IP Telephony Interconnection Reference: Challenges, Models, and Engineering

 Content: Acronyms and Abbreviations   The Rise of IP-Based Voice and the Need for Global IP Telephony Reachability Introduction  New Challenges on VoIP Service Offerings  Why Global IP Telephony Reachability Is Needed  The VoIP Protocols Jungle    Overview    SIP    SDP    RTP/RTCP    SIP-I    SIP-T    BICC    IAX    DUNDi    TRIP    TGREP    ENUM  What Is This Book about?  IP TELEPHONY: OVERVIEW  Traffic Analysis VoIP versus PSTN /Mobile  This Chapter at a Glance  Fixed VoIP    Focus on France    Focus on Portugal    Focus on Latin America    Focus on South Korea    Focus on the United States Mobile VoIP Peer-to-Peer (P2P)  References   IMS: IP Multimedia Subsystem  What Is IMS?    Transport Layer    Control Layer    Service Layer  IMS Functional Elements    Call Session Control Function (CSCF)    Home Subscription Server (HSS)    PSTN Gateways    Application Servers (AS)    IMS Flow Examples  References  Further Reading   TISP AN Overview Overview   Brief History Concerning NGN Standardization    Basic Principles    TISPAN Functional Architecture    Brief Description of the Subsystems   Service Level    Transport Layer Protocols   SIP    Diameter    H.248 Interface between NGN and Legacy Networks    PSTN/ISDN Interconnection   IP-Based External Network Interconnection    Interoperator IP Backbone Network  References  Interconnection Practices in PSTN  Overview  Interconnection Services Access    Interconnection Points    Interconnection Circuits   Interconnection Services    Signaling  Traffic Interconnection Circuits    Interconnection through Circuits Provided by Other Operators  Traffic Registration  Interconnection Planning and Developing   Interconnection Establishment Previous Information  Services and New Services Security and Protection  Numbering  Technical Characteristics    Interconnection Circuits Transmission Characteristics   Signaling Interfaces between Exchanges   Signaling Network Structure   Synchronization between Networks    Quality of Service (QoS)    Operation, Management, and Maintenance  Capacity Resale  Prices  Transit  PSTN Interconnection: Economic Models    CPNP (Calling Party Network Pays)    BAK (Bill and Keep)    Optimize Interconnection Costs  References Further Reading  Roaming Practices in Mobile Networks  Overview Roaming  Types of Roaming  Roaming Agreements  Roaming Data IMS Roaming References  Interconnection Practices in GPRS Networks  Interconnection Practices in GPRS Networks  IMS Interconnection    Requirements for Voice Calls    SIP Profile    Advanced Services  References   IP TELEPHONY INTERCONNECTION: REQUIREMENTS AND BUSINESS MODEL  Terminology and Definitions VoIP Service Providers and Telephony Service Providers  VoIP Service Providers    Traditional Service Providers    VoIP Service Providers a la Internet  Definitions    Address of Record    Address of Contact    Back-to-Back User Agent (B2BUA)    Call    Initiator, Calling Party, Caller    Invitee, Invited User, Called Party, Callee    Registrar    End Point  IP Network Provider and Service Provider  IP Telephony Administrative Domain (ITAD)    Proxy Server (PS)    Location Server (LS)    Interconnection Node (IN)    Signaling Path Border Element (SBE)   Data Path Border Element  IP Telephony Administrative Domain and Autonomous Systems  Frontiers between ITADs and ASs  Adjacent Domains  Balanced/Unbalanced Traffic  Symmetric/Asymmetric Telephony Paths  Interconnection and Peering  Anonymization  Assumptions References  Business Actors and Relationships  Panorama of Main VoIP Service Providers    Incumbent Operators    "Virtual" VoIP Operators    Proprietary Third-Party VoIP Service Providers  Cooperation Agreements between Different Types of VoIP Service Providers  Business Actors Involved in VoIP Interconnection    Customer    End User    Service Provider   Network Provider  Business Relationships    SLA (Service Level Agreement)    CPA (Connectivity Provisioning Agreement)    NIA (Network Interconnection Agreement)    SIA (Service Interconnection Agreement)    Conclusion  References  IP Telephony Interconnection: Service Requirements  Introduction  Telephony Service Providers: Toward Global IP Telephony Services    No Assumption on the Intraprovide Service Engineering    Support of Various Interconnection Models   IP Version Agnostic    Global Coverage    Support of numbering Schemes Other Than E.164    Discovery of Remote Voip Service Providers and Their Capabilities    Service Interconnection Agreement Flexibility    Interoperability   Exchange of Homogenous IP Telephony Routing Data    Avoid Signaling Loop    Ability to Configure the Call Route Selection Process    Support of Multiple Interprovider Telephony Routes   Optimization of Signaling Paths and Media Paths    Resilience and Availability of the VoIP Service at the Service and Control Layers    Synchronize Service Layer and Control Layer   Ability to Detect IP Network Provider Spirals    Ability to Evaluate the QoS Treatment When Selecting a Given Inter-ITAD Path    Operation and Maintenance (O&M)    Charging and Billing    Interprovider Interconnection Agreements Assurance and Monitoring    Support of Import and Export Policies    Security   Protect against SPAM over Telephony (SPIT)    Support of Privacy and Confidentiality    No Assumption on the Negotiated Media Session    Load    Path-Coupled and Path-Decoupled Models    Planned Maintenance Operations  Customer Requirements   Global Reachability    Transparency of Interdomain Media Sessions    Quality of Service (QoS)    Cost    Reliability and Robustness    Ability to evaluate the QoS provided by the VoIP Service    Service Mobility and Roaming    Confidentiality and Privacy    Anonymization and Customization    Freedom of CODEC Usage    Free to Subscribe to a Service Offering    Service Not Bound to a Specific Interface    Environmental Impact   Support of Emergency Calls    Ability to Support Heterogeneous Calls    SLA Verification  References  Further Readings  Telephony Interconnection: Regulatory Constraints  European Commission Activities    Analysis    Constraints on Service Providers Following the Adoption of the Review Proposals  Current Activities in Europe and the United States   Ofcom    OPTA    BNetzA    AGCOM    ANACOM    RTR    FCC (Federal Communication Commission)  References  IP TELEPHONY INTERCONNECTION: STATE-OF-THE-ART AND INTERCONNECTION MODELS  Related Ongoing Activities Introduction  Current Number Portability Practices    The Need for Number Portability    Types of Number Portability    Service Provider Number Portability Schemes    All Call Query (ACQ)    Query on Release (QoR) Scheme    Call Dropback Scheme    Onward Routing (OR) Scheme    Comparisons of the Various Schemes    Database Queries and Call Routing    Potential Implications for VoIP  ENUM    Overview and Use Cases    ENUM Deployment Models    Source-Based ENUM Query/Answer Mechanism  ISN  i3 Forum    SIP Profile    Media    Dimensioning SPEERMINT IETF Working Group    Overview    The SPEERMINT Reference Architecture    Interconnection Relationships VIPR  Voice Peering Fabric  Cable Operators    PacketCable Overview   PacketCable Architecture    Interconnect Functional Component   ENUM Server Provisioning Protocol (ESPP)  References  Further Readings VoIP Interconnection Models  Introduction  Interconnection Models    Star Model    Centralized Model    Hybrid Model    Cascaded Model  Analysis of Interconnection Models  Reference  Interconnection Nodes: Usage of Session Border Controllers  Deployment Context  Technical Features    Topology Hiding    Media Traffic Shaping    Fixing Capability Mismatches   NAT Traversal    Access Control    Protocol Repair    Media Encryption  Focus on Interconnection Segment  Interconnection Scenarios    SBCs at the Border of Each ITAD    Shared Interconnection SBC    Telephony Exchange Point  References   Implementation Models for IP Telephony Interconnection at Large Introduction  DNS-Based Mode    Flooding Approach  Signaling    Media Layer Interactions  References   IP: TELEPHONY INTERCONNECTION ENGINEERING ISSUES AND SOLUTION SPACE  Service Engineering Issues  Content of Agreements    Content of Service Level Agreements (SLA)    Content of Service Interconnection Agreement (SIA)  Advertisement and Discovery  End-to-End Signaling Path Optimization  End-to-End Media Path Optimization  Dynamic and Flexible Interprovider IP Telephony Routing IP Network Provider Spiraling  Synchronization between the Service and Network Layer  Interprovider Congestion  Interprovider Load Balancing  Optimize Interconnection Costs  Optimize Interconnection Agreements  Bidirectionality Issue  Legal Intercept Issues Topology Hiding Correlating between Signaling and Media Streams  Shaping and Policing Frozen Interconnection Architecture  Interprovider Monitoring   General Overview   What Is Good Quality?   Probes    Signaling    Interprovider Monitoring Issues  Service Interconnection Assurance and Fulfilment  Security Issues  References   Solution Space  Overview  TRIP (Telephony Routing IP Protocol)    Why a Dynamic Protocol Is Needed    TRIP at a Glance    ITAD Numbers   Transport Considerations    TRIP Messages    TRIP Attributes  Extend TRIP to Advertise Diverse URI Schemes   Needs    Proposal  Advertise AS Path in the Telephony Signaling Protocol    INP Spiral Issues    Prevent INP Spiral  Optimize Inter-ITAD Quality of Service (QoS)    Service Need   Solution Proposal   QoS Route Capability    Modified TRIP Route Attribute    On the Utilization of QoS Information    Illustration Example  Interprovider Multiple Paths    Path Diversity    Enhance TRIP to Support Multiple Paths    Procedure    Example  Avoid Inter-ITAD Congestion Phenomenon    Avoid Congested Links and ITADs    TRIP-Based Procedure to Prevent Congestion  Summary  References   VoIP Interconnection Perspectives
 Abstract:             "Written to address the growth of IP telephony service offerings within the corporate and residential realm, this book discusses technical and regulatory issues related to IP Telephony Interconnection. It describes business and interconnection models and solutions, and provides an overview of emerging architectures such as IMS and TISPAN. The authors offer a detailed overview of the SPPEERMINT activity and proposed architecture, the current work undertaken in DRINKS, the use of ENUM for interconnection, and ENUM implementation status, among others. This text is a first of its kind to offer information on inter-provider communications and interconnect IP telephony clouds"