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Beta Draft Confidential
Configuring PNNI Routing
PNNI Routing Protocol Overview
ATM Services Configuration Guide for CBX 3500, CBX 500, GX 550, and B-STDX 9000
1/19/05
21-9
shows an example of a three-tiered PNNI routing hierarchy, with eight
lower-level nodes divided into four peer groups (PG1 - PG4). Nodes with links to
other peer groups act as border nodes. A node acting as the LGN is also a PGL of the
child peer group at the next lower level.
Figure 21-1.
Three-Tiered PNNI Routing Hierarchy Example
As the parent of its child peer group, the LGN joins the next highest peer group in the
hierarchy, which can be made up of other parents (that is, LGNs) representing other
child peer groups. In turn, the members of the next highest peer group in the hierarchy
choose a PGL, which summarizes information to the LGN in the hierarchical chain,
forming multiple peer group levels.
LGN
LGN
Legend
N = Lowest-level Node
LGN = Logical Group Node
PG = Peer Group
PG1
PG5
PG7
PGL = Peer Group Leader
N
N
Border Nodes
LGN
LGN
PG2
PG3
PG4
PG6
N
N
N
LGN
LGN
PGL
PGL
Border Nodes
Border Nodes
N
N
N
PGL
Note – Lucent switches support a maximum of 400 nodes and 1000 links per peer
group. However, Lucent recommends a maximum peer group size of 100 nodes and
500 links to take advantage of the significant scalability provided by PNNI routing
hierarchy.
Summary of Contents for CBX 3500
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