h1. How long will be down time when moving service to other server without moving IP address

Let's suppose, you need to move all provided services from one server (_server A_) to another (_server B_).
IP address is not moved.
Most often this procedure is done to switch hoster.
In case if you move to other server inside the same hoster - consider another way, see [[How long will be down time when moving IP address]].

Procedure of work we perform is as follows:

1. Add _server B_ into cluster with _server A_.
Work time and down time is described in section [[How long will be down time when setting up replication]].

2. Notify suppliers about adding IP address of _server B_ to a list of authorized IP addresses.

3. In case if you use SIP registration on suppliers - registration will work simultaneously only from one of your servers.
Supplier won't allow you to register from 2 servers simultaneously using the same login.
When you move your customers to _server B_ there will be situation when part of customers continues using _server A_, and other part is starting using _server B_.
Thus to support zero down time for your customers +you should foresee reserve routes+, which will work on both servers simultaneously.
For peers, on which Smartswitch registers, you need to specify on which of cluster nodes the peer should be active.
This could be done in menu Terminator -> edit -> Lists -> Nodes -> add some node.
In case if Smartswitch will register from both nodes - registrations will interfere with each other at your supplier's side, and your supplier will allow calls either from _server A_ or from _server B_ randomly.

4. Start moving customers by notifying them your new IP address of _server B_.
In case if customers are connected by your domain name - change IP address at your DNS zone.

5. During customers migration, you should perform all operations in web GUI on _server A_.

6. After all customers have moved to _server B_ - you notify us and we delete _server A_ from cluster.
Work time: 30 minutes.
Downtime: 10 sec.
After this step all operations on GUI should be performed on _server B_.

7. Now technically you can decline old _server A_ at hoster side and stop paying for it to hoster.
*Attention!* We recommend you to decline old server after all your originators have paid all invoices for the period while traffic passed through old server.
Otherwise some useful data could be lost on old server which could have helped to solve dispute or understand why there is a difference.

[[Сколько будет простой при переносе сервиса на другой сервер без переноса IP адреса|Русский перевод]]