Tag Archives: codec bandwidth

Which Codec Should You Use for SIP Trunks

V1 VoIP thinks of voice quality on quite a different scale for VoIP users than with a standard cell phone call. While comparing the two might be simple, the better method when evaluating the quality of VoIP call quality is the codec. Assigned and a scale called the mean opinion score.

A codec, which stands for coder-decoder, converts an audio signal (your voice) into compressed digital form for transmission (VoIP) and then back into an uncompressed audio signal for replay. It’s the essence of VoIP. Codecs vary in the sound quality, the bandwidth required, the computational requirements, etc. Each service, program, phone, gateway, etc., typically supports several different codecs, and when talking to each other, negotiate which codec they will use.

Some codecs are royalty free, while others require licensing, often included in the gateways. Others drive the wholesale movement of voice traffic among the carriers and are used for specialty applications. Each contaisn variations within their own specification.

Common VoIP Codec Protocols
G.729 is the most commonly used codec in VoIP calling is a codec that has low bandwidth requirements but provides good audio quality.

G.711 with only a 1:2 compression and a 64K bitrate for each direction (128K plus some overhead), it is best used where there is a lot of bandwidth available.

G.722 is a high bit rate (48/56/64Kbps) ITU standard codec which, because it is of even better quality of the traditional public switched telephone network (PSTN), it can be used for a variety of higher quality speech applications. But be warned, this standard also requires an adequate amount of bandwidth.

You can assign a different codec to individual phones. You can use medium quality/low bandwidth G.729 codec while the boss and legal department uses the superior quality/heavy bandwidth G.722 codec. The codecs that provide the best quality consume the most data bandwidth, thus there is a trade-off that you need to consider. The easiest way is to ascertain, on a phone by phone basis, whether you want the voice conversation to be:

Do you need some guidance determining which codec to use for your SIP trunks? Contact V1 VoIP right now and we will point you in the right direction. N

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