Hi chickendev,

Yes, if for a client session there are no real-time updates to send and after a configurable timeout no updates have been sent, then a small keep-alive message is sent.
The timeout can be configured both client-side and server-side.
For the server-side please refer to <default_keepalive_millis>, <min_keepalive_millis>, and <max_keepalive_millis> in the lightstreamer_conf.xml configuration file.
For the client-side refer to the API: https://sdk.lightstreamer.com/ls-web-client/8.0.7/api/ConnectionOptions.html#setKeepaliveInterval


For a better control of the connection status, and to allow the server to detect a possible disconnection by the client as soon as possible, it is also possible to activate the reverse heartbeats (sent by the client to the server): https://sdk.lightstreamer.com/ls-web...rtbeatInterval

Regards,
Giuseppe