VoIP Codec

A codec (compression/ decompression) is basically used to convert analog signals into digital bit stream or digital packets of data, which potentially means that the audio signals which are fed in as input data during a VoIP call gets coded into digital data packets that are sent across the high speed internet to the other end, where again the digital packets are decoded into analogue data and delivered to the second person.

Potentially VoIP technology functions on this very technique and hence a codec should rightly be termed as the work force of VoIP, for VoIP would fail if the analogue data did not convert into digital barring any uniqueness from how a regular PSTN phone functions. Codec’s for VoIP, used for transmission of data across IP networks are popularly known as voice encoders or vocoders.

With the popularity of VoIP, owing to its characteristics of adapting to the common infrastructure and delivering multiple services insistence of a quality codec to be installed in a network to convert signals from analogue to digital has risen.

Where bandwidth may not be a concern, network operators may want to differentiate service quality by offering wideband codec’s for better-than-PSTN voice quality

Specific coders for specific applications has increased the number of codec’s in the network including.726, G.729a/b/e/g, G.723.1, G.722, GSM-HR, EVRC, iLBC, Speex, GSM-FR and many more. The popular TDM standard G.711 for fixed access solutions poses issues for it being bandwidth intensive but network operators may offer wideband codec’s for VOIP voice quality to be better than PSTN voice quality to differentiate service quality of the two technologies.

Codec’s basically save network bandwidth with the ability to compress data in digital formats , optimization of bandwidth is supported to the extent that certain codec’s support silence suppression which means , when during a call there is silence it is not supported and encoded , proving better utilization of bandwidth

VoIP definitely is the technology of the future, providing greater access around the globe, with a bundle of hi end value added services and a minimum price to pay! However its impossible for VoIP to function without codec’s and now special codec’s are being designed for specific functions like separate VoIP codec’s , separate fax codec’s to facilitate faxing over the internet etc. A time is soon to come, when the face of VoIP would get transformed into something much sophisticated with the development of hi-end codec’s.