For instance, callers can be instructed to use the directory to find the person they are
trying to reach. But there is one way to handle this so that callers do not even need to
know that the extension numbers changed. Alternate extensions can be used to allow
subscribers to retain their old three-digit extension numbers in addition to their new
four-digit number. This way, callers who know the new four-digit number can enter
that to reach a given subscriber, and callers who know only the old three-digit
extension number can still use that to reach the same subscriber.
It is important to note that alternate extensions ...
Become an O’Reilly member and get unlimited access to this title plus top books and audiobooks from O’Reilly and nearly 200 top publishers, thousands of courses curated by job role, 150+ live events each month, and much more.