Configuring Audio Features8414. Enter the desired value in the Handfree Send Volume (-50~50) field.5. Click Confirm to accept the change.A dialog box pops up to prompt that the settings will take effect after a reboot.6. Click OK to reboot the phone.Audio CodecsCODEC is an abbreviation of COmpress-DECompress, capable of coding or decoding a digitaldata stream or signal by implementing an algorithm. The object of the algorithm is to representthe high-fidelity audio signal with minimum number of bits while retaining the quality. This caneffectively reduce the frame size and the bandwidth required for audio transmission.The audio codec that the phone uses to establish a call should be supported by the SIP server.When placing a call, the IP phone will offer the enabled audio codec list to the server and thenuse the audio codec negotiated with the called party according to the priority.The following table lists the audio codecs supported by each phone model:Phone Model Supported Audio Codecs Default Audio CodecsSIP-T48G/T46G/T42G/T41P/T29G/CP860G722, PCMA, PCMU, G729, G726-16,G726-24, G726-32, G726-40, iLBC,G723_53, G723_63G722, PCMA, PCMU,G729SIP-T40P/T27P/T23P/T23G/T21(P)E2/T19(P) E2G722, PCMA, PCMU, G729, G726-16,G726-24, G726-32, G726-40, iLBCG722, PCMA, PCMU,G729SIP VP-T49GG.722.1c(48kb/s), G.722.1c(32kb/s),G.722.1c(24kb/s), G.722.1(24kb/s), G722,PCMU, PCMA, G729, G726-16, G726-24,G726-32, G726-40, iLBC, G723, OpusG.722.1c(48kb/s),G.722.1c(32kb/s),G.722.1c(24kb/s),G.722.1(24kb/s), G722,PCMU, PCMA, G729
