SONET & SDH DOCUMENTS

8/10/2019 SONET & SDH DOCUMENTS

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222 2003, Cisco Systems, Inc. All rights reserved.R4.0 Marquee Orientation

Why SDH/SONET?

SDH (Synchronous Digital Hierarchy) and SONET (SynchronousOptical NETwork)are standards for interfacing optical networks.

Simple multiplexing processes

Easy access to various signals in a multiplexed high bit ratesignal

A flexible and efficient way of networking Network Distribution: Add/Drop capability

Network survivability: APS (Automatic Protection Switching)

Traffic Cross connection: capacity management, bandwidthmanagement and protection route diversity

Support advance Network Management System (OAM&P)Overhead bits for Fault, Configuration, Performance Monitoring,Security and Accounting management

Standardized interface can support multi vendor interworking,international connection and many different services; i.e. ATM,IP


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SONET/SDH Digital Hierarchy

Optical

Level

SONET

Electrical

Level

SDH

Equivalent

Line Rate

(Mbps)

Payload

Rate

(Mbps)

Overhead

Rate

(Mbps)

SONET

Capacity

SDH

Capacity

OC-1 STS-1 51.840 50.112 1.728 28 DS-1s or

1 DS-3

21 E1s

OC-3 STS-3 STM-1 155.520 150.336 5.184 84 DS-1s or

3 DS-3s

63 E1s or

1 E4

OC-12 STS-12 STM-4 622.080 601.344 20.736 336 DS-1s or

12 DS-3s

252 E1s or

4 E4s

OC-48 STS-48 STM-16 2488.320 2405.376 82.944 1,344 DS-1s or

192 DS-3s

1,008 E1s or

16 E4s

OC-192 STS-192 STM-64 9953.280 9621.504 331.776 5,376 DS-1s or

192 DS-3s

4,032 E1s or

64 E4s

Note:

Although an SDH STM-1 has the same bit rate as the SONET STS-3, the two signals contain different frame structures.

STM = Synchronous Transport Module (ITU-T)

STS = Synchronous Transfer Signal (ANSI)

OC = Optical Carrier (ANSI)


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SDH and SONET Bit Rate

SDH Bit Rate SONET

STM-1

STM-64 OC-192

OC-3

9.95Gb/s

155Mb/s

STM-4 OC-12622Mb/s

STM-16 OC-482.48Gb/s

STM-0 OC-1(STS-1)

51Mb/s


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What is different about SDH vs. SONET?

Together they are a set of global standards that interfaceequipment from different vendors. SDH is basically theinternational version of SONET, and SONET can be thought ofas the North American version of SDH.

There are some slight differences between SONET and SDH.

The main differences are in the basic SDH and SONET frameformats, but SDH and SONET are essentially identical beyondthe STS-3 signal level. The base signal for SONET is STS-1 andthe base signal for SDH is STM-1. STS-3c is equivalent to STM-1

and the lower tributaries can be mapped interchangeablybetween the two formats from that point on.


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What is different about SDH vs. SONET?(Cont)

In SDH, both electrical and optical signals are referred to as STMsignals.

In SONET, however, electrical signals are called STS and opticalsignals are referred to as OC.


7/23777 2003, Cisco Systems, Inc. All rights reserved.R4.0 Marquee Orientation

SONET

Defined by Bellcore and ANSI T1.X committees

Base rate (High Order) is 51.84Mbps (STS-1)

STS-1 Synchronous Payload Envelope (SPE) =50.112M used for carrying tributaries or a DS3 signal

Tributaries (Low Order) used for SONET are:

VT1.5 (SPE Trib) = 1.728M for carrying DS1 (1.544)

VT2 (SPE Trib) = 2.304M for carrying CEPT (E1, 2.048)

VT6 (SPE Trib) = 6.912M, Never formalized samerate as VT Group



SONET Hierarchy

x7

E1

DS1

x1

x3

x4

Tributaries of Base Signal

(Low Order Payloads)

xN

Broadband STS-N Payloads(High Order Payloads)

VT 1.5

VT Group

VT 2

VT 6VT6

SPE

VT2

SPE

VT1.5

SPE

STS-N

STS-1

SPE

STS-N

SPE

x1

DS3x1

Data



STS-1 Frame with VT Mapping

Section OH

Line OH

3 bytes

3

1

5

87 bytes

STS-1 SPE

STS-1 SPE Payload

DS3 Mapped or

7x VTG Mapped

J1

B3

C2

G1

F2H4

F3

K3

Z3

STS Pointer

VT

Group

VT

Group

VT

Group

VT

Group

VT

Group

VT

Group

VT

Group

V

T

1

5

Vx

ptr



Points to Remember in SONET

The base layer is the STS-1 SPESingle pointer to get to the STS-1 SPE (50MB level)

ALL tributary signals multiplex (via Pointer Processing)to the STS-1 SPE

Each STS-1 has its own path overheadTOH is called Section and Line Overhead

SS bits (in H1) is set to 00

Bellcore (Telcordia) Alarming and GR-820 Performance

MonitoringOther Nuances:

Path Trace is 64bytes, Orderwire is Mu-Law, Z bytesnot used, No J2, APS is different



SDH

Defined by ITU-T (previously CCITT) committees

Base rate (High Order) is 155.520 (STM-1)

Virtual Container 4 (VC-4) = 150.336M used for carryingtributaries or an E4 signal (or data)

Tributaries (Low Order) used for SDH are:

VC-11 = 1.728M for carrying DS1 (1.544) (rarely used inAU4)

VC-12 = 2.304M for carrying CEPT (E1)

Also a stuffing option for mapping VC11/1.5M to TU-12

VC-2 = 6.912M Just gaining acceptance (TU-2-Mc) for data

VC-3 = 50.112M (Same as STS-1 SPE) used for E3 AND DS3



SDH Hierarchy

STM-16 AU-4-16c C-4-16cVC-4-16c

E1: 2.048Mb/s

E4: 139.264Mb/s

STM-4

STM-1

AU-4-4c

AU-4

AU-3

VC-4-4c

VC-4

C-4-4c

C-4

C-3

C-2

C-12

C-11

VC-3

VC-2

VC-12

VC-11

TUG-3

TUG-2

DS1:1.544Mb/s

E3: 34.368Mb/sDS3: 44.736Mb/s

DS2:6.312 Mb/s

VC-3

TU-3

TU-11

TU-12

TU-2

x4

x3

x1

x7x7

x3x3

564.992Mb/s

2259.968Mb/s

VC-n

AU-n

AUG

STM-n Synchronous Transport Module

Administrative Unit Group: One or

more AU(s)

Administrative Unit: VC + pointers

Virtual Container: payload + path

overhead

STM-64 AU-4-64c VC-4-64c C-4-64c

AUG

x16

x4

x4x64

x16

x4

9039.872Mb/s

Containers of Base Signal

(Low Order Payloads)

High Order Payloads



STM-1 Frame with AU-4 Mapping

Regenerator

Section OH

Multiplex

Section

OH

9 bytes

3

1

5

261 bytes

VC-4 Payload:

C4 or TUG-3 mapped

J1

B3

C2

G1

F2

H4

F3

K3

N1

H1

H2

H3

H1

H2

H3

H1

H2

H3

C-3

Payload

J1

B3

C2

G1

F2

H4F3

K3

N15

bytes

Higher Order

Path OH

AU Pointer

TUG-3

TUG-2/VC12

Muxed

C-3

Payload

J1

B3

C2

G1

F2

H4F3

K3

N1

V

C

1

2

Vx

ptr

Low Order

Path OH


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2003, Cisco Systems, Inc. All rights reserved.R4.0 Marquee Orientation

SONET Vs. SDH

SONET UPSR = SDH SNCP (Sub-Network Connection

Protection)

WTR is up to 12 minutes in 1 minute increments

Hold-off timer for SDH 0-10S in 100mS increments

SONET BLSR = SDH MS-SPRing (Multiplex SectionShared

Protection Ring), SDH does not specify MS-SPRing @ STM-4(but we allow it)

SONET APS = SDH MSP (Multiplex Section Protection)

SONET Mesh/ Virtual Ring = SDH Same as/Extension of SNCP(and this has been around a while in SDH Networks)

SONET Path Trace = SDH Path Access Point Identifier (P-API, orAPI)

SONET Alarms: CR, MJ, MN = SDH Alarms PMA (PromptMaintenance Activity), DMA (Deferred Maintenance Activity): Wekept the CR/MJ/MN and added the -PMA/DMA as a suffix


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SONET Vs. SDH (cont)

SDH Collects Errored Block Seconds, Errored Second Ratios

SDH is beginning to use Tandem Connection MonitoringPath within a path

Adds additional Path Trace, BIP, FEBE and RDI to a high orlow-order path

SONET, STS-SPE (50.112M) is the base-rate payloadSDH, thebase is 155M and the VC-3 (STS equivalent) is a tributary tothe VC-4

Its not a central office, its an Exchange

Its not a Class 5/ Class 4, its a Local Switch and a TransitSwitch

Its not a DCS, its a DXC

SONET uses 3/3s and 3/1s, SDH uses 4/4s and 4/3/1s


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Terminology Summary

SDH SONET

STM-1 OC-3

STM-4 OC-12

STM-16 OC-48

STM-64 OC-192

STM-256 OC-768

Optical I/O Board

SDH SONET

Not applicable STS-1

VC4 STS-3c

VC4-4c STS-12c

VC4-8c STS-24c

VC4-16c STS-48c

VC4-64c STS-192c

Path Type


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Terminology Summary

SDH SONET

MSP APS/FFP

MS-SPRing BLSR

SNCP PPMN/UPSR

Protection Type Overhead Naming

SDH SONET

RS - RegeneratorSection

Section

MS - Multiplex

SectionLine

HP - High Order

PathPath


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Terminology Summary

SDH SONET

AU-LOP LOP-P

AU-AIS AIS-P

HP-UNEQ UNEQ-P

HP-TIM TIM-P

HP-SLM SLM-P

HP-RDI RDI-P/RFI-P

HP-DEG SD-P

HP-EXC SF-P

HP-REI REI-P

Alarms

SDH SONET

LOS LOS

LOF LOF

RS-TIM TIM-S

MS-AIS AIS-L

MS-RDI RDI-L/RFI-L

MS-DEG SD-L

MS-EXC SF-L

MS-REI REI-L


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Terminology Summary

PM Monitored Types

SDH SONETNot defined CV Code Violation

EB Errored Block Not defined

BBE Background Block Error Not defined

ES Errored second ES Errored second

Not defined SEFS - Severely Errored Framing Seconds

SES - Severely Errored Second SES - Severely Errored Second

Not defined FC- Failure Count

UAS - Unavailable Second UAS - Unavailable Second

BBER - Background Block Errored Ratio Not defined

ESR Errored second Ratio Not defined

SESR - Severely Errored Second Ratio Not defined


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Terminology Summary

SDH SONETNot defined CV-S

RS-EB Not defined

RS-BBE Not definedRS-ES ES-S

Not defined CV-LNE

Not defined CV-LFE

MS-EB-NE Not defined

MS-EB-FE Not definedMS-BBE-NE Not defined

MS-BBE-FE Not defined

MS-ES-NE ES-LNE

MS-ES-FE ES-LFE

PM Monitored Entities SDH SONET

Not defined FC-LNE

Not defined FC-LFE

MS-UAS-NE UAS-LNE

MS-UAS-FE UAS-LFENot defined CV-PNE

Not defined CV-PFE

HP-EB-NE Not defined

HP-EB-FE Not defined

HP-BBE-NE Not definedHP-BBE-FE Not defined

HP-ES-NE ES-PNE

HP-ES-FE ES-PFE

HP-SES-NE SES-PNE

HP-SES-FE SES-PFE


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Terminology Summary

PM Monitored Entities (Cont.)

SDH SONET

Not defined FC-PNE

Not defined FC-PFE

HP-UAS-NE UAS-PNE

HP-UAS-FE UAS-PFE

HP-BBER-NE Not defined

HP-BBER-FE Not defined

HP-ESR-NE Not definedHP-ESR-FE Not defined

HP-SESR-NE Not defined

HP-SESR-FE Not defined


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SONET & SDH DOCUMENTS

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