Optical Transport Networking
Total Page:16
File Type:pdf, Size:1020Kb
Expert’s Guide to Optical Transport Networks: The Utilities Edition Optical Transport Networking by Paul Littlewood Fady Masoud with Malcolm Loro 2 Optical Transport Networking Published by Ciena 7035 Ridge Rd. Hanover, MD 21076 Copyright © 2015 by Ciena Corporation. All Rights Reserved. No part of this publication may be reproduced, stored in a retrieval system or transmitted in any form or by any means, electronic, mechanical, photo- copying, recording, scanning or otherwise, without the prior written permis- sion of Ciena Corporation. For information regarding permission, write to: Ciena Experts Books 7035 Ridge Rd Hanover, MD 21076. Trademarks: Ciena, all Ciena logos, and other associated marks and logos are trademarks and/or registered trademarks of Ciena Corporation both within and outside the United States of America, and may not be used without written permission. LIMITATION OF LIABILITY/DISCLAIMER OF WARRANTY: THE PUBLISHER AND THE AUTHOR MAKE NO REPRESENTATIONS OR WARRANTIES WITH RESPECT TO THE ACCURACY OR COMPLETENESS OF THE CONTENTS OF THIS WORK AND SPECIFICALLY DISCLAIM ALL WARRANTIES, INCLUDING WITHOUT LIMITATION WARRANTIES OF FITNESS FOR A PARTICULAR PURPOSE. NO WARRANTY MAY BE CREATED OR EXTENDED BY SALES OR PROMOTIONAL MATERIALS. THE ADVICE AND STRATEGIES CONTAINED HEREIN MAY NOT BE SUITABLE FOR EVERY SITUATION. THIS WORK IS SOLD WITH THE UNDERSTANDING THAT THE PUBLISHER IS NOT ENGAGED IN RENDERING LEGAL, ACCOUNTING, OR OTHER PROFESSIONAL SERVICES. IF PROFESSIONAL ASSISTANCE IS REQUIRED, THE SERVICES OF A COMPETENT PROFESSIONAL PERSON SHOULD BE SOUGHT. NEITHER THE PUBLISHER NOR THE AUTHOR SHALL BE LIABLE FOR DAMAGES ARISING HEREFROM. THE FACT THAT AN ORGANIZATION OR WEBSITE IS REFERRED TO IN THIS WORK AS A CITATION AND/ OR A POTENTIAL SOURCE OF FURTHER INFORMATION DOES NOT MEAN THAT THE AUTHOR OR THE PUBLISHER ENDORSES THE INFORMATION THE ORGANIZATION OR WEBSITE MAY PROVIDE OR RECOMMENDATIONS IT MAY MAKE. FURTHER, READERS SHOULD BE AWARE THAT INTERNET WEBSITES LISTED IN THIS WORK MAY HAVE CHANGED OR DISAPPEARED BETWEEN WHEN THIS WORK WAS WRITTEN AND WHEN IT IS READ. Manufactured in the United States of America Publisher’s Acknowledgments We’re proud of this book; please send us your comments at [email protected] Some of the people who helped bring this book to market include the following: Editorial and Senior Project Editor: Erin Malone Source Material: Barbara DePompa Layout and Graphics: Kevin Brubaker, Clark Design, Axis41, Susan MacLeod Editor: Kim Lindros Contents Executive Summary ......................................................................................6 What’s Driving the Adoption of OTN? ........................................................6 Network Modernization ..............................................................................6 Challenges Driving Utility Sector Modernization .......................................7 Understanding OTN ......................................................................................8 Advantages for Utilities ................................................................................8 Embracing OTN .............................................................................................8 Introduction: OTN Fundamentals .............................................................12 Advantages of OTN ...................................................................................12 What’s Driving the Adoption of OTN? ......................................................12 Competitive Advantages of OTN .............................................................13 Introduction: OTN Fundamentals .............................................................13 What Makes OTN Essential? .....................................................................15 Key OTN Benefits .......................................................................................16 Key Drivers in the Transition to OTN .......................................................18 OTN as the Successor to SONET and SDH ............................................20 OTN Values .................................................................................................20 OTN Architecture .......................................................................................21 OTN Bit Rates .............................................................................................24 OTN Multiplexing Hierarchy .....................................................................25 Forward Error Correction (FEC) .................................................................25 OTN Network Fit ........................................................................................27 Transforming Network Economics with OTN ...........................................27 Control Plane Compatibility and Features ...............................................32 OTN Market Acceptance ...........................................................................36 Use Cases ....................................................................................................37 Use Case 1: Bandwidth Grooming ............................................................37 Use Case 2: Network Path Optimization ..................................................37 Use Case 3: Core Router Offload ..............................................................38 Real-world OTN Selection Case ................................................................38 Conclusion ...................................................................................................39 Why Ciena? .................................................................................................40 OTN Glossary of Acronyms .......................................................................42 5 Executive Summary The adoption of Optical Transport Network (OTN) technology continues to gain momentum in the utilities market. This is attributable to the significant leap forward in optical network technology that OTN represents and the waning fortunes of SONET/SDH networking. Though this Expert’s Guide is an in-depth look at the technical underpinnings and architecture of OTN networks, it’s important to remember that OTN technology can solve business challenges for Ciena’s customers by increasing the performance of their networks while saving money, lowering latency, increasing network manageability and paving the way for the network to embrace Cloud and Software-Defined Networking. These aspects are described in this guide. What’s Driving the Adoption of OTN? When SONET/SDH was originally architected in the early 1990s, data and voice networks were designed and built separately. But almost immediately, SONET/SDH was being used to combine data and voice traffic onto a single transport network, with data network elements adopting voice transport protocols and interfaces. Adaptations were developed to map data traffic over SONET/SDH frames so carriers could use SONET/SDH networks, but this proved increasingly inefficient, because voice and data payloads are constructed at significantly different rates. The industry learned that OTN must be designed to provide data transport in a format native to data networking. This meant fixed frame sizes instead of the fixed frame rates inherent in SONET/ SDH. This fundamental change helps IP-based traffic to map into OTN much more efficiently than SONET/SDH. This tight integration of Internet Protocol (IP) and OTN via Ethernet is much more appropriate to the modern mix of networking protocols and traffic. The 40 Gigabits per second (Gb/s) line rate cap of SONET/SDH is no longer a barrier to data rate increases. Network Modernization OTN represents both a technical leap forward in optical networking. OTN allows network operators to evolve to a mesh overlay combining SONET/SDH, Ethernet and OTN payloads, providing an effective means to build a modernized infrastructure but still carry legacy traffic. This 6 architectural flexibility preserves existing investments in legacy transport while providing SONET/SDH access to 100 Gb/s lines and beyond. Selective upgrading, or capping and growing, allows network operators to evolve their networks in stages to avoid a costly disruption to core services or ‘all-at-once’ upgrade challenges. Opportunities abound for overcoming bandwidth, latency, and management hurdles by implementing converged networks of OTN and SONET/SDH. However, the real advantage for Ciena’s customers is the adoption of OTN to seamlessly handle Ethernet and data center protocols through the network edges and cores, optimizing existing investments in routing interfaces, eliminating router hops, and minimizing network latency. OTN is the technology platform upon which Ciena delivers connection-oriented Ethernet traffic to ensure consistent, high-throughput, low-latency delivery at the most economical price point of any optical networking technology. Challenges Driving Utility Sector Modernization Facing rising pressure to reduce costs, ensure reliability and shore up aging infrastructure, utilities are being challenged to streamline operations, with minimal risks or unintended impacts on customers. Today, more than ever, networks play a central role in creating a more stable, safe and resilient platform for electricity transmission and distribution, however, most current utility networks don’t provide the necessary scale, resilience and flexibility to meet growing operational requirements. Compounding the problem, most legacy serial and TDM circuit