I recently converted a customer from 4 to 10 digit extensions in their dialplan. All phones were IP 4620 and I advised customer that all phones would need to be logged in after the extensions were changed. Turns out all the phones re-registered by themselves and reflected the new 10 digit extension. I am at a loss to explain how this occurred. I have more locations to convert and having an answer to this would cut down on the manpower needed onsite if we do not need to touch each phone with extension and password. Any help would be greatly appreciated. Thanks!