#### To Enable Availability for the SIP Container

1. In the tree component, click the Configurations node and select the desired configuration.
2. Click Availability Service.
3. Click the SIP Container Availability tab.
4. Enable or disable availability of SIP Session Persistence. By default, this check box is enabled.
5. If availability is enabled, change other settings as follows:
   Persistence Type

     Specifies the session persistence mechanism for SIP applications that have availability enabled. Allowed values are as follows:

     `memory`

       Specifies no persistence.

     `file`

       Specifies the file system.

     `replicated`

       Specifies memory on other servers.

   Persistence Frequency

     Applicable only if the Persistence Type is `replicated`.

     In this field, you can specify how often the session state is stored.

     `sip-transaction`

       Indicates that the session state is stored at the end of each sip transaction. This mode provides the best guarantee that the session state is fully updated in case of failure.

   Persistence Scope

     Applicable only if the Persistence Type is `replicated`. Specifies how much of the session object and how often session state is stored. Allowed values are as follows:

     `session`

       The entire session state is stored every time. This mode provides the best guarantee that your session data is correctly stored for any distributable SIP application. This is the default.

     `modified-session`

       The entire session state is stored if it has been modified. A session is considered to have been modified if `HttpSession.setAttribute()` or `HttpSession.removeAttribute()` was called. You must guarantee that `setAttribute()` is called every time an attribute is changed. This is not a Java EE specification requirement, but it is required for this mode to work properly.

     `modified-attribute`

       Only modified session attributes are stored. For this mode to work properly, you must follow a few guidelines:

       - Call `setAttribute()` every time the session state is modified.

       - Make sure there are no cross-references between attributes. The object graph under each distinct attribute key is serialized and stored separately. If there are any object cross-references between the objects under each separate key, they are not serialized and deserialized correctly.

       - Distribute the session state across multiple attributes, or at least between a read-only attribute and a modifiable attribute.

   Repair During Failure

     Click Enabled if a forward and reverse repair should be performed on an instance that has joined the cluster.

6. If necessary, add or delete any additional properties.
7. Click Save.
8. Restart the server instance.