Access Groups and Network Enablers
Network Enablers (NEs) are deployed in access groups, with all NEs in all access groups being fully meshed with all engines.
Each NE is aware only of other NEs in the same access group. This means that NEs can cross link only with NEs within the same access group. When configuring cross-links, if there are an even number of NE replicas in an access group, they configure in cross-link pairs, for example, NE1 links to NE2 and vice-versa. If there are an odd number of NE replicas in an access group, they configure in a ring so that, for example, NE1 links to NE2, which links to NE3, which links back to NE1. In multi sub-domain deployments, the NEs in an access group link (for route-cache updates) only to the TRA-RTs in the same access group.