26,967 research outputs found
Spare capacity modelling and its applications in survivable iP-over-optical networks
As the interest in IP-over-optical networks are becoming the preferred core network architecture, survivability has emerged as a major concern for network service providers; a result of the potentially huge traffic volumes that will be supported by optical infrastructure. Therefore, implementing recovery strategies is critical. In addition to the traditional recovery schemes based around protection and restoration mechanisms, pre-allocated restoration represents a potential candidate to effect and maintain network resilience under failure conditions. Preallocated restoration technique is particularly interesting because it provides a trade-off in terms of recovery performance and resources between protection and restoration schemes. In this paper, the pre-allocated restoration performance is investigated under single and dual-link failures considering a distributed GMPLSbased IP/WDM mesh network. Two load-based spare capacity optimisation methods are proposed in this paper; Local Spare Capacity Optimisation (LSCO) and Global Spare Capacity Optimisation (GSCO)
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Design of multi-homing architecture for mobile hosts
This thesis was submitted for the degree of Doctor of Philosophy and awarded by Brunel University.This thesis proposes a new multi-homing mobile architecture for future heterogeneous network environment. First, a new multi-homed mobile architecture called Multi Network Switching enabled Mobile IPv6 (MNS-MIP6) is proposed which enables a Mobile Node (MN) having multiple communication paths between itself and its Correspondent Node (CN) to take full advantage of being multi-homed. Multiple communication paths exist because MN, CN, or both are simultaneously attached to multiple access networks. A new sub layer is introduced within IP layer of the host’s protocol stack. A context is established between the MN and the CN. Through this context, additional IP addresses are exchanged between the two. Our MNS-MIP6 architecture allows one communication to smoothly switch from one interface/communication path to another. This switch remains transparent to other layers above IP. Second, to make communication more reliable in multi-homed mobile environments, a new failure detection and recovery mechanism called Mobile Reach ability Protocol (M-REAP) is designed within the proposed MNS-MIP6 architecture. The analysis shows that our new mechanism makes communication more reliable than the existing failure detection and recovery procedures in multi-homed mobile environments. Third, a new network selection mechanism is introduced in the proposed architecture which enables a multi-homed MN to choose the network best suited for particular application traffic. A Policy Engine is defined which takes parameters from iv the available networks, compares them according to application profiles and user preferences, and chooses the best network. The results show that in multi-homed mobile environment, load can be shared among different networks/interfaces through our proposed load sharing mechanism. Fourth, a seamless handover procedure is introduced in the system which enables multi-homed MN to seamlessly roam in a heterogeneous network environment. Layer 2 triggers are defined which assist in handover process. When Signal to Noise Ratio (SNR) on a currently used active interface becomes low, a switch is made to a different active interface. We show through mathematical and simulation analysis that our proposed scheme outperforms the existing popular handover management enhancement scheme in MIPv6 networks namely Fast Handover for MIPv6 (FMIPv6). Finally, a mechanism is introduced to allow legacy hosts to communicate with MNS-MIP6 MNs and gain the benefits of reliability, load sharing and seamless handover. The mechanism involves introducing middle boxes in CN’s network. These boxes are called Proxy-MNS boxes. Context is established between the middle boxes and a multi-homed MN
Will SDN be part of 5G?
For many, this is no longer a valid question and the case is considered
settled with SDN/NFV (Software Defined Networking/Network Function
Virtualization) providing the inevitable innovation enablers solving many
outstanding management issues regarding 5G. However, given the monumental task
of softwarization of radio access network (RAN) while 5G is just around the
corner and some companies have started unveiling their 5G equipment already,
the concern is very realistic that we may only see some point solutions
involving SDN technology instead of a fully SDN-enabled RAN. This survey paper
identifies all important obstacles in the way and looks at the state of the art
of the relevant solutions. This survey is different from the previous surveys
on SDN-based RAN as it focuses on the salient problems and discusses solutions
proposed within and outside SDN literature. Our main focus is on fronthaul,
backward compatibility, supposedly disruptive nature of SDN deployment,
business cases and monetization of SDN related upgrades, latency of general
purpose processors (GPP), and additional security vulnerabilities,
softwarization brings along to the RAN. We have also provided a summary of the
architectural developments in SDN-based RAN landscape as not all work can be
covered under the focused issues. This paper provides a comprehensive survey on
the state of the art of SDN-based RAN and clearly points out the gaps in the
technology.Comment: 33 pages, 10 figure
Segment Routing: a Comprehensive Survey of Research Activities, Standardization Efforts and Implementation Results
Fixed and mobile telecom operators, enterprise network operators and cloud
providers strive to face the challenging demands coming from the evolution of
IP networks (e.g. huge bandwidth requirements, integration of billions of
devices and millions of services in the cloud). Proposed in the early 2010s,
Segment Routing (SR) architecture helps face these challenging demands, and it
is currently being adopted and deployed. SR architecture is based on the
concept of source routing and has interesting scalability properties, as it
dramatically reduces the amount of state information to be configured in the
core nodes to support complex services. SR architecture was first implemented
with the MPLS dataplane and then, quite recently, with the IPv6 dataplane
(SRv6). IPv6 SR architecture (SRv6) has been extended from the simple steering
of packets across nodes to a general network programming approach, making it
very suitable for use cases such as Service Function Chaining and Network
Function Virtualization. In this paper we present a tutorial and a
comprehensive survey on SR technology, analyzing standardization efforts,
patents, research activities and implementation results. We start with an
introduction on the motivations for Segment Routing and an overview of its
evolution and standardization. Then, we provide a tutorial on Segment Routing
technology, with a focus on the novel SRv6 solution. We discuss the
standardization efforts and the patents providing details on the most important
documents and mentioning other ongoing activities. We then thoroughly analyze
research activities according to a taxonomy. We have identified 8 main
categories during our analysis of the current state of play: Monitoring,
Traffic Engineering, Failure Recovery, Centrally Controlled Architectures, Path
Encoding, Network Programming, Performance Evaluation and Miscellaneous...Comment: SUBMITTED TO IEEE COMMUNICATIONS SURVEYS & TUTORIAL
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