While logged into the Notes Instant Messaging client, your previously established connection with the Sametime server is lost. How and for how long will the Notes client attempt to reconnect with the Sametime server?
The Notes 6.5.x client does not perform any reconnect requests. This issue was reported to Quality Engineering as SPR# GMAA6NDGWQ and has been addressed in the Notes 7 code stream.
In Notes 7.0, the client will continuously perform a reconnect request every 30 seconds until a connection can be established with the Sametime server (specified in the users Location document) or the reconnect request has been cancelled by the user.
The Notes 7.0.2 and newer releases (including 8.0.x Basic and 8.5 Basic), the client will perform 20 reconnection requests to the Sametime server (specified in the users Location document). Each request is made at a 30-second interval thus yielding a total reconnect request time of 10 minutes.
Note: The reconnection values are hard coded and cannot be reconfigured or manipulated in any way.
via IBM – How the Notes Instant Messaging client attempts to reconnect with a Sametime server when an established connection is lost.