I have configured kamailio as Ims server with pcscf,icscf,scsf and hss in 4 different vms . After that I use zoiper client for testing the call flow . Registration is successful .It goes via 

UE -> Pcscf -> icscf -> scscf and returns back with 200 OK . Registration is happening with authentication from hss .

When I make an INVITE , it goes from 

UE -> PCSCF -> SCSCF -> ICSCF -> SCSF and s-cscf gives 403 - Domain not served to icscf and i-cscf returns to p-cscf with the same error .

I am not seeing any errors in scscf and i-cscf .

In pcscf , I am seeing an error like 

What should I do? Kindly advise.

I am struggling with this issue for a week.kindly do the needful.

Version - kamailio - 5.3.3 

I need a normal call flow to be established between two clients.kindly help .