Towards Internet QoS Provisioning Based on Generic Distributed QoS Adaptive Routing Engine

Table 1

A comparison between OQRA and PQRA.

Point of view	OQRA	PQRA
Computation	Every time a request initiated.	Precomputes paths from a source to all destinations.
Scalability	Limited.	Large-scale networks.
Suitability	When requests arise infrequently.	When requests arise very frequent.
Pros	Optimal routing during congestion state.	(i) Saves time.; (ii) Better scalability.; (iii) Improved load balancing.
Cons	Puts excessive time on packet processing.	(i) Path oscillation.; (ii) Nonoptimal routing during congestion.; (iii) Resources consumption.; (iv) Complexity.