Open Shortest Path First

Open Shortest Path First

The link-state routing method known as Open Shortest Path First, or OSPF from here on, employs each router’s own Shortest Path First to determine the optimum path between a source router and a destination router (Pióro et al., 2002, p. 211). The Open Shortest Path First approach is used to accomplish this. As the name implies, Open Shortest Path First use an algorithm to identify the route that will take the least amount of time to go from the router to the destination. To determine the path with the fewest steps, the Dijkstra algorithm is utilized (Nurhaida, Ramayanti, and Nur, 2019). Both an intradomain routing protocol and a means to use link state routing are provided by OSPF. It operates inside a single autonomous system (AS) and belongs to the class of protocols known as internal gateway protocols (IGPs) (Pioro et al., 2002, p. 205). OSPF is a crucial component of the system in an independent system like a local area network (LAN). This protocol separates an AS into regions to facilitate efficient and effective routing management. A set of routers, hosts, and networks that are each a part of a separate system constitutes an area. An AS may be divided into a variety of regions, but it is crucial that every network in every area be linked to every other network.

Every router in the AS has a complete understanding of the AS topology because to the way topology information is transmitted throughout the AS. A modified version of the Dijkstra algorithm is often used to determine how to get from one end of the AS to the other once this picture has been created. As a result, the optimum path from point A to point B to the destination is used to determine the next hop site where information is conveyed (Nwalozie et al., 2012). This ensures that the data travels as quickly as possible to its destination. Each of the five linked routers in the accompanying image is always connected to the one after it in the sequence that provides the quickest connection time. For instance, the route that passes via R4 has the lowest overall cost since it eliminates unnecessary taxes and connects R3 and R5.

Figure 1: A sample OSPF configuration (Adapted from Pióro et al. (2002) and Nwalozie et al. (2012))

The main advantage of a link state routing system like OSPF is its ability to identify routes that meet certain requirements that consider speed, cost, and efficiency. First, because routers have comprehensive topological information, this creates the advantage of thorough analysis and cost reduction. According to Pióro et al. (2002, p. 215), in the OSPF protocol, routers should exchange topological data with the routers that are most nearby. Another advantage is that routes may need to be limited to meet certain service quality standards, and as such, OSPF provides this valuable information for traffic engineering.

However, there are certain advantages linked to OSPF. First, a link state routing system performs noticeably worse when more routers are added to the routing domain (Nwalozie et al., 2012, p. 67). Another notable disadvantage is that the size of the topology updates, their frequency, and the length of time needed to establish end-to-end routes all rise with the number of routers in a network. Because the link state routing protocol cannot scale to the size of the whole Internet (Nurhaida, Ramayanti, and Nur, 2019, p. p.13), IGPs can only route traffic inside their own AS (Mohiuddin, Khan, and Engelbrecht, 2016, p. 599).

In summary, the foundation of OSPF is a well-accepted routing protocol that has been in use for many years. One of the few protocols that is applicable everywhere is OSPF. This is due to the fact that it is one of the few IT industry protocols that is backed by practically all routing vendors and even the open-source ecosystem. Considering these issues, the OSPF is one of the most efficient systems.

Reference List

Mohiuddin, M.A., Khan, S.A. and Engelbrecht, A.P., 2016, ‘Fuzzy particle swarm optimization algorithms for the open shortest path first weight setting problem’, Applied Intelligence, vol. 45, no. 3, pp.598-621.

Nurhaida, I., Ramayanti, D. and Nur, I., 2019, ‘Performance Comparison based on Open Shortest Path First (OSPF) Routing Algorithm for IP Internet Networks’, Commun. Appl. Electron, vol. 7, no. 31, pp.12-25.

Nwalozie, G.C., Okorogu, V.N., Okafor, A.C. and Ume, A.O., 2012, ‘Evaluation and implementation of the open shortest path first (ospf) routing protocol’, International Journal of Emerging Technology and Advanced Engineering, vol. 2, no. 12, pp.64-70.

Pióro, M., Szentesi, Á., Harmatos, J., Jüttner, A., Gajowniczek, P. and Kozdrowski, S., 2002, ‘On open shortest path first related network optimisation problems’, Performance evaluation, vol. 48, no. 1-4, pp.201-223.