About the Book
The complete guide to deploying and operating SBC solutions, Including Cisco Unified Border Element (CUBE)
Enterprise and service provider networks are increasingly adopting SIP as the guiding protocol for session management, and require leveraging Session Border Controller (SBC) technology to enable this transition. Thousands of organizations have made the Cisco Unified Border Element (CUBE) their SBC technology of choice.
Understanding Session Border Controllers gives network professionals and consultants a comprehensive guide to SBC theory, design, deployment, operation, security, troubleshooting, and more. Using CUBE-based examples, the authors offer insights that will be valuable to technical professionals using any SBC solution.
The authors thoroughly cover native call control protocols, SBC behavior, and SBC’s benefits for topology abstraction, demarcation and security, media, and protocol interworking. They also present practical techniques and configurations for achieving interoperability with a wide variety of collaboration products and solutions.
Evaluate key benefits of SBC solutions for security, management, and interoperability
Master core concepts of SIP, H.323, DTMF, signaling interoperability, call routing, fax/modem over IP, security, media handling, and media/signal forking in the SBC context
Compare SBC deployment scenarios, and optimize deployment for your environment
Size and scale an SBC platform for your environment, prevent oversubscription of finite resources, and control cost through careful licensing
Use SBCs as a back-to-back user agent (B2BUA) to interoperate between asymmetric VoIP networks
Establish SIP trunking for PSTN access via SBCs
Interoperate with call servers, proxies, fax servers, ITSPs, redirect servers, call recording servers, contact centers, and other devices
Secure real-time communications over IP
Mitigate security threats associated with complex SIP deployments
Efficiently monitor and manage an SBC environment
Table of Contents:
Foreword xxx
Introduction xxxiii
Part I Introduction
Chapter 1 Laying the Groundwork 1
Overview of SIP 3
Overview of H.323 18
Introduction to SIP Trunking 20
Introduction to SDP 26
Overview of B2BUAs 42
Session Border Controllers 44
Cisco Unified Border Element 53
Summary 54
References 54
Chapter 2 SBC Deployment Models 55
Purposeful Deployments 56
CUBE Deployment Options 61
Multi-VRF Support on CUBE 68
SBC High Availability 72
Summary 108
References 109
Part II Architecture, Capabilities and Design
Chapter 3 Call Routing 111
Dialing and Routing a SIP Call 112
Call Routing Types 128
Next-Hop Determination 132
End-to-End Call Trace 141
CUBE Call Routing Mechanisms 149
Summary 221
References 222
Chapter 4 Signaling and Interworking 225
SIP—SIP Interworking 226
SIP Header Interworking 281
SIP Normalization 283
Transport and Protocol Interworking 299
Supplementary Services 312
SIP—H.323 Interworking 319
Summary 323
References 323
Chapter 5 Media Processing 327
Real-Time Transport Protocol 328
Real-Time Transport Control Protocol 334
SBC Handling of RTP and RTCP 341
Symmetric and Asymmetric RTP/RTCP 354
DSP-Based RTP Handling on SBCs 356
Media Anti-Tromboning 374
Alternative Network Address Types 378
Solving NAT Traversal Challenges 380
Troubleshooting RTP 404
Summary 413
References 413
Chapter 6 Secure Signaling and Media 415
Understanding Secure Technologies 415
Establishing Secure Sessions 449
SBC Signaling and Media Security 474
Alternative Security Methods 504
Summary 504
References 505
Chapter 7 DTMF Interworking 509
Introduction to DTMF Relay 510
Variants of DTMF Relay 512
DTMF Relay on SBCs 530
Configuring and Troubleshooting DTMF Relay 546
Summary 568
References 568
Chapter 8 Scalability Considerations 571
Platform Sizing 572
Licensing 598
Overload Prevention Techniques 610
Summary 625
References 626
Part III Integrations and Interoperability
Chapter 9 SIP Trunking for PSTN Access Through SBCs 627
Best Practices for ITSP Access with SBCs 628
SIP Trunk Registration 635
Authentication 642
Registration with SBCs 648
Troubleshooting 671
Summary 677
References 677
Chapter 10 Fax over IP (FoIP) on SBCs 679
Introduction to Fax 680
Analyzing a Basic Fax Call 683
Fax over IP (FoIP) 699
SBC Handling of FoIP 721
FoIP on CUBE 723
Summary 750
References 750
Chapter 11 Network-Based Call Recording 751
The Business Need for Call Recording 752
IETF SIP Recording Architecture (SIPREC) 753
SIPREC Configuration 763
SIPREC Troubleshooting 775
Cisco UC Gateway Services Architecture 789
The XCC and XMF Data Model 792
API-Based Recording 797
API-Based Recording Configuration 811
API-Based Recording Troubleshooting 823
Summary 836
References 836
Chapter 12 Contact Center Integration 839
Cisco UCCE Architecture 840
Inbound Calls to Agents 847
Call Transfers 885
Courtesy Callback 902
Call Progress Analysis (CPA) 914
Troubleshooting Scenarios 931
Summary 953
References 953
Part IV Security and Operations
Chapter 13 Security Threat Mitigation 955
An Overview of Security Threats to Collaboration Solutions 956
Types of Security Threats 959
Other SBC Security Features 998
Designing Collaboration Networks for Security 1009
Summary 1018
References 1018
Chapter 14 Monitoring and Management 1021
Monitoring 1021
Management 1050
Summary 1069
References 1070
Appendix A Q.850 Release Cause Values 1073
9781587144769, TOC, 11/7/2018
About the Author :
Kaustubh Inamdar, CCIE Voice No. 42277, is an escalation point for the Multiservice teams of the Cisco Unified Communications Technical Assistance Center (TAC) in India. He has worked on numerous complex VoIP issues for Cisco partners and key customers. He is a subject matter expert in the area of real-time communications and has deep knowledge of the associated standards and protocols. He is also the co-inventor of five patents (pending) in diverse areas such as collaboration, security, machine learning, and cloud technologies.
Steve Holl, CCIE Collaboration No. 22739, manages a global engineering team that supports the Cisco Collaboration as a Service (CaaS) offering for Cisco’s largest customers. Joining Cisco in 2005, he previously served as a team lead for voice solutions in the Global Technical Assistance Center (TAC). Steve graduated from the Rochester Institute of Technology with a bachelor of science in Applied Networking and System Administration, and he later completed a master’s of engineering in Engineering Management at the University of Colorado Boulder. In addition to holding a CCIE since 2008, Steve is also an ITIL Expert, PMP, and Six Sigma Black Belt. In his spare time, he enjoys cooking with his wife, Jenn, playing loud guitar solos, and undertaking outdoor adventures.
Gonzalo Salgueiro, CCIE No. 4541, is a Principal Engineer at Cisco, working on several emerging technologies and the services opportunities they offer. Gonzalo has spent more than 20 years at Cisco, establishing himself as a subject matter expert, an innovator, and an industry thought leader in various technologies, including Collaboration, ML/AI, Cloud, and IoT.
Gonzalo is an established member of numerous industry organizations and is a regular presenter and distinguished speaker at a variety of technical industry conferences and Cisco events around the world. He currently holds various industry leadership roles, including serving as a member of the Board of Directors of the SIP Forum, co-chair of the INSIPID and SIPBRANDY IETF working groups, a member of the IoT Directorate in the IETF, and co-chair of the WebRTC Task Group, IPv6 Task Group, and FoIP Task Group in the SIP Forum. He is an active contributor to various industry organizations and standardization activities.
Gonzalo previously co-authored the Cisco Press books IoT Fundamentals: Networking Technologies, Protocols, and Use Cases for the Internet of Things as well as Fax, Modem, and Text for IP Telephony. He has also co-authored 25 IETF RFCs, 4 IEEE papers, 4 ITU contributions, and numerous industry and academic research papers on a variety of different technical topics. He is also co-inventor of 100+ patents (issued and pending) and has contributed to various interop and open source development efforts. Gonzalo received a master’s degree in Physics from the University of Miami.
Kyzer Davis, CCIE Collaboration No. 54735, is an escalation point for the worldwide Multiservice teams of the Cisco Technical Assistance Center (TAC). He is the focal point for supporting, troubleshooting, and resolving complex solution-level problems involving Voice, Video, and Cloud portions of the Cisco Unified Collaboration product portfolio.
In addition to his work on this book, Kyzer has also authored numerous technical white papers on Cisco Collaboration configuration, architecture, and protocol design. In addition, he works with Learning@Cisco on strategy and content development for numerous Cisco certifications. Kyzer is a technology enthusiast and mentor who is always working on automation initiatives and dabbling with new and evolving technology in the lab. He also enjoys a mean barbecue.
Chidambaram (Arun) Arunachalam, CCIE No. 14809, is a Cisco Principal Engineer, responsible for resolving complex problems in large-scale collaboration networks. He works closely with engineering teams to drive solution-level serviceability requirements for end-to-end call signaling analysis in contact center environments and with industry experts for defining end-to-end SIP message logging capabilities (logme). He co-leads the Collaboration focus area within the TAC Technology office and is currently working on innovations such as Faster Cisco Support Experience (direct connection to engineer) and TAC Virtual Spaces (Webex Teams as a real-time communication channel for support engagements). He is a contributor to Wireshark and guides NCSU graduate students in developing Wireshark dissectors. His areas of interest include ease of doing business, talent development, and innovation.
