Assisted Replication with VXLAN Access Points
Access points (APs) have LTEPs defined on each AP, which connect to one, and only one, replicator. Unicast and BUM traffic traverses the same path up the VXLAN tunnel to the replicator. Unicast traffic is forwarded out the correct path towards the destination similar to the way RIOT works (see Routing in and out of Tunnels (RIOT)), but in this case the VXLAN traffic is not routed in/out, but rather switched in/out. BUM traffic is replicated to all other APs on the VNI, as well as local access ports. The restriction of a single replicator allows the replicator to have local access ports without negative effect.
Similar to regular Assisted Replication functionality, the role of the replicator in an AP topology includes replicating BUM traffic on behalf of the sending VXLAN VTEP (AP in this case). The APs do not have the necessary hardware or CPU cycles to perform the VXLAN BUM replication, so the replicator offloads the work load from the AP. At the same time, the replicator is also the only RTEP known by the APs, so all unicast VXLAN traffic is also forwarded through the replicator to its ultimate RTEP destination.