Project P615
Evolution Towards and Optical Network Layer
Deliverable 2 Main Report
Comparison of Reference Configuration Models
Suggested readers:
· Public network operators studying potential upgrade possibilities for their PDH and/or SDH transmission networks
· Planners and OAM managers of (optical) transport networks
· System manufacturers involved in the development of optical network technology
· Research engineers working on optical transmission networks technologies
Draft 0.1 Ready for internal reviewi Draft 1.1 Ready for external review
Draft 1.2 Further improvements before external review
September 1998
For full publication
EURESCOM PARTICIPANTS in Project P615 are:
· British Telecom Plc.
· Hellenic Telecommunications Organisation S.A. (OTE)
· KPN Research (Royal PTT Netherlands)
· Hungarian Telecommunications Co. Matáv
· France Telecom
· Tele Danmark
· Portugal Telecom SA
· Swisscom
· Telefónica de España
This document contains material which is the copyright of certain EURESCOM PARTICIPANTS, and may not be reproduced or copied without permission
All PARTICIPANTS have agreed to full publication of this document
The commercial use of any information contained in this document may require a license from the proprietor of that information.
Neither the PARTICIPANTS nor EURESCOM warrant that the information contained in the report is capable of use, or that use of the information is free from risk, and accept no liability for loss or damage suffered by any person using this information.
This document has been approved by EURESCOM Board of Governors for distribution to all EURESCOM Shareholders.
Tables of Contents of Documnent Volumes Main Part
Comparison of Reference Configuration Models
Preface 1
Executive Summary 2
List of Authors 6
Table of Contents 7
Abbreviations 9
Glossary and Terms of Acronyms 9
Acronyms applied to identify study cases 9
1 Introduction 11
1.1 Motivations 11
1.2 EURESCOM P615 project 11
1.3 Structure of the document 12
2 Objectives 14
3 Analysis Methodology 15
3.1 Objectives 15
3.2 Basic Approach 15
3.3 Dimensioning 16
3.4 Cost Modelling and Calculation 17
3.5 Availability Modelling 17
3.6 Analysis of protection and restoration performances 19 3.7 Summary and the Main Steps of the Analysis 19
4 Network Study Cases 21
4.1 Objectives 21
4.2 List of architecture to be studied 21
4.3 Information to Specify a Network Study Case 21
4.4 Demands and Network Topologies 22
4.5. Protection Specifications for Study Cases 23
4.6 Ring Network Study Cases 23
4.7 Mesh Network Study Cases 24
4.8 Costs for modelling scenarios 24
4.9 Summary 25
5 Analysis of Optical Network Architecture 26
5.1. Dimensioning and cost analysis 26
5.2. Availability analysis 31
5.3. Analysis of OAM characteristics of optical architecture 35 5.3.1 Timing Equations of an (O)OMSSP Ring APS Protocol 36 5.3.2 Restoration in optical MWTN meshed architecture 39 5.4 Conclusions on the analysis of optical architectures 41 5.5 Some general considerations on the characteristics of pure optical network
architecture 42
6. Comparison of optical and reference SDH architecture 44 6.1 Comparison of dimensioning results and costs 44
6.2 Comparison of availability performance 49
6.3 Comparison of protection and restoration timing performances 50
7 Summaries and Conclusions 53
7.1 Summary on studied optical ring and mesh architecture 53
7. 2 Summary on analysis and comparison aspects 55
7.3 Summary and final conclusions 56
7. 4 Questions for further studies 56
References 58
Document History 59
Appendix - Tables of Contents of Annex Volumes 1
Annex A
Methodology of the analysis work
1. Introduction 3
1.1. Objectives, purpose of the document 3
1.2. Motivation - The role of the network analysis in P615 project 3
2. Analysis of network architectures 5
2.1 Analysis on the pure architectural level 5
2.2 Analysis through networking applications 6
2.3 Combined method 7
3. Risks and foreseen problems 8
3.1 Too many architecture to be studied 8
3.2 Lack of input data 8
3.2.1. Reliability modeling 9
3.2.2. Cost modeling 10
4. Network analysis and dimensioning 12
4.2. Offered SW tools 12
4.3. Experiences from the from demonstrative applications, evaluation
of the offered SW tools 12
5. Steps of the analysis process 15
5.1. The main steps of the analysis process 15
5.1.1. Steps of the analysis on architectural level 15 5.1.2. Steps of the analysis of networking applications 15 5.2.3. How to specify realistic network scenarios 15 5.2.3.1. Components of a network example to be specified 17
5.2.3.2. Transmission demands 18
5.2.3.3. Network topology 19
5.2.3.4. Node functionalities 20
5.2.2.1.5. Engineering and planning rules 21
6. Summary and Conclusions 22
7 Appendix - Brief description of offered SW tools 23
7.1 REFORMA - a network dimensioning tool 23
7.1.1. Purpose 23
7.1.2. REFORMA general characteristics 23
7.1.3. Existing REFORMA equipment prototypes 23
7.1.3.1 Fiber Span Node 23
7.1.3.2 Synchronous Terminal Multiplexer 23
7.1.3.3 Add & Drop Multiplexer 24
7.1.3.4. Digital Cross-connect 4x4 25
7.1.3.5. Digital Crossconnect 4x1 25
7.1.3 Ideas in the use of REFORMA with optical scenarios 25 7.2 MODLINE - a general network simulation tool 27 7.3. COMNET and OPNET - general network performance analysis tools 28
7.3.1 COMNET III 28
7.3.2 OPNET 30
7.4. SDHREL - a network reliability analysis tool 33
7.4.1 Introduction 33
7.4.2. The reliability model 33
7.4.3 Summary 34
References 35
Annex B
Detailed Specification of Study Cases
Table of Contents 3
1 Introduction 4
2 Specification of ring network scenarios 5
2.1 Description of the ring network 5
2.1.1 Description of coloured section ring 5
2.1 2 Description of OMS-SPRing 6
2.2 Ring network traffic demands 10
2.2.1 "Nearest neighbour" traffic demand 10
2.2.2 Hubbed traffic 10
2.2.3 Uniform traffic demand 11
2.3 Ring network cases summary 11
3 Specification of mesh network scenarios: MWTN mesh 13
3.1 Description of the mesh network 13
3.2 Mesh topologies 13
3.3 Protection 14
3.4 Traffic demands 15
3.4.1 "Nearest neighbour" traffic demand 15
3.4.2 Hubbed traffic 15
3.4.3 Uniform traffic demand 15
3.4.4 Traffic demands for the national network scenario 15
3.5 Mesh network cases summary 16
4 Costs for modeling the scenarios 18
4.1 Philosophy of costing for the scenarios 18
4.2 Fibre costs 18
Point-to-point system costs 19
4.3 Amplifier costs 19
4.4 Switch costs 20
4.5 Optical cross-connect costs 20
4.6 Conclusion on costs and evolution 21
5 Conclusions 23
6 References 24
Annex C
Detailed Numerical Results from the evaluation of the performance of optical scenarios
Volume 1/4
INTRODUCTION 7
OBJECTIVE 7
DOCUMENT STRUCTURE OF ANNEX D 9
TABLES OF CONTENTS OF THE DIFFERENT VOLUMES OF ANNEX D 10 Volume 2: Dimensioning and costing of the architectures 10
Volume 3: Availability study 11
Volume 4: Protection and restoration aspects study 11
Volume 2/4
2. RING ARCHITECTURES STUDY 7
2.1 INTRODUCTION 7
2.2 RING ARCHITECTURE ASSUMPTIONS 8
2.2.1 General assumptions 8
2.2.2 Dimensioning assumptions 11
2.3 DIMENSIONING METHODOLOGY 12
2.4 DIMENSIONING AND COST RESULTS 13
2.4.1 Five nodes. Nearest neighbour. Normal 13
2.4.2 Five nodes. Nearest neighbour. High 14
2.4.3 Five nodes. Hubbed. Normal 15
2.4.4 Five nodes. Hubbed. High 16
2.4.5 Five nodes. Uniform. Normal 17
2.4.6 Five nodes. Uniform. High 18
2.4.7 Eight nodes. Nearest neighbour. Normal 19
2.4.8 Eight nodes. Nearest neighbour. High 20
2.4.9 Eight nodes. Hubbed. Normal 21
2.4.10 Eight nodes. Hubbed. High 22
2.4.11 Eight nodes. Uniform. Normal 23
2.4.12 Eight nodes. Uniform. High 24
2.5 ELECTRICAL AND OPTICAL EQUIPMENT COST BREAKDOWN 25
2.6 ARCHITECTURE COMPARISONS 29
2.7 COMPARISONS WITH THE REFERENCE ARCHITECTURE 30 2.7.1 Architectures Cost Comparison: equipment cost and fibre length savings. 30 2.7.2 Architecture Cost Comparison: overall cost savings. 33
2.8 ARCHITECTURES SCALABILITY STUDY 33
2.8.1 Nearest Neighbour traffic pattern 34
2.8.2 Uniform traffic pattern 34
3. MESHED ARCHITECTURES STUDY 38
3.1 INTRODUCTION 38
3.2 DESCRIPTION OF THE NETWORK 38
3.2.1 SDH Network Architecture 39
3.2.2 MWTN Network Architecture 39
3.3 DIMENSIONING METHODOLOGY 41
3.3.1 Network protection 41
3.3.2 SDH case 42
3.3.3 MWTN case 42
3.4 DIMENSIONING AND COST RESULTS 43
3.4.1 Five nodes. Nearest neighbour. Normal 45
3.4.2 Five nodes. Nearest neighbour. High 46
3.4.3 Five nodes. Hubbed. Normal 47
3.4.4 Five nodes. Hubbed. High 48
3.4.5 Five n odes. Uniform. Normal 49
3.4.6 Five nodes. Uniform. High 50
3.4.7 Eight nodes. Nearest neighbour. Normal 51
3.4.8 Eight nodes. Nearest neighbour. High 52
3.4.9 Eight nodes. Hubbed. Normal 53
3.4.10 Eight nodes. Hubbed. High 54
3.4.11 Eight nodes. Uniform. Normal 55
3.4.12 Eight nodes. Uniform. High 56
3.4.13 Eight nodes. National. Normal 57
3.4.14 Eight nodes. National. High 58
3.5 CONCLUSIONS 59
3.5.1 Cost savings in electrical equipment and infrastructure for SDH and
MWTN architectures 59
3.5.2 Total cost of SDH and MWTN architectures 60 3.5.3 Relative cost of electrical equipment, optical equipment and
infrastructure to total cost 61
Volume 3/4
AVAILABILITY STUDY 7
INTRODUCTION 7
BACKGROUNDS 7
Reliability, availability 7
Architectures 7
Demand Patterns in general 7
Demands of the architecture with six and seven nodes 9
Span lengths 9
METHODS FOR AVAILABILITY ANALYSIS 9
Availability characteristics 9
Typical Demand analysis 10
Performance Index calculation 11
Comparison of the two methods 12
AVAILABILITY ANALYSIS OF P615 ARCHITECTURE 13
Introduction 13
Availability model of the ring architectures 14
Availability model of the Mesh Architecture 16
Availability analysis of the architecture with a single STM1 demand 21 Availability Analysis of Ring and Mesh Architecture with different demand
patterns 26
Network scalability results for rings and meshes 42 Breakdown of the DTR for STM1 demand analysis 52 Sensitivity study on the availability of OMSSP ring 61
A SEPARATE STUDY ON COLOURED SECTION RING PROTECTION 72
GENERAL COMMENTS AND CONCLUSIONS 75
Volume 4/4
PROTECTION AND RESTORATION ASPECTS STUDY 7
STUDY OF THE APS PROTOCOL FOR THE OMS-SP RING
ARCHITECTURE 7
Introduction 7
Network Objectives with APS Protocol 8
Timing Equations of an (O)MS-SPRing APS Protocol 9
Bidirectional signal fail (ring) 11
Node failure 12
Unidirectional signal fail (ring) 13
Unidirectional signal degrade (ring) 14
Analysis and Comparison 16
Summary 18
RESTORATION ASPECTS SIMULATION 18
Distributed Restoration Algorithm: “Sender-Chooser” 19
Architectures and Scenarios Studied 20
Assumptions 20
Results 22
Network Architecture: SDH Meshed 23
SDH: 5 nodes 24
SDH: 8 nodes 32
Network Architecture: MWTN 46
MWTN: Nodes with wavelength conversion 47
MWTN : Nodes without wavelength conversion 52
Double Failure cases 62
Discussion 66
Annex D
Comparison of optical and SDH architectures
TABLE OF CONTETNTS 3
INTRODUCTION 5
1 COMPARISON OF OPTICAL ARCHITECTURES ON VARIOUS
TOPICS 6
1.1 RING ARCHITECTURES 6
1.1.1 Protection 6
1.1.2 Availability 8
1.1.3 Dimensioning 10
1.1.4 Investment cost 12
1.1.5 Summary on rings 13
1.2 MESH ARCHITECTURES 15
1.2.1 Restoration 15
1.2.2 Availability 16
1.2.3 Investment cost 18
1.2.4 Summary on mesh 20
1.3 SUMMARY ON RING AND MESH ARCHITECTURES 20
2 CONCLUSIONS PER ARCHITECTURE 22
2.1 RING ARCHITECTURES 22
2.1.1 SDH ring 22
2.1.2 Coloured Section Ring 22
2.1.3 OMS SPRing 22
2.2 MESH ARCHITECTURES 23
2.2.1 SDH mesh 23
2.2.2 MWTN mesh 23
3 CONCLUSIONS 24
4 REFERENCES 25
Annex E
Protection in Colored Section Ring
Table of Contents 2
Introduction and Motivation 3
1. Colored Section Ring - a brief overview of the architecture 4
1.1 Node architecture 4
1.2 Routing 4
1.3 Extra feature - logical ring 5
1.4 Protection 6
2. Extra protection against node failure 8
2.1 MSSP ring over Colored Section ring 8
2.2. 1+1 path protection in Colored Section ring 8
2.3. Node reordering 10
2.4 Evaluation and comparison of different protection solutions 11
3. Summary and conclusions 14
4. References 15
Annex F
Availability Analysis and Potential Improvements of Optical Multiplex Section Shared Protected Ring
Table of Contents 2
1 Introduction 3
2 Ring architectures under study 4
2.1 Multiplex Section Shared Protected SDH Ring 4
2.2 Colored Section ring architecture 4
2.3 OMSSP architecture 5
3. Availability modelling 7
3.1. General approach to the availability modelling 7
3.2. Applied analysis tools and method 7
3.3. Reliability model of the selected architectures 8 4. Availability analysis of selected ring architectures 10 5. The backgrounds of the availability results of OMSSP ring 12
5.1. Breakdown analysis 12
5.2. Sensitivity analysis 13
6. Possible improvement of OMSSP ring 16
7. Improved availability with additional equipment level protection - results
and analysis of OMSSP ring 18
8. Conclusions 20
9. References 21
12 Annex: Detailed results 22
