Network Topology vs. Redundancy
Protocols
UM RedundConfig RSPL
Release 2.0 02/2013
9
1 Network Topology vs.
Redundancy Protocols
When using Ethernet, an important prerequisite is that data packets follow a
single (unique) path from the sender to the receiver. The following network
topologies support this prerequisite:
Line topology
Star topology
Tree topology
Figure 1: Network with line, star and tree topologies
To ensure that the communication is maintained when a connection fails, you
install additional physical connections between the network nodes.
Redundancy protocols ensure that the additional connections remain
switched off while the original connection is still working. If the connection
fails, the redundancy protocol generates a new path from the sender to the
receiver via the alternative connection.
To introduce redundancy onto layer 2 of a network, you first define which
network topology you require. Depending on the network topology selected,
you then choose from the redundancy protocols that can be used with this
network topology.