Expand Configuration and Management Manual (H06.21+, J06.10+)

Planning a Network Design
Expand Configuration and Management Manual — 529522-013
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Topology Limitations
Tri-Star Topology
Used for ServerNet clusters, the tri-star topology connects three star topologies. Each
star contains a cluster switch. The three cluster switches are connected by fiber optic
cables, each of which can be up to one kilometer in length. This topology can be used
for up to 24 nodes. For examples of this topology, see Section 4, Planning for
ServerNet Clusters.
Tree Topology
In a tree topology, the shape of the network is that of an upside-down tree that has
branches and subbranches. Network reliability in tree networks depends on the
reliability of each connection.
Bus Topology
A bus topology is a common local area network (LAN) topology that consists of a line
of cable with nodes connected along the cable’s entire length.
Mesh Topology
In a mesh topology, each node is connected to every other node in the network. A
mesh network is very reliable because it contains multiple paths between every node.
The major disadvantage of a mesh topology is its high communications cost.
Mixed Topology
A mixed, or unconstrained, topology is a combination of some or all the above-
mentioned topologies.
Topology Limitations
Expand networks are not limited to any particular network topology. However, the
resource limitations described below can affect your network topology design.
Expand Line-Handler Process Limitation
Because each system in an Expand network can contain a maximum of 255 Expand
line-handler processes, each node can have a maximum of 254 neighbors. This
restriction limits the size of any network configured as a fully connected mesh to 255
nodes.