Carrier Ethernet Networks Research Articles

Reliability-aware ring protection link selection in Ethernet ring mesh networks

Ring topology is an appropriate solution to be applied on the carrier Ethernet networks due to its high switching speed when one of the links fails. Meanwhile, the ITU-T G.8032 Ethernet ring protection (ERP) recommendation was developed to compete with the switching speed of synchronous digital hierarchy (SDH)/synchronous optical networking (SONET) rings. Nevertheless, ERP has emerged some new optimization issues that the most important of which is to find the ring protection link (RPL). In addition, this issue should also satisfy the network reliability requirements as a key performance parameter. To cope with this problem, in this paper, a new approach is proposed. The main idea behind the proposed approach is to analyze the impact of network links on the overall network reliability. In this regard, the proposed approach consists of five steps: (1) computing the reliability equation for the network through the spanning tree set method, (2) calculating the reliability importance for each link through the Birnbaum importance measure, (3) sorting links based on reliability importance by investigating numerical results, (4) selecting the most appropriate links as RPL per ring by taking into account two modes of working and protection, and finally (5) choosing a ring hierarchy based on the selected RPLs. Performance evaluations demonstrate that the proposed approach provides significant improvement in network reliability compared to the representative approaches.

On control plane algorithms for Carrier Ethernet networks: Unicast, multicast provisioning and control traffic reduction

Carrier Ethernet systems are actively replacing SONET/SDH networks for transport of provider data. After much standardization in both the IEEE and the IETF, Carrier Ethernet has evolved as a rich carrier-class technology. The standards do not focus on specific implementation aspects of providing guaranteed service-oriented features that are intrinsic towards successful replacement of SONET/SDH by Carrier Ethernet solutions. In this paper, we consider the engineering aspects of the Carrier Ethernet software defined control plane for provisioning, managing and maintaining services. Specifically, we propose methods for provisioning guaranteed unicast services considering the underlying network state. The problem is difficult due to the complex nature of admission control coalesced with subjective user requirement that is not easy to rationalize across a network. We also investigate the problem of sub-50ms protection of multicast connections and propose a unique, tractable algorithm within the control plane for enabling carrier-class multicast services. Finally, we focus on overall control traffic reduction schemes. An intuitive merging algorithm is proposed that minimizes control traffic in Carrier Ethernet domains. A simulations study extensively evaluates the proposed techniques.

Models and algorithms for centralized control planes to optimize control traffic overhead

Carrier Ethernet has rapidly advanced to become an important technology in metro transport. However, the overlapping of control plane and data plane in contemporary Carrier Ethernet (CE) networks leads to complex and unmanageable networks. CE networks that use packet technologies ought to be more manageable, scalable and robust. Recently proposed network architecture, Omnipresent Ethernet (OE) recommends that the control and management plane in CE networks be decoupled from the forwarding and routing plane to overcome the problem mentioned earlier. In view of this, we investigate the possibility of a centralized control plane from OE perspective. A centralized control plane is a networking paradigm that abstracts and centralizes the control information of the network from the underlying distributed data-forwarding infrastructure. In this paper, we have focused on engineering and architectural issues related to the design of a centralized control plane for the networks built on OE Networking paradigm. Furthermore, the problem of control traffic overhead in managed networks is analyzed using an appropriate simulation model. A scheme to divide the network into smaller sub-networks is proposed so that the total control traffic is always below some threshold. An Integer Linear Program (ILP) for the controllers' placement in the partitioned network is presented. The ILP attempts to minimize the total control traffic, the total controllers' implementation cost and the overall response time in the network. Since the ILP solves the problem optimally for networks with a limited number of nodes, a heuristic approach is developed and presented for larger and real-time service-provider networks.

An optimization framework for the energy management of carrier ethernet networks with Multiple Spanning Trees

We propose an energy management framework to optimize the energy consumption of networks using the Multiple Spanning Tree Protocol such as Carrier Grade Ethernet networks. The objective is to minimize the energy consumption of nodes and links while considering QoS constraints. The energy management is done through the Multiple Spanning Tree Protocol (MSTP) by choosing from a given set the most appropriate Spanning Trees and the most appropriate edges to operate while respecting the traffic demands. A trade-off framework between energy consumption and network performance is proposed. Results show that it is possible to achieve a good traffic engineering while operating the network closer to the minimum energy value.

An optical performance monitoring method for Carrier Ethernet networks using OAM continuity check messages

A key feature of Carrier Ethernet networks is its operation and management framework. The link state, in this context, is simply determined by the detection (or absence for a given period) of continuity check message (CCM) at the receiver end of a management end point. However, cross-layer information can be inexpensively gained by looking into the loss patterns of these CCM frames, especially when Carrier Ethernet is operating directly over wavelengths (Layer-1) from transparent optical links or networks. This paper experimentally demonstrates a case for optical signal-to-noise and optical signal-to-interference estimation from monitoring standard CCM frame loss frame rate. Moreover, the loss pattern signatures of such physical-layer impairments may give in-depth link state information for fault and performance management as it may give valuable clues about the dominant impairing phenomena.

The evolution of carrier ethernet services-requirements and deployment case studies [next-generation carrier ethernet

Carrier Ethernet is one of the fastest growing areas in the data communication field in recent years. In particular, the combination of MPLS core transport technologies in conjunction with IEEE 802.1ah in aggregation is one of the most interesting recent developments in the Carrier Ethernet evolution. This article provides a brief overview of the Ethernet technologies and requirements from the perspective of the service provider. We use three deployment case studies to illustrate the use of different technologies and discuss network design considerations. We identify the important factors influencing network design decisions and the future work in building Carrier Ethernet networks and services.