Abstract: A method of setting up a reverse channel across a firewall, wherein the firewall is configured to enable entities internal to the firewall to originate connections across the firewall to entities external to the firewall but to block connections originating from entities external to the firewall, the method comprising the steps of: (a) using a server internal to the firewall to originate a connection across the firewall to a reverse channel proxy external to the firewall, the server and reverse channel proxy each having a role in relation to the connection, the server having a client role and the reverse channel proxy having a server role; and (b) initiating a role reversal process whereby the reverse channel proxy changes its role to a client role and the server changes its role to a server role.