The femto-cell is required to communicate with the Initial SeGW after it has been energized.
In order to provide secure communications between the femto-cell and the Initial SeGW, an IPSec tunnel is established between the two entities.
In the absence of a CGW, the femto-cell would make this request to the Initial SeGW via the IPSec tunnel established previously.
Section 5.1.1 of  requires that even if the Serving SeGW is the same as the Initial SeGW, the tunnels are still destroyed.
The femto-cell is required to communicate with the Serving SeGW after the femto-cell has gone through the initialization and provisioning steps.
After this step, the femto-cell establishes an IPSec tunnel with the Serving SeGW. This is the same procedure that was followed by the femto-cell when it formed an IPSec tunnel with the Initial SeGW.
Once these tunnels are established, they will be used "forever" to provide secure communication between the femto-cell and CGW and the CGW and the Serving SeGW.