TCP/IP Tutorial and Technical Overview - IBM Redbooks

The MPOA solution has the following benefits over both Classical IP (RFC 2225)
and LAN emulation solutions:
► Lower latency by allowing direct connectivity between end systems that can
cut across subnet boundaries. This is achieved by minimizing the need for
multiple hops through ATM routers for communication between end systems
on different virtual LANs.
► Higher aggregate layer 3 forwarding capacity by distributing processing
functions to the edge of the network.
► Allows mapping of specific flows to specific QoS characteristics.
► Allows a layer 3 subnet to be distributed across a physical network.
2.11.2 MPOA logical components
The MPOA solution consists of a number of logical components and information
flows between those components. The logical components are of two kinds:
MPOA server MPOA servers maintain complete knowledge of the MAC
and internetworking layer topologies for the IASGs they
serve. To accomplish this, they exchange information among
themselves and with MPOA clients.
MPOA client MPOA clients maintain local caches of mappings (from
packet prefix to ATM information). These caches are
populated by requesting the information from the appropriate
MPOA server on an as-needed basis.
The layer 3 addresses associated with an MPOA client
represent either the layer 3 address of the client itself, or the
layer 3 addresses reachable through the client. (The client
has an edge device or router.)
An MPOA client will connect to its MPOA server to register
the client's ATM address and the layer 3 addresses
reachable by the client.
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