Difference between Adaptive and Non-Adaptive Routing algorithms

Prerequisite – Classification of Routing Algorithms

1. Adaptive Routing algorithm:
Adaptive routing algorithm is also called a dynamic routing algorithm. In this algorithm, the routing decisions are made based on network traffic and topology. The parameters which are used in adaptive routing algorithms are distance, hop, estimated transit time and count. 

The adaptive routing algorithm is of three types –

• Centralized algorithm
• Isolation algorithm
• Distributed algorithm

2. Non-Adaptive Routing algorithm:
Non-adaptive routing algorithm is also called a static routing algorithm. In a non-adaptive routing algorithm, the routing decisions are not made based on network traffic and topology. This algorithm is used by static routing. Non-adaptive routing algorithms are simple as compared to Adaptive routing algorithms in terms of complexity. 

The non-adaptive routing algorithm is of two types –

• Flooding
• Random walks

Difference between Adaptive and Non-Adaptive Routing algorithms :

S. No.	Adaptive Routing algorithm	Non-Adaptive Routing algorithm
1.	An adaptive algorithm involves routers for exchanging and updating router table data.	A non-adaptive algorithm involves a network administrator for the manual entry of the routing paths into the router.
2.	This algorithm creates a routing table based on network conditions.	Whereas this algorithm creates a static table in order to determine when to send packets and which node.
3.	This algorithm is used by dynamic routing.	Whereas this algorithm is used by static routing.
4.	In adaptive routing algorithm, the routing decisions are made based on network traffic and topology.	Whereas in a non-adaptive routing algorithm, the routing decisions are not made based on network traffic and topology.
5.	Adaptive routing algorithms are more complex as compared to non-adaptive routing algorithms in terms of complexity.	While non-adaptive routing algorithms are simple in terms of complexity.
6.	In adaptive routing algorithm, the routing decisions are not static tables.	While in non-adaptive routing algorithm, the routing decisions are static tables.
7.	Adaptive routing algorithm is categorized into distributed, centralized and isolation algorithm.	Whereas non-adaptive routing algorithm is categorized into random walks and flooding.
8.	Adaptive routing algorithm is more used as compared to non-adaptive.	Whereas non-adaptive routing algorithm is comparatively less used.
9.	The dynamic protocols are employed to update the routing table and determine the best route between the source and destination computers.	The manual setup is performed for establishing an optimal path between the source and destination computers.
10.	It is mostly used for- Open, Complex network topologies	It is mostly used for- Simple, Closed network topologies
11.	Purposes- Enhancement in network performance Prevents packet delivery failure Aid in controlling congestion	Purposes- It enables fine-grained control over packet paths. Suited for reliable networks with stable loads

Advantages of Adaptive Routing Algorithms:

1. Dynamic: Adaptive routing algorithms can adjust to changing network conditions, such as traffic congestion, link failures, and topology changes, by selecting a better path for the data packets. This results in better network performance, higher throughput, and reduced latency.
2. Load Balancing: Adaptive routing algorithms can distribute network traffic across multiple paths to avoid congestion and ensure that all network links are utilized efficiently.
3. Fault Tolerance: Adaptive routing algorithms can reroute data packets around network failures, which enhances network availability and reliability.
4. Better Performance: Adaptive routing algorithms can provide better network performance by selecting the shortest or the least congested path for the data packets.

Disadvantages of Adaptive Routing Algorithms:

1. Complexity: Adaptive routing algorithms are more complex than non-adaptive algorithms, which makes them harder to implement and maintain.
2. Overhead: Adaptive routing algorithms require more processing power and memory to execute, which can lead to increased overhead and resource utilization.
3. Routing Loops: Adaptive routing algorithms may sometimes result in routing loops, which can cause data packets to be stuck in the network indefinitely.
4. Delay: Adaptive routing algorithms may introduce additional delay in the network due to the time required to calculate the best path for each data packet.

Advantages of Non-Adaptive Routing Algorithms:

1. Simplicity: Non-adaptive routing algorithms are simple to implement and maintain, which reduces the cost and complexity of the network infrastructure.
2. Low Overhead: Non-adaptive routing algorithms require minimal processing power and memory to execute, which reduces the overhead and resource utilization.
3. Avoid Routing Loops: Non-adaptive routing algorithms are less likely to result in routing loops, which reduces the chances of data packets being stuck in the network indefinitely.
4. Fast: Non-adaptive routing algorithms can provide faster routing decisions since they do not require the calculation of the best path for each data packet.

Disadvantages of Non-Adaptive Routing Algorithms:

1. Inefficient: Non-adaptive routing algorithms may select suboptimal paths for the data packets, which can result in congestion, longer latency, and reduced throughput.
2. Inflexible: Non-adaptive routing algorithms cannot adjust to changing network conditions, which may result in network failures, reduced performance, and increased latency.
3. Unresponsive: Non-adaptive routing algorithms cannot respond to network faults, which may result in data packet loss and reduced network availability.
4. Uneven Traffic Distribution: Non-adaptive routing algorithms may lead to uneven traffic distribution, which may result in some links being underutilized while others are congested.