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A Session-Based Management Architecture for QoS Assurance to VoIP Applications on Wireless Access Networks
Abstract
The increasing popularity of WLANs-due to the use of license-free radio spectrum with low-cost, easily deployable and high-data-rate wireless services- has encouraged service providers to consider deploying them in high density usage areas, such as public hotspots, to provide complementary broadband access to their networks and services. This article proposes a Session Initiation Protocol based QoS management architecture that aims to provide consistent QoS control for multimedia applications (VoIP, VoD, ...) over wireless access networks. In particular, we will present a generic QoS based management architecture for decentralized management of multimedia applications over wireless access networks, such as WLAN. We will apply our architecture to the management of the WLAN in order to assure QoS (throughput and delay) for the delivered multimedia applications according to users' priorities and providers' objectives. Performance evaluations are discussed to illustrate the feasibility and the efficiency of the proposed architecture through the implementation of a real-world testbed.
... The average call setup In general, IPv4 showed better performance over all scenarios compared with IPv6 for both AODV and OLSR. These results support the research findings in (Boumezzough, Idboufker, andOuahman, 2013 and(Tebbani, Haddadou, andPujolle, 2009) which shows that IPv6-based SIP has longer delays, and size compared with IPv4-based SIP. In addition, the call setup process has the longest delays compared with other SIP call processes over both AODV and OLSR. ...
... The average call setup In general, IPv4 showed better performance over all scenarios compared with IPv6 for both AODV and OLSR. These results support the research findings in (Boumezzough, Idboufker, andOuahman, 2013 and(Tebbani, Haddadou, andPujolle, 2009) which shows that IPv6-based SIP has longer delays, and size compared with IPv4-based SIP. In addition, the call setup process has the longest delays compared with other SIP call processes over both AODV and OLSR. ...
... This is because of the call termination process usage for a simple direct form of SIP messages as represented in Figure 2. In addition, the SIP call termination time has the same values of the SDD performance metric, which makes it simpler to detect the delays and refer it to the termination performance for the benchmarking values. According to (Tebbani, Haddadou, & Pujolle, 2009), the maximum recommended delays for SIP call termination should not exceed 1 second. Thus, based on the SDD values for the investigated scenarios, the termination delays in both the Static and Uniform scenarios are at the accepted level of delays for both AODV and OLSR. ...
In this chapter, analyses for the performance metrics that define the quality of service (QoS) of SIP-based VoIP will be introduced. SIP-based VoIP applications over Direct Mode of Operation (DMO), which behaves in a way similar to Mobile Ad-hoc Network (MANET) systems, have three main performance categories related to the QoS. These categories are the SIP signaling, voice data transmission, and MANET routing. The SIP signaling controls the VoIP calls initiation, termination, and modifications. The major QoS parameters of VoIP that are managed by SIP signaling are the registration intervals, call setup time, and call termination time. These QoS parameters are increased in MANET due to the nodes' mobility that affects the routing calculations and the connectivity status. These necessitate mechanisms to reduce the delays in the MANET environment. The voice packets are transferred over the Real Time Protocol (RTP) which is encapsulated in the unreliable transport protocol using the User Datagram Protocol (UDP).
The evaluation studies need to investigate a determined performance metrics to understand and evaluate the examined scenarios. SIP-based Voice over IP (VoIP) applications over MANET, which behaves in a way similar to Direct Mode of Operation (DMO) in mission Critical Communication Systems, have two main performance categories related to the Quality of Service (QoS). The main performance metrics that are considered for the evaluation processes in this research are the SIP end-to-end Performance metrics as defined by the RFC 6076. The main performance metrics are related to the registration, the call setup, and the call termination processes. In this research study, the SIP performance metrics are based on a single SIP proxy server. For voice data, the QoS evaluation is based on two methods: The Objective method and the Subjective method. The Objective method considers the traffic throughput, end-to-end delays, packet loss, and jitter, while the subjective method considers the Mean Opinion Score (MOS), which is mostly related to the end users' experiences during voice calls.
Several technical issues make commercial and large voice over wireless local area network (VoWLAN) services difficult to provide. The most challenging issue when voice over Internet Protocol (VoIP) services are ran over IEEE 802.11-based WLANs is the bandwidth inefficiency due to the considerable overhead associated with WLAN packet transmission. In this work, we propose a session-based quality-of-service management architecture (SQoSMA) to overcome the low number of VoIP calls in IEEE 802.11 Wireless LANs and the negative effect of new call addition when the WLAN reaches its capacity. The SQoSMA combines data and control planes to detect VoWLAN QoS degradations and performs either an adaptive audio codec switching or a call stopping to fix VoWLAN issues in a differentiated services manner. In addition, our solution deals with user sessions information, by considering user priority (from its agreement) to guarantee a certain level of its multimedia applications. Performance evaluation using a real test-bed shows that call codec change and call stopping techniques can easily assure high-priority calls with acceptable call blocking probability.
We measured the capacity for VoIP traffic in an 802.11b test-bed and compared it with the theoretical capacity and our simulation results. We identified factors that have been commonly overlooked in past studies but affect experiments and simulations. We found that in many papers the capacity for VoIP traffic has been measured via simulations or experiments without considering those factors, showing different capacity in each paper. After these corrections, simulations and experiments yielded a capacity estimate of 15 calls for 64 kb/s CBR VoIP traffic with 20 ms packetization interval and 34 calls to 36 calls for VBR VoIP traffic with 0.39 activity ratio.
Growing demands for the public wireless broadband services will require more capacity than the one provided by IP-based service
providers (ISPs). The increasing popularity of WLANs due to the use of license-free radio spectrum with low-cost, easily deployable,
high-data-rate wireless services, has encouraged service providers to consider their deployment in high density usage areas
such us public hotspots to provide complementary broadband access to their networks and services. In order to provide consistent
QoS control for multimedia applications (VoIP, VoD,...) over hotspots, a Session Initiation Protocol (SIP) based QoS management
architecture is proposed in this article. Performance evaluations are discussed to illustrate the feasibility of the proposed
architecture.
This document defines a general use Differentiated Services (DS) [Blake] Per-Hop-Behavior (PHB) Group called Assured Forwarding (AF). The AF PHB group provides delivery of IP packets in four independently forwarded AF classes. Within each AF class, an IP packet can be assigned one of three different levels of drop precedence. A DS node does not reorder IP packets of the same microflow if they belong to the same AF class.
The definition of PHBs (per-hop forwarding behaviors) is a critical part of the work of the Diffserv Working Group. This document describes a PHB called Expedited Forwarding. We show the generality of this PHB by noting that it can be produced by more than one mechanism and give an example of its use to produce at least one service, a Virtual Leased Line. A recommended codepoint for this PHB is given.
Nowadays, public wireless local area networks (WLANs), commonly called hotspots, are being largely deployed by WISPs (Wireless Internet Service Providers) as a means of offering ubiquitous Internet access to their customers. Although a substantial number of solutions have been proposed to improve security, mobility and quality of service on the wireless area, access network management which is mandatory remains a very significant concern.
This paper describes RSM-WISP, a new management architecture designed for WISPs to facilitate the implementation and management of the services they offer at the access side of the WLAN, and to manage roaming contracts between WISPs. Our architecture is based upon the policy-based management principles as introduced by the IETF, combined with more intelligence at the network edge. RSM-WISP adopts an architecture that is composed of two elements: a WISP management center (MC) that deploys policies and monitors all the WLANs, and a programmable access router (CPE) located in each WLAN. The CPE ensures service enforcement, service differentiation (access to different service levels) and guarantee, user access management, and dynamic WLAN adaptation according to the user's SLA (service level agreement). It also permits automatic service updates according to the user's requirements. Concerning roaming management, this is achieved on the CPE through multiple service provider support capabilities. This approach provides WISPs with a simple, flexible and scalable solution that allows easy service deployment and management at the access. This management architecture has been implemented, tested and validated on the 6WINDGate routers. Copyright
In this paper, we contribute on the service-driven management of quality of service and user access in wireless corporate networks. We propose a Service-Level Agreement (SLA) oriented nomadism management architecture with a top-down vision starting by the specification of company objectives and going down to device-level configurations. We define an algorithm for the automatic translation of application-level quality assurance parameters into network-level configuration parameters. A prototype implementation of our solution to the SLA-driven enterprise nomadism management is presented along with preliminary results on the self-adaptive capabilities of our QoS mapping algorithm.
In this paper, we present experimental studies on the throughput of IEEE 802.11b wireless networks for UDP and VoIP traffic. Our experiments show that the maximum data throughput of a single station sending out UDP traffic is 6.1 Mbps. The maximum number of VoIP calls in a single cell of an IEEE 802.11b network is six if the ITU G711a-Law codec is used with 10 milliseconds of audio per RTP packet. The experiments also show that the effective available bandwidth in the wireless network is reduced by ongoing VoIP connections. Specifically, for the above codec settings, each VoIP connection reduces the bandwidth available for data traffic by 900 kbps.
Wireless local-area networks (WLANs) based on the IEEE 802.11 technology have been widely adopted for private use over the past few years. However, several issues remain concerns for large-scale deployment in corporate environments. Enforcing security and quality-of-service (QoS) has become a fundamental challenge to managing IEEE 802.11-based enterprise networks. In order to provide corporate networks with a global management solution, we have designed a service-oriented management system that enables user-centric service provisioning, while enforcing security and QoS requirements. As enterprises may be comprised of a number of distinct networks, we have extended our system to support the roaming of users between different enterprise sites. In this paper, we describe the design, implementation, and performance evaluation of our solution.
Today, the policy-based management approach is recognized as an efficient solution to simplify the complex task of managing and controlling networks. To this end, the IETF has introduced a reference framework to build PBM systems. However, this framework only addresses the provisioning of relatively long validity period services based on pre-defined service level agreements. Furthermore, very little work addresses the scalability properties of the instantiation of this framework in a real network. This work aims to extend the IETF PBM framework in order to support dynamic provisioning of short term services (end system signaling) as well as an instantiation scheme that is scalable (distributed provisioning of edge routers). This instantiation scheme is based on the distribution of the provisioning process while keeping centralized only the parts that involve critical resources, that is, the bandwidth brokerage. The performance properties of the proposed scheme are then demonstrated throughout both extensive experimentation and a short analytical study. The results of this work are intended to be used as a guideline to help network operators to design scalable PBM system in order to offer to their customers services with QoS assurance in an on-demand basis.
JAIN envisions the creation of a number of Java APIs that abstract
the details of networks and protocol implementations, and allow for the
development of portable applications. The JAIN Protocol Experts Group
(PEG) will focus on developing Java APIs for protocols used in
telephony, INs, wireless networks, and the Internet. The PEG is
organized into an SS7 subgroup and an IP subgroup. The article provides
an introduction to PEG. It next describes the JAIN SS7 APIs. It then
describes the JAIN IP APIs. The article also explains how JAIN SS7 and
IP APIs can be leveraged for the converged SS7-IP networks of the future
and describes the JAIN PEG roadmap
Network Grade of Service Parameters and Target Values for Circuit-Switched Services in Evolving ISDN
- I Union
Linux Advanced Routing and Traffic Control HOWTO, A very hands-on approach to iproute2, traffic shaping and a bit of netfilter
- B Hubert