Can We Talk? Presented by Todd McIntire

1. Can We Talk?Presented byTodd McIntire

2. Can We Talk? • IP Telephony (VoIP) • Voice/Data Integration • PC/Telephony Convergence

3. IP Telephony Basics • Data networks use TCP/IP • Common protocol for disparate data networks • Time-share approach to sharing data between asynchronous devices • Packets travel when the network is available • Networks have variability and latency • Effective for email, file transfer, web browsing • Not effective for real time voice, video

4. IP Telephony Basics • Public Switched Telephone Networks • Dedicated circuit for each conversation • Analog voice signals are digitally encoded to cross public network then decoded back to analog at receiver • Digital packets must arrive at decoder in sequence and in regular increments of time • Latency and variability must be nearly zero for voice message to be intelligible

5. Voice vs. Data Networks • Voice • Sound bytes and silence bytes created, accepted, multiplexed, switched, transported and delivered at the frequent, regular and precise pace of every 125ms. • Data • packets created whenever there's some data around and move through the network whenever it's available.

6. Convergence—Voice over IP • Voice over IP (VoIP) • Must keep latency, variability and loss to a minimum • Use compression to reduce vulnerability to latency, variability and loss • Real-time Transport Protocol • Intelligent continuity algorithms at receiving decoder • Fill voids by stretching and blending voice packets

7. Advantages of VoIP • Cost—VoIP cost half of PSTN; fewer lines • Simplicity—Carry voice and data over same network • Integration—Single workstation for PC and telephony • Unified Services—Single mailbox for voice, fax and email