iSCSI using IPSEC

[Rahul Gupta <Rahul.gupta@dcmtech.co.in>]

Hi all,
I am new developer on iscsi & ipsec . I have a small basic query. 

1) Does Ipsec needs to be developed at the iscsi level and incorporated as a
part of iscsi or it is a standalone entity ???

2) How does iscsi utilizes the ipsec functionality ..?? ( Since Ipsec is
between TCP and IP in the stack while iscsi is above TCP...)

Regards
Rahul Gupta