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Computer Science Adaptive routing algorithms Factors for decision-making
These algorithms are like intelligent Adaptive algorithms consider several
navigators. They can dynamically adjust factors when choosing a path
to changing network conditions (traffic
(a) Hop count: The number of “hops”
(network devices) a packet needs
congestion, link failures) by continuously
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collecting information and updating routing
A lower hop count often indicates a
tables. This allows them to find the most to traverse to reach its destination.
efficient paths for data packets in real- faster path.
time. They continuously analyse network (b) Distance: The physical distance
conditions like topology (network layout) between network devices, which
and traffic congestion to make informed can be relevant for some routing
routing decisions. This allows them to find protocols.
the most efficient paths for data packets (c) Estimated transit time: An estimate
in real-time, adapting to changes in the of how long it might take for a packet
network. to travel along a particular path.
Types of routing algorithm
There are three main categories of adaptive routing algorithms (see Figure 3.11).
Types of routing algorithm
Adaptive routing Non-adaptive routing Hybrid routing
algorithm algorithm algorithm
Isolated Centralised Distributed Flooding Random Link Distance
walk state vector
Figure 3.11: Types routing algorithms
Adaptive routing algorithm
Centralised routing
In a real real-world scenario, imagine a central traffic control center with a comprehensive
view of the entire road network. This approach is similar: A central entity has complete
knowledge of the network topology and link costs such as congestion levels. Using
this global information, it calculates the optimal path for each data packet.
Isolated routing
This is like navigating using only local road signs without consulting a map or
GPS. In this approach, each network device makes routing decisions based on
information about its directly connected neighbors, without relying on updates from
other devices.
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Computer Science Form 5.indd 146 23/07/2024 12:33
