A class-pinning election scheme for loop-free QoS routing

The main contribution of this paper is the proposal and evaluation of an election approach to provide loop-free class pinning for QoS routing in IP networks. The proposed strategy aims at achieving stability in QoS routing protocols, a situation that is inherently prone to instability. Although the concept of class pinning is inspired in the concept of route pinning, it poses several additional problems, namely, the pinning of paths in hop-by-hop routing and path selection based only on destination address and class of traffic. In hop-by-hop routing, the pinning decision at individual nodes may cause routing loops, since the nodes stop having a coherent view of the state of the network. In view of this problem, the proposed approach addresses class pinning for distributed QoS routing schemes guaranteeing that routing loops does not take place.