940 research outputs found
Endpoint-transparent Multipath Transport with Software-defined Networks
Multipath forwarding consists of using multiple paths simultaneously to
transport data over the network. While most such techniques require endpoint
modifications, we investigate how multipath forwarding can be done inside the
network, transparently to endpoint hosts. With such a network-centric approach,
packet reordering becomes a critical issue as it may cause critical performance
degradation.
We present a Software Defined Network architecture which automatically sets
up multipath forwarding, including solutions for reordering and performance
improvement, both at the sending side through multipath scheduling algorithms,
and the receiver side, by resequencing out-of-order packets in a dedicated
in-network buffer.
We implemented a prototype with commonly available technology and evaluated
it in both emulated and real networks. Our results show consistent throughput
improvements, thanks to the use of aggregated path capacity. We give
comparisons to Multipath TCP, where we show our approach can achieve a similar
performance while offering the advantage of endpoint transparency
Congestion aware multipath routing: performance improvements in core networks
In this paper the improved Congestion Aware Multipath Routing algorithm is analysed in terms of Core network throughput and longer paths contribution. The algorithm discovers unused network resources and dynamically adapts to the actual traffic load and available resources displacement. Several simulation scenarios have been benchmarked in order to verify algorithm in typical Internet Service Provider cases. Simulation scenarios in this paper are focused on verifying functionality in dense core networks. For this purpose, tests were performed on TeraStream based network ĂąâŹâ the Deutsche Telekom Group design concept. Simulation results have proven better performance and resource utilization of the proposed algorithm than traditional Bellman-Ford based algorithms and equal cost multipath approaches
Early Experiences in Traffic Engineering Exploiting Path Diversity: A Practical Approach
Recent literature has proved that stable dynamic routing algorithms have
solid theoretical foundation that makes them suitable to be implemented in a
real protocol, and used in practice in many different operational network
contexts. Such algorithms inherit much of the properties of congestion
controllers implementing one of the possible combination of AQM/ECN schemes at
nodes and flow control at sources. In this paper we propose a linear program
formulation of the multi-commodity flow problem with congestion control, under
max-min fairness, comprising demands with or without exogenous peak rates. Our
evaluations of the gain, using path diversity, in scenarios as intra-domain
traffic engineering and wireless mesh networks encourages real implementations,
especially in presence of hot spots demands and non uniform traffic matrices.
We propose a flow aware perspective of the subject by using a natural
multi-path extension to current congestion controllers and show its performance
with respect to current proposals. Since flow aware architectures exploiting
path diversity are feasible, scalable, robust and nearly optimal in presence of
flows with exogenous peak rates, we claim that our solution rethinked in the
context of realistic traffic assumptions performs as better as an optimal
approach with all the additional benefits of the flow aware paradigm
QoS-based multipath routing for the Internet
The new generation of network services is being developed for incorporation in communication infrastructure. These services, generally called Quality of Services (QoS), should accommodate data file, video, and audio applications. The different performance requirements of these applications necessitate a re-examination of the main architectural components of today\u27s networks, which were designed to support traditional data applications. Routing, which determines the sequence of network nodes a packet traverses between source and destination, is one such component. Here, we examine the potential routing problems in future Internet and discuss the advantages of class-based multi-path routing methods. The result is a new approach to routing in packet-switched networks, which is called Two-level Class-based Multipath routing with Prediction (TCMP). In TCMP, we compute multiple paths between each source and destination based on link propagation delay and bottleneck bandwidth. A leaky bucket is adopted in each router to monitor the bottleneck bandwidth on equal paths during the network\u27s stable period, and to guide its traffic forwarDing The TCMP can avoid frequent flooding of routing information in a dynamic routing method; therefore, it can be applied to large network topologies
Multipath routing and QoS provisioning in mobile ad hoc networks
PhDA Mobile Ad Hoc Networks (MANET) is a collection of mobile nodes that can
communicate with each other using multihop wireless links without utilizing any
fixed based-station infrastructure and centralized management. Each mobile node
in the network acts as both a host generating flows or being destination of flows
and a router forwarding flows directed to other nodes.
Future applications of MANETs are expected to be based on all-IP
architecture and be capable of carrying multitude real-time multimedia
applications such as voice and video as well as data. It is very necessary for
MANETs to have an efficient routing and quality of service (QoS) mechanism to
support diverse applications.
This thesis proposes an on-demand Node-Disjoint Multipath Routing protocol
(NDMR) with low broadcast redundancy. Multipath routing allows the
establishment of multiple paths between a single source and single destination
node. It is also beneficial to avoid traffic congestion and frequent link breaks in
communication because of the mobility of nodes. The important components of
the protocol, such as path accumulation, decreasing routing overhead and
selecting node-disjoint paths, are explained. Because the new protocol
significantly reduces the total number of Route Request packets, this results in an
increased delivery ratio, smaller end-to-end delays for data packets, lower control
overhead and fewer collisions of packets.
Although NDMR provides node-disjoint multipath routing with low route
overhead in MANETs, it is only a best-effort routing approach, which is not
enough to support QoS. DiffServ is a standard approach for a more scalable way
to achieve QoS in any IP network and could potentially be used to provide QoS
in MANETs because it minimises the need for signalling. However, one of the
biggest drawbacks of DiffServ is that the QoS provisioning is separate from the
routing process. This thesis presents a Multipath QoS Routing protocol for
iv
supporting DiffServ (MQRD), which combines the advantages of NDMR and
DiffServ. The protocol can classify network traffic into different priority levels
and apply priority scheduling and queuing management mechanisms to obtain
QoS guarantees
Abstract â Wireless Multimedia Sensor Networks
(WMSN) can handle different traffic classes of multimedia content (video, audio streams and still images) as well as scalar data over the network. Use of general and efficient routing protocols for WMSN is of crucial significance. Similar to other traditional networks, in WMSN a noticeable proportion of energy is consumed due to communications. Many routing protocols have been proposed for WMSN. The design of more efficient protocols in terms of energy awareness, video packet scheduling and QoS in terms of checkpoint arrangement still remains a challenge. This paper proposes the actuation of sensor on demand basis and routing protocol based on cost function which efficiently utilizes the network resources such as the intermediate nodes energy and load. Cost function is introduced to improve the route selection and control congestion. Simulation results, using the NS-2 simulator show that the proposed protocol prolongs the network lifetime, increase the reliability and decrease the network load
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