System Settings 257Audio Settings Audio Settings enable you to affect the network impact of your audiopackets by enabling or disabling compression, silence suppression, andecho suppression. You can enable and disable these settings for the entiresystem and then override the system-wide setting for individual devices.Compression OverviewBefore voice traffic can be transmitted over a digital network, the audiowaveform, an analog signal, must be encoded into a digital format. Thedigitized audio is packetized and delivered over the network to adestination, and then decoded back into a voice waveform. Softwarecalled a codec (coder/decoder) converts the audio information betweendigital and analog formats.Digitized audio formats have different properties. Each format representsa compromise between bandwidth and audio quality, that is, high qualityaudio typically requires more network bandwidth. Compressing thedigitized audio data can conserve bandwidth with little compromise inaudio quality, but compression requires increased processing overheadwhen encoding and decoding the audio information. Too muchprocessing overhead can introduce delay.TransferThrough AutoAttendantIf the calling party calls the main Auto Attendant number, and theAuto Attendant transfers the call to the extension of choice (or tothe default destination), then the called party sees the samebehavior as if the call had been transferred. That is, the Call Timercount at the transfer destination starts when the called partyanswers the call.Bridged Calls For bridged calls, the Call Timer display depends on the off-hookindicator. For example, if an administrative assistant answers thephone, puts the call on hold, and a site manager picks up, themanager sees the counter start from zero. However, if theadministrative assistant puts the call on hold and retrieves it later,then the administrative assistant would see that the NBX system hasdefined the Call Timer display for normal hold.As another example, suppose the administrative assistant puts thecall on hold, the manager picks up the call, and then puts the callon hold. At this point, the administrative assistant picks up the call.In this case, the administrative assistant sees the Call Timer displayas if the administrative assistant had picked up a new call.Table 33 Call Timer BehaviorsFeature Description
