Hi neutron experts

Have a cloud built with multiple network segments (RPN) . (kolla-ansible,  openstack ussuri),

things are running OK (on the network level):

networks have DHCP agents ok (os network agent list --agent-type dhcp --network $networkID )

all network segments are listed in Host Aggregates

BUT if I run through all the existing segments ,

NONE have a (compute service) inventory declared for each segment IPv4 subnet

i.e

returns no output. (official doc on RPN says this should exist)

What feature may not function if this inventory is missing ?

I don't quite understand what role this IPv4 subnet compute service inventory plays here (during placement? port declaration ?)

thanks

Andrew