CrystalVoice requires 8 Kbps to 22 Kbps of bandwidth end to end to
support a call. If your bandwidth is less than the 8Kbps required, your call will be dropped. One way delay should be under 250ms, in other words a round trip ping time of 500ms or less. When the ping times are over 500ms, your average is 1200ms, there is enough delay that full-duplex communication is difficult, the connection will seem half-duplex, will break up, or simply end the call. You can test your network connectivity with a free third-party tool
called Qcheck. Qcheck is available at http://www.qcheck.net. You can
install Qcheck on your softphone and your contacts may install this program as
well. You can test the Internet connection between you and your contact.If you detect problems, please contact your ISP to report your issue. Please use the following IP Address: 206.112.96.154, when testing your bandwidth using Qcheck. In addition to testing your bandwidth, please follow these instructions: Please send us your CrystalVoicePhone.ini file. It is located in Mycomputer>Explore>C:>Program Files>CrystalVoice>Application>CrystalVoicephone.ini.You may send this file to support@crystalvoice.com. We will update this file and send it back to you. | 
