RAD Data Communications said Vmux gateways use voice codecs, silence suppression
and its TDMoIP multiplexing to minimise the bandwidth needed for voice transmission without affecting features such as voicemail, fax, modem and IVR.
The VMUX features the TDMoIP framing and aggregation technique that delivers superior bandwidth-efficiency, down to 4kb/s per channel and supports voice activity detection (VAD), silence suppression
and comfort noise generation (CNG), the company claims.
Packet engines handle all processing of Layers 1 through 5, including: protocol conversion, silence suppression
, comfort noise generation, jitter buffering, clock synchronization, dynamic packet reconstruction, and quality of service (QoS) policing.
Using VoIP technologies, such as the H.323 revision 2 protocol, G.711 A-Law/U-Law, silence suppression
and echo cancellation, the unit supports IP connections to any other H.323 revision 2-compatible IP telephony product.
Techniques that reduce bandwidth consumption can include zero-overhead packet labeling, voice compression, silence suppression
, voice channel multiplexing, embedded call signaling, broadcast management, packet authorization at source and reduced routing protocol traffic.
Voice quality must be addressed by use of the latest voice compression algorithms, such as G.729A and G.723.1, and can be further improved by supplemental techniques, such as silence suppression
and jitter buffering.
: Almost all of the DSPs used in today's VoFR implementations can detect and weed out silence patterns, reducing bandwidth requirements.