ADTRAN 1950859L1 User Manual

ADTRAN 1950859L1 User Manual Manual pdf 48 page image

Appendix A: Troubleshooting ADTRAN IP SoftPhone User Manual48 Copyright © 2006 ADTRAN, Inc. 61950859L1-1AThere are several factors that may affect sound quality when using the ADTRAN IP SoftPhone. Theseinclude the quality of the network connection, quality of the network device, and headset model. Some ofthe common problems experienced are given below, along with useful tips on how to minimize their effect.Audio contains pops at loud points in voicePopping sounds are a symptom of over-modulation. Ask the other party to decrease their microphoneslider and/or adjust the microphone gain.Audio contains bothersome background noiseSignificant background noise can be due to the level of the silence threshold. Have the other party adjusttheir silence threshold, which they can do by running the Tuning Wizard.Audio sounds choppy in a conferencePoor conference audio may be caused by upload bandwidth limitations. For example, some sites have1 Mbps download bandwidth, but only 128 kbps upload bandwidth. Under such conditions, try multiplehosts for the conference, or have all participants disconnect and switch to a lesser bandwidth audiocompression CODEC such as G.729.Poor soundPoor or scratchy sound is a symptom of a problem with network connections or a faulty network card. Thefollowing issues could contribute to poor sound quality.• There may be packet loss on the IP network. Check the network performance, latency, andthroughput. A 200 millisecond round trip latency as determined from a ping should deliver goodaudio quality.• Older network devices may have performance problems. Make sure to use the latest driver.There is an echoThe following tips may be useful for reducing echo heard during the conversation.• Try using a headset plugged into the sound card. Another suggestion is to use a USB-enabledheadset, which bypasses system sounds by acting as its own sound device.• If using a boom type headset, note that some boom headsets can create feedback between the boommicrophone and the headset earpiece.• The microphone volume may not be muted in the playback section of Windows audio controls.When configuring sound, check the Windows volume control setting.• Echo will occur if the microphone can pick up sounds coming from the speakers used for thesoftphone call (when not using an integrated headset).• The microphone level might be too high or the amplifier might be turned on in the generic Windowsaudio controls.One-way AudioIf a firewall restricts incoming connections, the result can be one-way audio. Configure the ADTRAN IPSoftPhone to use the service provider’s Outbound Proxy (if available), as explained under Firewall andNAT Issues on page 46.