1 (1-way) FiberCapacity On Each Fiber Divided Equally Between Service & Protection

(2 Logical Fibers)

Service/Protection

Service/Protection

Service/Protection

Service/Protection

Service/Protection

Service/Protection

Service/Protection

Service/Protection


53/58

BITSBITS


54/58


55/58

Clock Accuracy LevelsClock Accuracy Levels

S nc Stat s MessageS nc Stat s Message


56/58

Sync Status MessageSync Status Message

SS MessagesSS Messages


57/58

SS MessagesSS Messages


58/58

Documents

3 - Hotz-Globalcrossings Fiber & Long Lines