10 IBM Tivoli Remote Control Across Firewalls
1.1.4 Parent-Child concept
The hierarchy of the components of either the Tivoli Firewall Security Toolbox or
the Remote Control Proxies (either RC Target Proxy or RC Controller Proxy) is
presented in terms of a Parent-Child relationship. Such hierarchy is a subset of
the whole Tivoli Top-Down hierarchy. It means that the starting p oint is the TMR
Server and the ending point is the Endpoint. The components close to the TMR
Server will be Parents and the ones close to the Endpoints will be Children.
However, some components could, at the same time, be a Child and a Parent, as
they are just in between the Parent-Child hierarchy. You must also notice that a
Parent could have more than one Child but that a Child could only have one
Parent.
As the Endpoint Proxy, which simulates Endpoints, is the closest element from
the TMR Server, it is a Parent and, as it is directly connected to a Tivoli Gateway,
it could not have any Parent. As the Gateway Proxy, which simulates a Tivoli
Gateway, is the closest element from the Endpoints, it is a Child and as it the
most closest component from the bottom of the hierarchy, it could not have any
Child. A Relay could be either a Parent or a Child. When it is connected to an
Endpoint Proxy or to another Relay, it becomes a Child of those components. In
another way, when a Gateway Proxy or another Relay connects to a Relay, this
one also becomes a Parent for these components.
In the case of Remote Control Proxies being installed on top of the Tivoli Firewall
Security Toolbox components, the RC Proxy (either Target or Controller Proxy)
installed on the Endpoint Proxy is a Parent of Relays or other RC Proxies. The
RC Proxy installed on the Gateway Proxy is a Child of an RC Proxy installed on
an Endpoint Proxy or a Relay. As no Remote Control components could be
installed on the Relay, an RC Proxy could only be either a Parent or a Child, but
not both at the same time.
If the Remote Control Proxies are installed as Standalone components, you have
to decide on the Parent-Child role for each of the Proxies (Target and Controller
Proxies). For configuration improvement, it is advised to configure the Target
Proxy as the Parent and the Controller Proxy as the Child. This is because
connection requests to the Target Proxy are done by the RC Controller. So, this
request is always forwarded by the RC Target Proxy to the RC Controller Proxy.
In this case, to logically respect a Top-Down hierarchy and to improve
performance for the request, the RC Target should be the Parent.
Figure 1-1 depicts the Top-Down Proxy hierarchy when Remote Control Proxy
components are installed on top of the Tivoli Firewall Security Toolbox.