Open Stack

Hello,
When there are periods of idle activity in the Horizon WebUI of
OpenStack, I am kicked off from it and redirected to the login
screen of it. It is usually occurs after several minutes of idle
activity, something like 10 or 15 minutes or more.
Is there a way to control this and make this interval longer ? or is
it not an OpenStack Horizon tunable setting and depends simply on
reset of the connection done by non OpenStack mechanism ?

Regards,
Rami