Multicasting in MPLS networks

The explosive growth of the Internet has generated interests from researchers around the world. New applications of the Internet, such as video, audio and mission-critical applications, challenge researchers to develop more effective ways to deliver these applications to end users. Multicasting, QoS and MPLS emerge as new technologies and are being developed. The integration of MPLS, multicasting and/or QoS is still an open topic. RFC3353, released in August 2002, gives an overview of IP multicast in an MPLS environment. This thesis first presents RFC3353 in brief and then an extension to RFC for multicast aggregation and loop prevention in MPLS networks are discussed. FEC aggregation is proposed where IP header is not affected in the aggregation in MPLS networks. A mechanism to dynamically aggregate multicast traffic in MPLS network is presented in this thesis. Both source specific tree and shared tree are considered as network topologies. Multicast loops may exist in MPLS network during network transition. The multicast loop forming in PIM-SM, PIM-DM and DVMRP is discussed in MPLS networks. The Colored thread and the No thread mechanisms for multicast loop prevention are provided in this thesis. In addition to aggregation and loop prevention, DiffServ multicast traffic merging in MPLS networks is also considered in this thesis. Two multicast traffic merging modes, root-initiated and leaf-initiated, are discussed in such DiffServ-supported MPLS networks. Multicast routing protocols such as PIM-SM PIM-DM and DVMRP are considered here

Multicast traffic aggregation in MPLS-based VPN networks

This article gives an overview of the current practical approaches under study for a scalable implementation of multicast in layer 2 and 3 VPNs over an IP-MPLS multiservice network. These proposals are based on a well-known technique: the aggregation of traffic into shared trees to manage the forwarding state vs. bandwidth saving trade-off. This sort of traffic engineering mechanism requires methods to estimate the resources needed to set up a multicast shared tree for a set of VPNs. The methodology proposed in this article consists of studying the effect of aggregation obtained by random shared tree allocation on a reference model of a representative network scenario.Publicad

Label assignment and failure recovery approaches for IP multicast communication in MPLS networks

Multiprotocol Label Switching (MPLS) is an Internet Engineering Task Force (IETF) framework that provides for the efficient designation, routing, forwarding, and switching of traffic flows through the network. MPLS is widely used for multicast traffic engineering. However, integrating MPLS with IP multicast communication is difficult. This thesis proposes solutions for two problems: label assignment and failure recovery. When a set of multicast flows (sessions) is deployed in an MPLS network, each multicast entry for the sessions consumes an MPLS label. However, MPLS labels are significant resources in MPLS networks, as the 20-bit field of the MPLS header limits the number of available labels. It is advantageous if different multicast sessions can share the same multicast tree in the network and re-use the MPLS label. In the first part of the thesis, we propose two algorithms to do this. The first one is called State Encoding (SE), in which a code is calculated for every tree built in an MPLS network. The second algorithm is called Tree Numbering (TN), where a number represents each tree. If the IP packets of different multicast sessions are delivered over the same tree, all those packets are then classified to the same Forwarding Equivalence Class (FEC) and only one label is used instead of using a number of labels equal to the number of those sessions. The second part of this thesis contributes to this area. To trade off between the large amount of bandwidth required for reserving backup paths in local recovery and the large recovery time taken in global recovery, a new tree division approach is proposed. In this approach, a multicast tree is divided into several domains, where each domain represents a local stand-alone sub-tree of the original one. Two MPLS-based methods are then proposed to set up the backup paths inside the domains. A comparison is made among the local recovery approach, the global recovery approach, a method that sets up the backup paths between the branching points, and the proposed approach. The comparison is based on three metrics: the total backup capacity, the maximum and the average notification times, and the average number of the notification messages that are produced as a result of a failure. In terms of the reserved capacity, the results have shown that our architecture consumes backup capacity close to that consumed by the global recover

Ethernet - a survey on its fields of application

During the last decades, Ethernet progressively became the most widely used local area networking (LAN) technology. Apart from LAN installations, Ethernet became also attractive for many other fields of application, ranging from industry to avionics, telecommunication, and multimedia. The expanded application of this technology is mainly due to its significant assets like reduced cost, backward-compatibility, flexibility, and expandability. However, this new trend raises some problems concerning the services of the protocol and the requirements for each application. Therefore, specific adaptations prove essential to integrate this communication technology in each field of application. Our primary objective is to show how Ethernet has been enhanced to comply with the specific requirements of several application fields, particularly in transport, embedded and multimedia contexts. The paper first describes the common Ethernet LAN technology and highlights its main features. It reviews the most important specific Ethernet versions with respect to each application field’s requirements. Finally, we compare these different fields of application and we particularly focus on the fundamental concepts and the quality of service capabilities of each proposal

Quality of Service over Specific Link Layers: state of the art report

The Integrated Services concept is proposed as an enhancement to the current Internet architecture, to provide a better Quality of Service (QoS) than that provided by the traditional Best-Effort service. The features of the Integrated Services are explained in this report. To support Integrated Services, certain requirements are posed on the underlying link layer. These requirements are studied by the Integrated Services over Specific Link Layers (ISSLL) IETF working group. The status of this ongoing research is reported in this document. To be more specific, the solutions to provide Integrated Services over ATM, IEEE 802 LAN technologies and low-bitrate links are evaluated in detail. The ISSLL working group has not yet studied the requirements, that are posed on the underlying link layer, when this link layer is wireless. Therefore, this state of the art report is extended with an identification of the requirements that are posed on the underlying wireless link, to provide differentiated Quality of Service

On forwarding state control in VPN multicast based on MPLS multipoint LSPs

This work is at: 2012 IEEE 13th International Conference on High Performance Switching and Routing took place June 24-27,2012 in Belgrade, Serbia. Web to event: http://hpsr2012.etf.bg.ac.rs/index.phpThe demand for multicast-capable VPN services, like Virtual Private LAN Service (VPLS), has grown quickly in the last years. In order to save bandwidth, MPLS point-to-multipoint LSPs could be used, but the VPN-specific state information to be handled inside the network may exceed the capacity of core nodes. A well-known solution for this is to aggregate the multicast/broadcast traffic of multiple VPNs into shared p2mp LSP trees. In shared trees, although some bandwidth is wasted because a fraction of the packets are delivered to non-member leaves (either not in the VPN broadcast or multicast group), there is wide working range where a good state vs. bandwidth trade-off is achieved. In this paper we enhance and improve previous works that analyze this trade-off. We propose new techniques for multicast traffic aggregation of VPNs in MPLS-based networks, with the objective of observing the behavior of the aggregation philosophy for different aggregation degrees, which should be very useful for network design and deployment purposes. We assess the aggregation heuristics over different reference networks and VPN geographic distributions. Simulations give a quantitative indication of the relevance of intelligent aggregation, of geographical distribution and group sizes.The work described in this paper was carried out with the support of MEDIANET PRICIT 2009/TIC-1468, from the Community of Madrid; and Fundación Carolina, Spain.Publicad

Software Defined Networks based Smart Grid Communication: A Comprehensive Survey

The current power grid is no longer a feasible solution due to ever-increasing user demand of electricity, old infrastructure, and reliability issues and thus require transformation to a better grid a.k.a., smart grid (SG). The key features that distinguish SG from the conventional electrical power grid are its capability to perform two-way communication, demand side management, and real time pricing. Despite all these advantages that SG will bring, there are certain issues which are specific to SG communication system. For instance, network management of current SG systems is complex, time consuming, and done manually. Moreover, SG communication (SGC) system is built on different vendor specific devices and protocols. Therefore, the current SG systems are not protocol independent, thus leading to interoperability issue. Software defined network (SDN) has been proposed to monitor and manage the communication networks globally. This article serves as a comprehensive survey on SDN-based SGC. In this article, we first discuss taxonomy of advantages of SDNbased SGC.We then discuss SDN-based SGC architectures, along with case studies. Our article provides an in-depth discussion on routing schemes for SDN-based SGC. We also provide detailed survey of security and privacy schemes applied to SDN-based SGC. We furthermore present challenges, open issues, and future research directions related to SDN-based SGC.Comment: Accepte

Recursive SDN for Carrier Networks

Control planes for global carrier networks should be programmable (so that new functionality can be easily introduced) and scalable (so they can handle the numerical scale and geographic scope of these networks). Neither traditional control planes nor new SDN-based control planes meet both of these goals. In this paper, we propose a framework for recursive routing computations that combines the best of SDN (programmability) and traditional networks (scalability through hierarchy) to achieve these two desired properties. Through simulation on graphs of up to 10,000 nodes, we evaluate our design's ability to support a variety of routing and traffic engineering solutions, while incorporating a fast failure recovery mechanism