Mumbai University > Electronics Engineering > Sem 8 > Advanced Networking Technologies

Marks: 5M

Year: Dec 2011

• Frame Relay offer an option called VoFR that sends voice through FR network
• Voice is digitalized using PCM and then compressed
• The result is send is send as data frames over the network
• This features the inexpensive sending of voice over long distances
• However, the quality of voice is not as good as voice over a circuit switched network
• VoFR has an advantage over VoIP (Voice over Image Processing) is that overhead is considerably less and VoFR can guarantee a minimum through the CIR
• VoFR requires a virtual circuit between all communication end points (CPE routers)
• Vo coder is used for voice compression using G.729 Vo coder 64kbps is converted to 8 kbps compressed data
• Silent suspension or voice activity detection (VAD) are algorithms that are used to require packets to be transmitted only when there is voice energy thus reducing the network requirements by 50%
• This can occur because most people on a phone conversation are not speaking and listening at the same time.