This paper presents the Virtual Mobility Domain concept built to provide mobility management in a newly proposed tiered internetworking model. The proposed mobility management scheme is distinct from others by not using IP addressing, the classic IP routing protocols and providing collaborative mobility management mechanism. We investigate the handoff performance of the proposed scheme when it is deployed in varying tiers of an Autonomous System. The comparative OPNET simulation study shows that, in most cases, the proposed scheme manages a handoff in 99%, 98% and 38% less time and with 80%, 32% and 25% less signaling overhead as compared to Mobile IPv6, Hierarchical Mobile IPv6, and Proxy Mobile IPv6, respectively (see Table II).