Migration of TCP connections is done by request of the client. When the client requests a migration to another server, the state of the TCP connection is copied to the new server.

There are two main problems to solve when moving a connection:

• Moving the IP Address. The IP address of the connection must remain unchanged after the migration. If the client notices any change, it will reset the connection. The main problem of moving the IP Address is keeping the same IP address for all the other connections that will remain in the original server.
• Moving the TCP Connection State. This allows the new server to continue the connection transparently. The problem of moving the TCP state is easier than the IP Address, because moving the state of a connection does not affect other connections.