Voice-enabling the data network : H.323, MGCP, SIP, QoS, SLAs, and Security

Voice over IP (VoIP) is a fast-growing technology within telcos and ISPs. VoIP is significantly reducing the cost of transmitting telephone calls and enabling small companies to enter the +$50 billion marketplace. Many telcos and ISPs are entering this market while VoIP is still in its infancy. As a result, there is an urgent need for telco and ISP engineers to learn this new technology. This book will assist telco engineers to transition to IP networking with a focus on VoIP networks. This book introduces the fundamentals of IP networking as it applies to transmitting voice calls using IP packets. Key telco-based technologies such as SS7 are reviewed. A unique approach is that the book outlines each component of VoIP technology while describing the application of the technology. This is accomplished by describing key steps in designing an operational VoIP network, thereby enabling the reader to understand how this technology is applied.

1. The Telephony Service Provider: An Overview. Motivation for IP and Voice Convergence. VoIP Services on the Rise. Wholesale VoIP Service. Retail VoIP Service. Successful VoIP Deployments. The VoIP Network Architecture: Gateways and Gatekeepers. Seven Steps in Designing and Implementing a VoIP Network. Summary. 2. VoIP Network Architectures: H.323, SIP, and MGCP. H.323 VoIP Network Architecture. H.323 VoIP Services. H.323 VoIP Architecture Components. Gateway. Gatekeeper. Gateway and Gatekeeper Signaling. RAS. H.225. H.245. RTP. Directory Gatekeeper. SS7 Interconnection (PGW 2200 and SLT). VoIP Application Servers. SIP Network Architecture. SIP Network Services. SIP Network Architecture Components. SIP User Agents. SIP Gateways. SIP Servers. SIP Signaling Messages. H.323 and SIP Network Interworking. Softswitch Network Architecture. Softswitch Network Services. Softswitch Architecture Components. Softswitch. Call Agent Signaling. Gateways. Aggregation and Edge Routers. Feature Servers. Summary. 3. Offering Wholesale VoIP Services. Migrating Toward a VoIP Infrastructure. Wholesale Peering Arrangements. Call Routing. SS7 Interconnection to the PSTN. VoIP Billing Systems. Summary. 4. Offering Bundled Voice and Data Services. Overview of Managed Voice and Data Services. Integrated Access Architectures. Managed Voice and Data Services Using AAL2. Fundamentals of AAL2. Summary. 5. QoS Considerations in VoIP Network Design. IP Network Characteristics. Delay. Jitter. Packet Loss. Using QoS to Support VoIP Services. Choosing the Right QoS Approach. Overprovisioning. IntServ. DiffServ. QoS Building Blocks. Using DiffServ for VoIP Services: The EF Behavior. Implementing the EF Behavior. Dial Peer and NBAR. CB-Marking. QPPB: QoS Policy Propagation Through BGP. Congestion Management Using LLQ for VoIP. Avoiding Congestion in VoIP Networks. CAC for VoIP Networks. Local CAC. Network CAC. RSVP CAC. MPLS Supporting Voice. MPLS TE. Fast Re-Route for Voice. Summary. 6. Implementing the PSTN Switch/VoIP Gateway Trunk. Overview of VoIP Gateway to PSTN Connectivity. Circuit Types. Signaling Types. Case Study: JIT VoIP Network. T1, E1, and DS3 Fundamentals. Using T1s to Interconnect to the PSTN. Using E1s to Interconnect to a PSTN. Using DS3s to Interconnect to the PSTN. T1 CAS Trunks. T1 CAS Trunk Template. Signal Type. Line Code Method. Framing Mode. Incoming and Outgoing Digit Format. PRI Trunks. Q.921. Q.931. PRI Trunk Template. ISDN Variant. NFAS. Digit Sending Method. Incoming and Outgoing Digit Format. SS7 to Interconnect to the PSTN. SS7 Trunk Template. Mode. ISUP Variant. Signaling Speed. Signaling Channel. Point Codes. Network Indicator. CIC Mapping. Troubleshooting Techniques. Ensure Line Is up and Correct Synchronization and Clocking. Ensure D Channel Is up and Correct PRI Signaling. Ensure No Alarms. Loopback Test. CAS Troubleshooting. Summary. 7. Gateway and Gatekeeper Design Requirements. Gateway and Gatekeeper Design. Traffic Engineering. Erlangs. Trunk Sizing. Zones. Dial Peers. Normalization Rules. Dial Plan Administration. Gatekeepers and Directory Gatekeeper Sizing. High-Availability VoIP Network. Gateway High Availability. Gatekeeper High Availability. DGK High Availability. Troubleshooting Gateways and Gatekeepers. Summary. 8. Security Considerations for VoIP Networks. H.323 RAS Authentication. Network Access Security. Device Security. Using IPSec for Additional Security. Summary. 9. Network Management: Maintaining an SLA. Overview of Management Layers. VoIP SLA Management Architecture. Database. Probes and Local Collection Engine. Archive and Reporting Database. Trouble Ticket Application. Collecting the VoIP Management Data. Identifying the Data to Calculate the VoIP SLA Indicators. VoIP Management Data Sources: SNMP MIBs and Traps. VoIP Management Data Sources: Syslog and ASCII Message Collection. VoIP Management Data Sources: Relational Database and Trigger Collection. VoIP Management Data Sources: SA Agent Collection. VoIP Management Data Sources: NetFlow. Filtering and Correlating the Collected Data. Presenting and Reporting the Data. Summary.