Comparative Analysis of Topology Aggregation Techniques and Approaches for the Scalability of QoS Routing

In this survey, we study and compare topology aggregation techniques pertaining to QoS routing. Aggregation techniques have been an explicit by design or implicit part of many routing protocols, including the currently deployed ones on the Internet due to scalability. Topology Aggregation, defined as those techniques to abstract or summarize the sate information to be exchanged, processed and maintained by network nodes for routing purposes, have not been studied extensively except under a rather limited context. Under the continuing growth of the Internet, scalability issues of routing, and QoS routing in particular, have been gaining more importance than ever. With this in mind, we are surveying the TA techniques from the literature. Many of the techniques of TA, if not in its entirety, seems to be relevant to current and future IP networks, especially when the very active research area of interdomain routing is considered.