Hierarchy In An E-Iisp Network; Hierarchical Atm Addressing - 3Com CoreBuilder 7000 Operation Manual

Hierarchy in an
E-IISP Network
A
A1
A15
A12
Hierarchical ATM
Addressing
E-IISP also introduced the concept of hierarchy in a network design.
Using E-IISP, most 3Com ATM networks are based in the ATM address of
47.0.0.0.0.0.3c.0.0.a* i.e., utilizing the last four bytes of the switch
portion of the ATM address. In the ATM address space, hierarchy
translates into a tree structure as shown in Figure 10. The network core is
designated as the roots of the network and the other switches
subordinate to them are attached as branches. In Figure 10, A, B and C
are the switches that comprise the network core. Each subordinate
switch can also have switches attached to it. As you progress down the
hierarchy, the node name (or ID) is lengthened to include the parent
node. Finally, all of the roots (A, B, and C) are connected together to
ensure that every node can reach every other node.
Network Core (Root of Hierarchy)
B
A2
B7
B71
Figure 10 Connecting Switches in a Hierarchical Topology
This type of topology is well-suited for installation in a group of buildings.
Each of the trees A, B, C would be installed in a separate building where
the root node would be located in the basement and the branches
distributed throughout the floors.
Figure 11 shows the components of the ATM address of a switch.

Hierarchy in an E-IISP Network

C
C4
B8
B84
55
C9
Edge Devices
(Branches)