Written by Lets have a look at how Skype integration works in CRM 2013. Its a cool feature.
Lets start with the System Settings where we can configure whether calls need to be triggered via Skype or Lync.
Now, lets have a look at the Contact record with the phone number and it shows the call will be made via Skype.
Just click on the Business Phone number and the skype call pop up will be opened quickly. Check the ‘Do not ask again’ check box for start the call immediately. That’s it boom!
Please like our FB page for getting more updates on Microsoft CRM 2013: https://www.facebook.com/DynamicsCrmGuru
Dynatecon Solutions 
As per my understanding, the Customer fields cannot be used for Skype integration.
The feature is limited to OOB telephone number fields.
Thanks for the article.
Can the custom field be configured for this feature? How can this be done if yes?