Hello just wondering there are 5 employees using the Zoiper app and I have noticed that two of those phones have had errors with registration. When I downloaded the app onto their phones everything worked really well and then a couple of days later one of the phones went offline and said that there was a registration failure 411 I deleted the account and reset passwords and got it working again. Now a second phone has a registration error saying that the DNS has no results 923. After a few hours it came back online but I am just wondering if there is a way to prevent this from reoccurring?