Skype is an online chat, voice calling and video calling service that lets users contact other users with a Skype client application. Skype software is available for both computers (Windows and OS X) and smart phones and tablets, including the iPhone, iPad and Android devices. Skype fails: 5 of the worst problems and how to fix them Feb 05, 2015 Troubleshoot problems with Skype for Business Online For dial-in conferencing issues, see Audio Conferencing troubleshooting and known issues. Additional help for Skype for Business Online admin issues. Troubleshoot Skype for Business Online DNS issues. Skype for Business Online users can't communicate with external contacts. Skype for Business and Lync Troubleshooting Guide (downloadable PDF)
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Dell E7240 Microphone not working in Skype - Dell Community
Troubleshooting | Skype Support
Sep 20, 2016