Unity Async Replica Interface

Hello,

I try to configure an async replica between two Unity systems, and I have some doubts.

1) Is it possible to use only one port per system? Or is it mandatory to use minimum two ports per system (one port per SP in each system)?

2) If i´ll have configured one link aggregation with some interfaces, and these link aggregations are used for a production NAS traffic (with VLANs). Is it possible to use this link aggregation for replica interface (with a new vlan tagging for replica)?

3) I understand async replica back to back (without switched network between storage) it is not supported, but they can use in some cases. In that case, is it possible, for example, SPA-port1 in one system and SPB-port1 in the other system (cross SP connection)? Or is it necessary that use the same SP and the same port in these SP (example SPB-port1 and SPB-port1)?

Thanks in advance!