VOIP Voice Over Internet Protocol CDA 4527 Fall
- Slides: 7
VOIP (Voice Over Internet Protocol) CDA 4527 Fall 2006
Definition – also called IP Telephony, Internet telephony, Broadband Phone and Voice over Broadband – the routing of voice conversations over the Internet or through any other IP-based network Cisco IP Phone 7941 G
Big Picture • Modes of operation: – – PC to PC PC to phone Phone to PC Phone to Phone • Traffic go through Packet Switched Network instead of Public Switched Telephone Network (PSTN) From Wikipedia, the free encyclopedia
Why VOIP? • Much cheaper • Rich functionalities – Free phone numbers for use with Vo. IP are available in the USA, UK and other countries. – 3 -way calling, call forwarding, automatic redial, and caller ID… – Integrated with data, video communication • Mobility – Incoming phone calls can be automatically routed to your Vo. IP phone, regardless of where you are connected to the network
Challenges • Quality of Service (Qo. S) – Internet provides best of service – No guarantee for latency, jitter… • Need Internet connection – Home broadband is not reliable • Power issue – VOIP phone, Cable Modem/DSL, Computer
Challenges • Security – Most unencrypted – VOIP spam challenges • Integration into global telephone number system • Emergency call availability & functionality – Power, Internet connection – Call routing, location service
Qo. S • Deal with Jitter – Smoothed by playback buffer • Bandwidth – 64 kbps or less – Depends on codec and use of silence supression
