My home internet service is through Vodafone rural broadband. I have not been able to access Skype (through a Skype app, or via skype.com on a browser), even though all other internet services are working fine.
By the way, it is very annoying that there is no way to email Vodafone support. Life is too short to spend waiting for them to answer a phone call.
Thanks for the suggestion. I think it must be something else, because I could not even load the Skype.com web page, and at the top of the Skpe app on phone/ipad there was an eror message "Unable to sign in. Please check your internet connection and try again". All other internet services were fine, I have been able to make calls over WhatsApp and Facetime through the rural broadband internet connection okay, so it looks like anything to do with Skype was blocked somehow. I could get the Skype app to work fine using the phones data connection over the Spark network. And we have 4G!