Optimizing capacity assignment in multiservice MPLS net-works
- Authors: Rassaki, Abdoul , Nel, Andre
- Date: 2017
- Subjects: MPLS , Network capacity assignment , Optimal routing
- Language: English
- Type: Article
- Identifier: http://hdl.handle.net/10210/238052 , uj:24401 , Citation: Rassaki, A. & Nel, A. 2017. Optimizing capacity assignment in multiservice MPLS net-works. South African Computer Journal, 29(1):69–89. DOI: https://doi.org/10.18489/sacj.v29i1.393. , ISSN: 1015-7999 (Print) , ISSN: 2313-7835 (Online)
- Description: Abstract: The general Multiprotocol Label Switch (MPLS) topology optimisation problem is complex and concerns the optimum selection of links, the assignment of capacities to these links and the routing requirements on these links. Ideally, all these are jointly optimised, leading to a minimum cost network which continually meets given objectives on network delay and throughput. In practice, these problems are often dealt with separately and a solution iterated. In this paper, we propose an algorithm that computes the shortest routes, assigns optimal flows to these routes and simultaneously determines optimal link capacities. We take into account the dynamic adaptation of optimal link capacities by considering the same Quality of Service (QoS) measure used in the flow assignment problem in combination with a blocking model for describing call admission controls (CAC) in multiservice broadband telecommunication networks. The main goal is to achieve statistical multiplexing advantages with multiple traffic and QoS classes of connections that share a common trunk present. We offer a mathematical programming model of the problem and proficient solutions which are founded on a Lagrangean relaxation of the problem. Experimental findings on 2-class and 6-class models are reported.
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Incorporating sustainability into IT project management in South Africa
- Authors: Clinning, Grant , Marnewick, Carl
- Date: 2017
- Subjects: Sustainability , Project management , IT project management
- Language: English
- Type: Article
- Identifier: http://hdl.handle.net/10210/238095 , uj:24406 , Citation: Clinning, G. & Marnewick, C. 2017. Incorporating sustainability into IT project management in South Africa. South African Computer Journal 29(1), 1–26. DOI: https://doi.org/10.18489/sacj.v29i1.398. , ISSN: 1015-7999 (Print) , ISSN: 2313-7835 (Online)
- Description: Abstract: The concept of sustainability is becoming more and more important in the face of dwindling resources and increasing demand. Despite this, there are still many industries and disciplines in which sustainability is not actively addressed. The requirement of meeting current and future needs is not an issue from which IT projects are exempt. Ensuring sustainability requires managing sustainability in all activities. The field of IT and sustainability is one in which literature is appearing, but at a slow pace and this leaves many unanswered questions regarding the state of sustainability in IT projects and the commitment of IT project managers to sustainability. In not knowing what the state of sustainability is, potential shortcomings remain unknown and corrective action cannot be taken. Quantitative research was conducted through the use of a survey in the form of a structured questionnaire. This research was cross-sectional as the focus was to assess the state of sustainability at a single point in time. IT project managers were randomly sampled to get an objective view of how committed they were to sustainability. This research made use of a project management sustainability maturity model to measure the extent to which sustainability is incorporated into IT projects. The findings are that IT project managers are not committed to sustainability. While the economic dimension yielded the best results, they were not ideal, and it is in fact the social and environmental dimensions that require the most attention. This lacking commitment to the social and environmental dimensions is not limited to select aspects within each dimension, as each dimension’s aspects are addressed to a similarly poor extent. This research suggests that sustainability needs to become a focus for IT project managers, but for this to happen, they require the relevant project management sustainability knowledge.
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