Centralized routing vs distributed routing

Routing involves choosing the paths to send network traffic and sending packets along the selected subnet.

Centralized routing model: in which routing is performed centrally using a centralized database.

Distributed routing model: is a routing model, which deals with the realization of a routing using a distributed database.

What is centralized routing ?

  • In this model routing is performed centrally using a centralized database.
  • The routing table is kept on a single “central” node, which must be consulted when other nodes have to make a routing decision.
  • Centralized database has a global view of the network.
  • Resources saver: Routing table develops only on one Node, Others uses it without calculating itself like distributed routing.

Disadvantages of centralized routing:

  • If one node breaks down, it is out of control to find the defect.
  • The routing table node has Vulnerable one.
  • In-case of routing table changes, previous network capacity is “wasted”. No routing will be assigned from previous record.
  • Does not reflect changing network conditions such as computers that are overloaded by many messages

What is distributed routing ?

  • In the distributed routing model, each node maintains a separate routing table.
  • The distributed routing model is excellent for areas that can be identified as fully opaque.
  • The main reason for this is that the constraints on degradations play no role in routing in the aforementioned areas.
  • The distributed routing model is highly consistent with the existing Internet distributed routing philosophy.

Disadvantages of Distributed Routing:

  • Each node calculate the routing table itself, which leads to waste the resource.

What is the difference between centralized routing and distributed routing?

Centralized RoutingDistributed Routing
The centralized routing model performs routing using a centralized database.The distributed routing model using a distributed database (routing calculated by every node itself).
A central node contains the routing table in the centralized modelWhile each node maintains a routing table in the distributed model
Since most information does not change often, many believe that this information can be stored in a centralized database.
The pre-calculations required for restoration can take advantage of the global information available in a centralized database.The distributed routing system, we cannot count on the centralized system to assume responsibility for the on-demand calculation of the recovery paths for each of the faulty light paths (when detecting an expected failure).
Centralized routing is most appropriate in specific areas with systems providing DWDM (dense wavelength division multiplexing) transmission. The distributed routing model is highly consistent with the existing distributed Internet routing philosophy.

FAQ’s – Centralized Routing vs Distributed Routing

If a node is breakdown what will happen?

Centralized Routing: This routing model is complicated as one node breakdown, it can be headache to find the problem.
Distributed Routing: In the event of a breakdown, we can count on the distributed routing system to assume responsibility for the calculation at the request of a recovery path for each of the light paths that have failed (even to the point of detecting an expected failure).

Where Centralized Routing Applicable:

Centralized routing is most appropriate in specific areas with systems providing DWDM (dense wavelength division multiplexing) transmission. The reason is that these DWDM systems contain an OADM (optical add and drop multiplexer) which can be reconfigured inside the starting point and the end point of the communication medium.
Proponents of centralized routing suggest that, since most information such as details on the Shared Risk Link Group (SRLG) and performance metrics does not change frequently (and this information may never be discovered or announced by themselves), it are ideal for residing in a remote environment. central database.
In a centralized model, status information is easily accessible. Therefore, information on dependencies (with regard to routing) between circuits (in order to guarantee diversity) can be managed relatively easily when the terminals are not shared between circuits, which is ideal for a communication model. centralized routing. The centralized model uses global status information.