220 Nortel IP Softphone 2050• sound devices handling• network voice data flow processing• voice quality improvement• Dual-tone Multifrequency• Telchemy VQMon libraryFor more information about configurable settings in the Sound Settings tab,see IP Softphone 2050 User Guide (NN43119-101).Voice encoding and decodingGIPS supports G.711 A-law, G.711 μ-law, and g.729 codecs.Sound devices handlingYou can change the volume level for input and output devices in the Sounddevices tab.Network voice data flow processingGIPS uses GQoS API to modify the DiffSERV code point and the 802.1pmarker bits (when supported) by setting a GQoS service level that theWindows operating system maps to a Diffserv code point and to a 802.1psetting. According to Microsoft Developer Network (MSDN), these settingsare set to the following recommended values for voice applications• ToS DSCP field is set to 0x28• 802.1p priority field is set to 5Voice qualityGIPS implements NetEQ, Echo Cancellation, and Noise Suppressionfeatures. NetEQ feature is an integral part of all GIPS codecs. GIPSNetEq software compensates for up to 30% lost packets in a LAN or WANenvironment.The GIPS Echo Cancellation and Noise Suppression features improve thequality of conversations by removing echo and background noise.You can enable or disable Echo Cancellation and Noise Suppressionfeatures in the Sound Settings tab.Dual-tone MultifrequencyGIPS implements Dual-tone Multifrequency (DTMF) tones playing andsends in accordance to RFC 2833. DTMF supports event numbers from1 to 16.Nortel Communication Server 1000IP Phones FundamentalsNN43001-368 02.01 StandardRelease 5.0 7 December 2007Copyright © 2003–2007, Nortel Networks.
