It´s a while ago now I setup a Clarrion with iSCSI, but I´m pretty sure it was:
SPA1 - SUBNET1
SPA2 - SUBNET2
SPB1 - SUBNET1
SPB2 - SUBNET2
If I remember correct there have been also a good documentation in the manuals, which have been shipped with the Clarrion.
Regards,
Mario