System requirements for FSCM credit management

Hello,

We have implemented FI - AP, GL and CO as phase 1 (ECC6.0)

and not implementing FSCM and AR as phase 2.

As I understand FSCM credit management exchanges information using XML interfaces.

Is it mandatory to have SAP XI for the interfaces to work ?

Are there any alternatives to make FSCM work without XI ?

Thanks,

Sushil Joshi