Intra-site
replication can be done between the domain controllers in the same site.
Inter-site replication can be done between two different sites over WAN links
BHS
(Bridge Head Servers) is responsible for initiating replication between the
sites. Inter-site replication can be done B/w BHS in one site and BHS in
another site.
We
can use RPC over IP or SMTP as replication protocols where as Domain partition
is not possible to replicate using SMTP