Study of signaling effects on Dynamic Traffic Grooming in IP/MPLS over WDM network

Signaling is essential in a practical network for connection establishments. Previous works on Dynamic Traffic Grooming (DTG) did not consider the signaling and related information update. The performance is poor when we incorporate the signaling requirement in previous DTG algorithms. This shows that the effect of signaling cannot be ignored in a practical network. In this paper, we discuss the effect of signaling on DTG, and propose a new technique called DTG-PRL to handle the DTG problem. In DTG-PRL, we divide the DTG into two steps: (1) pre-reserve some lightpaths based on statistical traffic observations and (2) dynamically groom the traffic based on the established virtual topology. We have developed an ILP formulation and a heuristic algorithm for the purpose. The simulation results show that the DTG-PRL outperforms previous DTG algorithms in IP Bandwidth Blocking Probability, Network Resource Utilization, Connection Setup Time and Control Message Efficiency. This demonstrates the usefulness of DTG-PRL in practical networks.     

Routing and wavelength assignment in optical WDM networks with maximum quantity of edge disjoint paths

In the present paper, routing and wavelength assignment (RWA) in optical WDM networks is discussed. Previous techniques based on the combination of integer linear programming based lpsolver and graph coloring are complex and require extensive use of heuristics such as rounding heuristic which makes them slow and sometimes practically not reasonable. Another method employs the greedy approach in graph theory for obtaining available edge disjoint paths. Even though it is fast, it produces a solution for any connection request which is far from the optimal utilization of wavelengths. We propose a novel algorithm, which is based on the maximum flow to have the maximum quantity of edge disjoint paths. Here, we compare the offered method with previous edge disjoint paths algorithms applied to the RWA. Comprehensive computer simulation shows that the proposed method outperforms previous ones significantly in terms of running time. Furthermore, the new method shows compatible or better performance comparing to others in number of wavelengths used.The earlier version was published in ICCS 2004, Poland (Krakow). This research was supported by the Ministry of Information and Communication, Korea under the Information Technology Research Center support program supervised by the Institute of Information Technology Assessment, IITA-2005-(C1090-0501-0019).     

Providing differentiated services for multi-class traffic in IP/MPLS over WDM networks

Providing differentiated services in IP/MPLS over WDM networks has attracted a lot of recent attention. This article extends the Path Inflation Control (PIC) policy recently proposed by us to provide differentiated services in IP/MPLS over WDM networks with traffic grooming. Three different algorithms are considered for provisioning differentiated services. The simulation results show that, with two of the three algorithms, the network cannot only provide differentiated services when the traffic load is high but also gives significantly lower blocking for the lower priority class traffic and for the overall traffic at low traffic loads.

AMROEBA: Computational astrophysics modeling enabled by dynamic lambda switching

Many data and compute intensive Grid applications, such as computational astrophysics, may be able to benefit from networking supported by dynamically provisioned lightpaths. To date, the majority of high performance distributed environments have been based on traditional routed packet networks, provisioned as external services rather than as integrated components within those environments. Because this approach often cannot provide high performance capabilities required by these applications, an alternative distributed infrastructure architecture is being designed based on dynamic lightpaths, supported by optical networks. These designs implement communication services and infrastructure as integral components of distributed infrastructure. The resultant environments resemble large scale specialized instruments. Presented here is one such architecture, implemented on a wide-area, optical Grid test bed, featuring a closely integrated dedicated lightpath mesh. The test bed was used to conduct a series of experiments to explore its potential for supporting adaptive mesh refinement (AMR) astrophysics simulations. While preliminary, the results of these experiments indicate that this architecture may provide the deterministic capabilities required by a wide range of high performance distributed services and applications, especially for computational science.     

Signalling end-to-end optical services over multi-domain networks

This paper proposes a new UCLP (User-Controlled LightPath) architecture that offers end-to-end optical services provisioning in a multi-domain network. It also shows the experimental results of our UCLP software tool implemented on the Canarie optical network testbed. This work is motivated by the growing need for end-to-end lightpaths to support high volume data transferring applications such as GridFTP (GRID File Transfer Protocol) and SAN (Storage Area Networks) over multi-domain networks. The main problems encountred while provisioning end-to-end optical service in a multi-domain network are investigated and a review of the different interdomain signalling approaches is provided in comparison with our user-controlled lightpath provisioning approach. Various interdomain signalling approaches are discussed and compared to justify the necessity of signalling methods at the application level for long-duration applications.