by Verdi, Fábio Luciano; Carvalho, Cláudio; Magalhães, Maurício F.; Madeira, Edmundo R. M.

This work presents a discussion about policies and architecture to aggregate Internet Protocol/Multiprotocol Label Switching (IP/MPLS) traffics within lightpaths. The scenario is that of IP/MPLS client networks over an optical network. It is well known that aggregating lower traffic flows (e.g., packet-based LSPs—Label Switched Path) within higher traffic flows (e.g., lambda-based LSPs) is considered an effective way to maximize the use of the optical network resources. In this work, the policies are divided into two groups. The first one, which solely considers the class of the flow (High Priority—HP or Low Priority—LP), consists of simple policies meant to aggregate packet-based LSPs within lightpaths. In this group, the policies we have defined intend to reduce the optical network overhead to remove and reroute LP LSPs. The second group presents more sophisticated policies taking into account the possibility of having to deal with further transport faults. In this case, the grooming is better planned and the defined policies tend to reduce the negative impact when a failure is detected in the optical transport network. Our approach has been implemented to validate the policies and the results for each group are showed and discussed.

DOI: 10.1007/s10922-007-9074-9
Online Date: 8/18/2007
Print publication date: 12/1/2008
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by Pinho, Leonardo Bidese; Amorim, Claudio Luis

The growing need for ubiquitous access to video on demand (VoD) applications by large audiences has driven researches to build new scalable VoD systems that can guarantee Quality of Service (QoS) over wireless networks. In this paper, we propose and evaluate a novel system-level design that guarantees QoS by eliminating the service latency for short videos over IEEE 802.11 networks. Furthermore, our VoD system attains scalable performance by employing collocated access points (APs) coupled with an efficient association management of clients to the APs using a generic least-loaded-first heuristic on non-overlapping channels. Simulated results of our VoD system demonstrated that it achieved scalable performance due to its effective use of available bandwidth of the APs while supporting a low blockage rate for short videos up to 360 s. These results suggest that our VoD system can be an attractive solution for several classes of scalable VoD applications that require QoS guarantee such as movie trailers, news, video clips, and commercials.

DOI: 10.1007/s10922-007-9073-x
Online Date: 8/10/2007
Print publication date: 6/1/2008
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