Yashar Fazili

Hybrid Energy-aware and SLA-based Routing Mechanism over Optical Networks☆

Abstract Satisfying customers’ traffic engineering connection requests is one of the biggest challenges of todays service providers. However, routing mechanisms which only consider service level specifications as the path selection criteria may not be aware of energy consumption and Co2 emission rate of the routed paths. This can generate huge Co2 emissions and consume energy inefficiently. This paper introduces a hybrid green SLA-based routing approach to lower the Co2 emission rate while it provides the most available routes between any pair of source and destination. A new hybrid path cost function is also proposed in which Co2 emission rate, path length, and path availability are taken into account as the route selection process criteria. As a result of employing the new energy-aware routing algorithm together with the novel path cost function, paths with the minimum Co2 emission and less assigned network resources will be selected while service level agreement requirements are still met.

Adaptive Green Routing Mechanism over Optical Networks

This paper is an extension to the previous work that introduced the hybrid energy-aware and service level agreement (SLA) based routing mechanism over optical networks. This paper introduces an adaptive SLA-based routing approach to lower the Co2 emission rate while it provides the most available routes between any pair of source and destination. The paper benefits from the hybrid path cost function presented in the previous work in which Co2 emission rate, path length, and path availability are taken into account as the route selection process criteria. The mechanism proposed in this paper re-routes established optical paths using an adaptive green routing algorithm after the nodes in the network are informed of any changes on the emission factors of the links. As a result of employing the new energy-aware routing algorithm together with the novel path cost function, paths with the minimum Co2 emission and less assigned network resources will be selected. The algorithm presented in this paper keeps Co2 emission at the lowest level with maintaining an adaptive re-routing mechanism over the duration of connections while service level agreement requirements are still met.

Dynamic Inter-domain Negotiation for Green Algorithms in Optical Networks☆

Abstract This paper presents a dynamic inter-domain negotiation mechanism over green optical networks. The proposed propagation mechanism disseminates the source types of energies to all nodes while it advertises a proposed path attribute called minimum path emission. The paper shows how the dynamic negotiation protocol along with the proposed traffic engineering metric improves the performance of green algorithms. This mechanism helps service providers to control the network Co2 emission level in WDM networks and keep the network as green as possible.

The effect of adopting green SLA on key parameters of optical WDM networks

This paper presents green service level agreement (GSLA) awareness for the hybrid and traditional routing mechanisms by proposing a mathematical model for the amount of route greenness, and proposing two algorithms for the adoption of GSLA. The effect of the adoption of GSLA on a network that on average has green energy available for longer duration of a day is modeled by defining a one-step two-by-two Markov matrix and representing the transformation through a state machine. This work also examines a re-provisioning algorithm to deal with the effect of re-provisioning of the established lightpaths in case of a change in the topology of a network. To study the effect of adopting GSLA, two Scenarios with different arrival rates of connections and four performance parameters such as average emission per lambda, average connection length, GSLA satisfaction and success rate are defined and analyzed over NSFnet. Results reveal that adopting the GSLA by routing mechanisms decreases the resource efficiency with both light and heavy traffic in return for less reduction in emission as compared to green and hybrid routing mechanisms.

Analysis on the Effect of Adopting Green SLA on Optical WDM Networks

Abstract This paper analyzes the effect of Green Service Level Agreement (GSLA) on resource efficiency and emission reduction of wavelength-division multiplex (WDM) optical networks governed by Generalized Multi-Protocol Label Switching (GMPLS). Green routing mechanisms may use more resources in serving equal number of connection requests in optical networks, which makes them less favorable for Internet and infrastructure providers. This work shows that the usage of green and hybrid routing mechanism is in fact more resource efficient than using traditional non-green routing methods by simply choosing the greenest route. The amount of greenness of routes in optical networks is requested through GSLA mandating service providers to provide routes for connection requests that are being powered ON by at least certain amount of green energy such as solar energy.

Multi SLA Aware Green Provisioning Mechanism for WDM Networks

Abstract This paper introduces a simple mechanism which attempts to reduce the energy consumption and corresponding Co2 Greenhouse Gas (GHG). This mechanism couples an emission reduction method with multiple service provider Service Level Agreements (SLAs) to ensure an acceptable Service Level Satisfaction (SLS). This purpose is accomplished by formulating and solving a multi-constrained optimization problem. The results show emission reduction with acceptable SLS. This mechanism can be used in different control environments, such as Software Defined Networks (SDN) or Generalized Multi-Protocol Label Switching (GMPLS).

Greenness Link State Advertisement Extension for WDM Networks

Abstract This paper introduces a new Link State Advertisement (LSA) for a new link characteristic to be used with Constrained Open Shortest Path (CSPF) routing mechanism. The new LSA is to be exploited for building a topology database based on realistic energy and Co2 emission data about each link and the sections of the network. The energy-aware CSPF mechanism can use this topology database to incorporate energy and emission information in routing data traffic form greener sections of network.

Inter-domain Hybrid Metric as SLS Dissemination Mechanism in Green Optical Networks.

Abstract This paper introduces the dissemination of Hybrid cost calculated for each route in Emission Aware and SLA Based Routing Mechanism as path attribute for purpose of inter-domain routing operation. This paper then compares the performance of the routing mechanism using this method against performance of the routing methods using other types of transmitted metrics such as energy code.

Table Driven Hybrid Energy-aware and SLA-based Routing Mechanism over Optical Networks

Abstract This paper introduces an improvement for Hybrid Energy Aware and SLA Based (EASB) routing mechanism enabled for GMPLS networks. The performance of EASB is enhanced significantly by consulting a routing table populated in advance, instead of route calculation for each connection request. The table is “looked up” to determine the route that has the minimum hybrid cost for the given source-destination pair of the connection request. As a result a node with lower compute capability can be used to server the equal amount of connection requests while maintaining emission and resource efficiency.

Forward Looking Emission Aware and SLA based Routing Mechanism

Abstract This paper introduces an SLA-based routing mechanism to lower the Co 2 emission rate of the optical networks governed by GMPLS. This approach provides the most available routes between any pair of source and destination nodes using a routing table populated in advance, using the combination of weather forecasting information and energy resource maps supplied to the control plane of GMPLS optical networks.