[c-nsp] Different Supervisor in 7609 + High Availability (SSO + NSF + GR)

[cisco-pe]

Dears,
Is it possible to use two different supervisor in one 7609? (WS-720-3B and
RSP 720-3C)
At this moment we are using a number of 7609 with only one supervisor
(WS-720-3B), and we want to implement HA using a second supervisor (RSP
720-3C).
Another question: We are using the GE port on the main supervisor for the
Uplink connection, if we use the GE interface on the second supervisor, is
it possible to use this link to implement load balancing ?
Or this link only will be active when the supervisor change from stand-by to
active??

Brgds
JC