What is Dial Tone Recovery in Exchange Server 2007

What will happen when exchange database get corrupted and it will take lots of hours to recover the same? Exchange users will get disconnected and will be unable to send/receive the emails. Dial tone allow us to create an empty, or dial tone, database which can be used to send/receive emails while the failed database is in recovery process. Dial tone recovery approach provides basic e-mail services to users. Once the corrupt database is recovered, it will be merged with the dial tone database.

There are several methods of performing a dial tone recovery:-

1. Dial tone and failed database on the same server
2. Dial tone recovery using an alternate server
3. Dial tone recovery using and staying on an alternate server.

All three above methods use the below steps:-

1. Create a new dial tone database to replace with failed database.
2. Restore the old database from backup
3. Replace the dial tone database with the restore database
4. Merge both databases.