Voice over IP Implementation

Transcription

1 Voice over IP Implementation Ruchi Prasad Director, Global CDMA Product Marketing November, 2004

2 VoIP Objectives Packetizing Traditional Voice Native VoIP On The Device Cost Savings Application Integration Application Integration Will Drive VoIP Implementation

3 Transport Convergence Optimized, Packetized Voice Transport Call Servers P-MSC, CS 2K Media Gateway Internet PDSN WLAN IP HA PDG MPE HA PDG IP BBSN WLAN Reducing the total cost of ownership Transport and transcoding optimization Reduced footprint and power Reduced number of switching centers

4 Services Convergence Enhanced Access 1xEV-DO Rel A Efficient support of real-time Apps Optimized Standardized services framework Opportunity for service integration Internet PDSN WLAN IP HA PDG MPE HA PDG IP BBSN WLAN Delivering revenue generating services Mass Market Real-time Apps like VoIP and Multimedia Broadcast/Multicast Apps Interworking between different Access Technology and Wireline

5 End to End Standards Perspective Go & Gq interfaces MMD (Q1 05) Support for Service Based Bearer Control Delivers common SIP services framework IP HSS SS7 GW App Servers AAA RADIUS PDF CSCF IM Subsystem PS Domain Compact Metrocell ebsc/rnc TIA856-A (published) TIA1054 (Q4 04) Throughput & packing efficiency improvements ACK based retransmission Support multi-flow operation for QoS Packet based framing Provide support for QoS and multiple service instances Support for inter-rnc handoff TIA835-D (Q1 05) QoS support BGCF MGW PDSN MGCF Improved slotted mode operation Internet Intranet TIA878-A (Q4 04) QoS support (QoS_BLOB flow mapping) IETF (published) Defined QoS specifications outside managed network

6 VoIP Implementation Challenges VoIP Capacity? QoS Procedures to agree between Access and Core? IMS Client Radio Resource Allocation Application based Prioritization BTS Transport Network SIP Media HA SIP Messaging Call Set up delay impact? CSCF HO Mobility Mgt Impact on Real Time App? IMS Client BTS Traffic Marking? External Networks: Traffic Priority Transcoding and Voice quality Controlling End to End Delay, Voice Quality, & Capacity To Provide A Consistent User Experience Wireless

7 Other VoIP Implementation Challenges Client / Devices Clients and Apps for Wireless and Wireline Devices (Video, PTT, VOIP) Dual mode devices to overcome coverage limitations 1X Interworking requirements MSC/IS-41 feature reuse 1X interworking for voice / data, requirements System Integration and Inter-op 3rd Party apps, clients, open interfaces (Interoperability and Performance Management is critical Security Management Firewall Traversals, Denial of Service attacks, Virus Protection, VPN Management Regulatory Issues CALEA, E911, inter/intra-lata, etc

8 VoIP Capacity / Quality Tradeoff System Capacity 1xEV-DO For CSD QOS Can we match 1X capacity? Best Effort Service Quality eg. HTML & Video Streaming 1X How far are you willing to back up on the quality curve for your voice? Circuit Switched Service Quality eg. VoIP QOS Delay & Jitter

9 VoIP End-End Delay & Optimization Chosen by source terminal or ingress GW Dependent on QoS provided by traversed networks (each network component has its specific contribution) Chosen by the destination terminal or egress GW Packetization delay Total minimal delay Total queuing delay Dejittering delay Echo control Dejittering delay Voice quality Packet size M2E delay Codec Capacity Header compression Balancing Voice Quality & capacity Network parameters Minimal delay Delay Jitter Packet loss Access parameters Dominated by FL, RL scheduling, physical layer characteristics and blocking model

10 VoIP Quality In An End-to to-end Network Voice quality is influenced by the various nodes involved in an end to end call Handheld AT Quality codecs AT Modem Improve Echo Return Loss Air link loading - delay SIP compression BTS RNC HA A A PC Land Phones LAN Phones Handoff Performance Jitter Buffer Optimization - Reduce nodal delay Prioritize traffic (Diffserv, MPLS ) IMS MGW Wireless Network ISP Mdm BB Mdm - or - IP Phone IMS MGW (Circuit MSC) MSC Remove latency Implement TrFO Packetized Circuit Core MG BSC BTS

11 Implementing Mobile VoIP PDSN 1 PDSN 2 RNC A RNC C Inter-RNC Inter-RNC soft Handoff Pre-standard RNC B RNC D 1X Intra-RNC 1xEV-DO Rel A Data Source Channel Defined Quantification upon implementation in field 1xEV-DO-Rel A 1xEV-DO-Rel A Inter-Technology Handoff 1xEV-DO to 1X (CS) Not defined Lose voice session when you move out of DO Coverage Inter-PDSN IS-835B Inter-PDSN Fast Handoff Defined

12 What is Quality of Experience? QoE is the end user s perception of service performance QoE reflects the user s experience efficiency of task completion: what does the user want to do? ease of use: is it easy to see how it works and what is happening? transparency of technology: does the technology facilitate the task or does it get in the way? QoE is quantified using behavioral science methods i.e., subjective testing Performance limits based on QoE are used to ensure that the service delivers acceptable performance North American users expectations Expect dial tone immediately Expect the call to go through right away Expect to keep the line as long as they want it Expect to be able to hear and converse on the call almost as easily as they do in person Wireless Users are willing to accept a slightly lower voice quality as a tradeoff for the benefit of unlimited mobility Wireless Users are accustomed to having different voice quality calls dependant on destination. (i.e. Land terminated = good, Mobile Terminated= lower quality due to end user location or environment) Voice QoE = f( delay, distortion, loss plan, echo control)

13 Nortel Networks Delivers End to End QoE For VoIP Network Metrics RF Coverage Blocking rate Drop rate Delay Throughput Jitter BLER QoE Indicators No service available Service rejected Call setup time Response time Stream blocking/freezing Visual noise Audio quality Roaming HLR Partners MSC GRX SIG IWF BG BG Wireless Gateway WG AN ATM or IP Packet Core Wireless Gateway WG AN PP8600 PP8600 RNC RNC BSC GGSN GGSN PP8600 PP8600 PP8600 PP8600 Intranets BGP Firewall -4 Router Alteon LoadBalancing Network Management Center BGP BGP Router Router Data Center Internet Network End-User Perception Optimizing infrastructure and application/clients to deliver satisfactory QoE in a cost efficient manner