IP Multimedia Subsystem Research Articles

Dual server based security system for multimedia Services in Next Generation Networks

Next Generation Networks (NGN) provide multimedia services to a large set of users by maintaining concurrent sessions for multimedia services using IP multimedia sub-system (IMS). SIP protocol are used for building, keeping and detaching session with clients. The main problem is that intruders can launch SIP flooding attacks that cause a bottleneck at IMS entities. In this paper, we have presented a Dual Server based Intrusion Detection and Prevention System (DS-IDPS) to guard against INVITE flooding attack. We have proposed two-level security for VoLTE environment by involving two servers titled helper and main servers to handle spoofing and attack detection respectively. We have defined three thresholds at main server by utilizing CUSUM algorithm to generate alarms by detecting intrusion. By attaching DS-IDPS at the middle of client and server, our system filters every request. We have developed a test bed using OpenIMS to develop IMS entities and launch attacks by malicious nodes and detect the intrusion in the system. It reduces CPU load and memory stack from P--CSCF. Results prove that DS-IDPS produces lesser false alarms and detect more number of malicious or bogus requests. Our proposed approach dominates as compared to preliminaries in terms of memory utilization, response time, malicious requests recognition ratios and CPU load consumption.

Statistical Assessment of IP Multimedia Subsystem in a Softwarized Environment: A Queueing Networks Approach

The Next Generation 5G Networks can greatly benefit from the synergy between virtualization paradigms, such as the Network Function Virtualization (NFV), and service provisioning platforms such as the IP Multimedia Subsystem (IMS). The NFV concept is evolving towards a lightweight solution based on containers that, by contrast to classic virtual machines, do not carry a whole operating system and result in more efficient and scalable deployments. On the other hand, IMS has become an integral part of the 5G core network, for instance, to provide advanced services like Voice over LTE (VoLTE). In this paper we combine these virtualization and service provisioning concepts, deriving a containerized IMS infrastructure, dubbed cIMS, providing its assessment through statistical characterization and experimental measurements. Specifically, we: i) model cIMS through the queueing networks methodology to characterize the utilization of virtual resources under constrained conditions; ii) draw an extended version of the Pollaczek-Khinchin formula, which is useful to deal with bulk arrivals; iii) afford an optimization problem focused at maximizing the whole cIMS performance in the presence of capacity constraints, thus providing new means for the service provider to manage service level agreements (SLAs); $iv)$ evaluate a range of cIMS scenarios, considering different queuing disciplines including also multiple job classes. An experimental testbed based on the open source platform Clearwater has been deployed to derive some realistic values of key parameters (e.g. arrival and service times).

Predicting failures in multi-tier distributed systems

Many applications are implemented as multi-tier software systems, and are executed on distributed infrastructures, like cloud infrastructures, to benefit from the cost reduction that derives from dynamically allocating resources on-demand. In these systems, failures are becoming the norm rather than the exception, and predicting their occurrence, as well as locating the responsible faults, are essential enablers of preventive and corrective actions that can mitigate the impact of failures, and significantly improve the dependability of the systems. Current failure prediction approaches suffer either from false positives or limited accuracy, and do not produce enough information to effectively locate the responsible faults.In this paper, we present PreMiSE, a lightweight and precise approach to predict failures and locate the corresponding faults in multi-tier distributed systems. PreMiSE blends anomaly-based and signature-based techniques to identify multi-tier failures that impact on performance indicators, with high precision and low false positive rate. The experimental results that we obtained on a Cloud-based IP Multimedia Subsystem indicate that PreMiSE can indeed predict and locate possible failure occurrences with high precision and low overhead.

Theoretical Approach to Optimization of Home Subscriber Server in IP Multimedia Subsystem

Our paper deals with structure of Home Subscriber Server in IP Multimedia Subsystem and mathematical models for optimizing this database. The aim of our work is choose and verify proper models for dimensioning of traffic in the HSS. In this paper we describe the Markov M/M/1/K and M/M/m/K models and Erlang C formula. Simulations are graphically interpreted in MATLAB and results are discussed.

Distributed intrusion detection scheme for next generation networks

IP Multimedia Subsystem (IMS) is a next generation network that provides the hypermedia services as data, voice and video to users. Due to high level requirements for IMS services, new kinds of network attacks are endlessly emerging. Thus, it is of paramount importance to protect the networks from attacks. Consequently, the Intrusion Detection Systems (IDS) are quickly becoming a popular requirement in building a network security infrastructure. Securing service and signalization is a vital feature in the IMS network. Signaling is generally based on Session Initiation Protocol (SIP) which offers numerous challenges regarding security which causes issues in IMS network. This work presents a study of SIP protocol and discovers the critical security vulnerabilities in the course of registration phase. We focused on DDoS attacks on IMS server using SIP particularly with REGISTER message and proposed a scheme based on multi agent systems for intrusion detection which takes the advantage of the distributed paradigm to implement an efficient distributed system, as well as the integration of existing techniques, i.e., the well-known IDS SNORT.

End-to-middle-to-end solution for IMS media plane security

IP multimedia subsystem (IMS) is becoming the prevailing candidate for managing future mobile multimedia communications, including critical communications such as public safety, emergency professionals and corporate networks. IMS security and privacy has gained much attention in the few last years. The review of recent IMS security activities stresses the inclusion of intermediate nodes in the media path of secured communications as an open issue. This paper presents an end-to-middle-to-end solution which enables the usage of IMS media plane elements such as recorders, transcoders and novel cross-ciphering functions in a secure way. The proposed solution, which is fully compliant with IMS, includes the network architecture, the signaling plane for session signaling and key management, and the media-plane security characteristics. Experimental results demonstrate that the proposed solution can provide media interoperability (both transcoding and cross-ciphering) with a cost of 17 % overhead to a standard IMS call setup in the signaling plane.

Overload control for virtual network functions under CPU contention

In this paper, we analyze the problem of overloads caused by physical CPU contention in cloud infrastructures, from the perspective of time-critical applications (such as Virtual Network Functions) running at guest level. We show that guest-level overload control solutions to counteract traffic spikes (e.g., traffic throttling) are counterproductive against overloads caused by CPU contention. We then propose a general guest-level solution to protect applications from overloads also in the case of CPU contention. We reproduced the phenomena on a IP Multimedia Subsystem (IMS) testbed based on OpenStack on top of KVM. The results show that the approach can dynamically adapt the service throughput to the actual system capacity in both cases of traffic spikes and CPU contention, by guaranteeing at the same time the IMS latency requirements. • Resource contention is a common cause of overload in virtualized infrastructures. • CPU contention causes side effects on the QoS of time-critical applications. • Guest OS CPU metrics are often misinterpreted when dealing with CPU contention. • NFV Load throttling solutions can misbehave in the case of physical CPU contention. • Avoiding idle CPU time preemption helps to protect systems from contention effects.

QoS Based IPTV over LTE-WLAN Heterogeneous Networks

Heterogeneous networks required IP Multimedia Subsystem (IMS) technologies to perform their control signaling and improve their communication services. However, the highest IPTV-QoS cannot be performed using IMS only as it cannot differentiate between IPTV video components. In this paper, we implement our IPTV-flow label technique in LTE-WLAN heterogeneous systems that used to improve QoS by providing IPTV sub traffic priority according to the network administrator policy. The proposed architecture has been implemented and analyzed using Opnet Modeler 17.5 software. The produced results demonstrate that IPTV users receive high definition video data with a variation in quantity in conformity with data priority by using Opnet 17.5 software.

An IMS-Based Advanced Handoff Scheme for Wi-Fi/LTE Integrated Framework

Integrating heterogeneous access technologies to provide users with always best connected services is one of the primary objectives of fourth-generation wireless technologies. The major research issue in an integrated framework is to enable mobile users with fast and smooth connectivity while switching between heterogeneous access technologies. In this paper, an integration framework for Wireless Fidelity/Long-Term Evolution access technologies is presented with IP Multimedia Subsystem for service provisioning. An inter-domain handoff scheme called SIP advanced handoff is proposed which utilizes improved Session Initiation Protocol (SIP) and Mobile IPv6 with a multilayer approach which enables fast and smooth connectivity with minimized handoff latency and improved throughput. A simulation is carried out using NS2, and the performance characteristics are studied. The measured handoff performance metrics reveal that successful video session handoffs are achieved with acceptable quality of services levels and further that the proposed scheme shows better performance than the conventional scheme.

Analysis of Operator XL Axiata’s Readiness on IP Based Voice Interconnection to Support Voice over LTE Implementation

Indonesian cellular operators have deployed Long Term Evolution (LTE) technology to improve data services to users. To provide voice service, LTE operators introduce Voice over LTE (VoLTE) with better quality than Voice over IP (VoIP) service because it has low latency and larger capacity. VoLTE technology with an IP Multimedia Subsystem (IMS) platform is an IP based technology that will work best when interconnecting between IP telecommunication operators using IP protocols such as SIP or SIP-I session protocol. Currently, interconnection of telecommunication operators in Indonesia is sti ll time-based division multiplexing (TDM) interconnection. This research will discuss mobile operator infrastructure readiness to migrate interconnection from TDM-based network to IP and will calculate bandwidth requirement for IP interconnection network. With data from XL Axiata operator it was found that IP interconnection caused a decrease in bandwidth requirements of XL Axiata operator compared when using TDM-based interconnects. The value of bandwidth requirement reduction is strongly influenced by the type of codec used. It appears that the G.723 codec provides significant bandwidth reduction but has a low mean opinion score (MOS).

Anlisis QoS Open IMS Core berbasis Network Function Virtualization pada Protokol TCP

IP Multimedia Subsystem (IMS) is an NGN technology to convergence support of wireline and wireless networks with QoS guarantees. Therefore IMS is widely used by telecommunications operators. Increasing customers make operators overwhelmed by having to replace or add new devices to increase IMS capacity, which is less profitable for operators on the operational costs. The concept of Network Function Virtualization (NFV) is solve the problem. The concept changed of hardware-dedicated to software-dedicated in a virtual environment allows the NFV to be more flexible in increasing device capacity and can reduce dependence on hardware purchases. In this research IMS implemented using Open IMS Core and NFV infrastructure software using OpenStack. analysis based on QoS file transfer services and web servers by measuring parameters throughput, delay, jitter, and packet loss. Based on the measurement of QoS parameters obtained by traffic load of 0 Mbps, 10 Mbps, 20 Mbps, 30Mbps. The throughput average values on file transfer service are 0.2906 Mbit / s and 16.4366 Mbit / s on web server services. The delay average value on file transfer service is 25.5077 ms and 0.7708 ms on the web server service. The resulting jitter value is <1 ms. Percentage of packet loss is < 1%.

EVALUATION OF SERVICES QUALITY IN IMS

The main stages of the historical development of telecommunication networks are shown. It is noted that today the most common concepts are NGN (Next Generation Network), supporting the functionality of Triple-Play Services (triple services – voice, video and data transmission), as well as IMS (IP Multimedia Subsystem), which combines cellular technology and landline communications. They are able to provide a wide range of services: basic, additional, intelligent. In addition, IMS is able to provide mobile services. The IMS architecture layers are presented – transport layer, control layer; layer of service and application servers. Particular attention is paid to the layer of service and application servers. Based on the analysis of ITU recommendations, the main telecommunication services quality indexes are determined, namely, the time of service provision, the length of the queue that the service request falls into to wait for service on the server, and the probability of refusing to provide services. Based on the proposed mathematical models of the NGN intelligent superstructure, analytical expressions are presented for calculating the quality indexes of intelligent services in NGN for one type of service and for K types of services, taking into account the self-similarity of traffic, and without taking into account. To evaluate the quality of services in IMS, it is proposed to use the approaches of queuing theory and tensor analysis. Tensor analysis offers a mathematical apparatus for transforming coordinate systems, considering IMS as a set of geometric objects whose projections are different in different coordinate systems, but the physical properties of the objects themselves do not change. Expressions are proposed that make it possible to calculate the following QoS indexes in IMS: average queue length, average residence time of an application in the system for all types of services in IMS. It is considered that the incoming traffic is the simplest. Further development of the work is to take into account the self-similar nature of traffic, which is created by the flow of requests for services that come to IMS, as well as the limitations of the server buffer, which will allow a more accurate assessment of the quality of services in IMS.

Security evaluation management over LTE critical infrastructures networks: IMS case study

The security of telecommunications infrastructures is a major issue for satisfied it in terms of confidentiality, integrity, availability and in terms of quality of services (QoS) and it is difficult to guarantee the availability of these critical infrastructures (CIs) 24 hours a day. They present the vulnerabilities and a failure in one CI can impact to another CI to cause service disruptions. In this purpose, we propose a new approach of multi-level criticality to better assess and monitor CIs and their interdependencies in order to predict possible risks for increasing security. This paper proposes CI security modelling for trust components and interdependencies based on multi-levels of criticality, which are added to the security of IP multimedia subsystem (IMS) components to reduce its impacts and improve its resilience in order to prioritise risks according to several levels of criticality. The proposed approach is based on Totel model and implicative interdependency model (IIM).

Scalability and Performance Analysis of SIP based Multimedia Services over Mission Critical Communication Systems

Various studies have suggested enhancing the performance of large-scale systems, such as mission critical communication systems (MCCSs). However, few have modelled and evaluated the performance of such systems in a way that targets overall system performance in real time. Moreover, it is not enough to define the Key Performance Indicators (KPIs) for a system without using them for system performance measurement and performance evaluation. The Session Initiation Protocol (SIP) and IP Multimedia Subsystem (IMS) both have a set of KPIs, such as the registration process delay, that can be used to measure and thus optimize overall system performance. This article articulates different options for system simulation and evaluation. The registration process affects performance and reflects the overall system performance. The article shows how the registration process is delayed and how the overall system scalability are negatively impacted by system overload.

NFV-Based Architecture for the Interworking Between WebRTC and IMS

The emerging paradigm of network function virtualization (NFV) technology promises an efficient solution for optimized service deployment in the cloud computing environment thanks to its ability to dynamically add or remove virtual resources when there is a change in workload. Nevertheless, telecom providers are still facing a challenging issue in efficiently adopting NFV to deploy Web real-time communication (WebRTC) service on top of IP multimedia subsystem (IMS). Providing WebRTC service increases the inherent complexity of the IMS system in terms of the number of service nodes as virtual network functions (VNFs) and the way they interact, both of which play significant roles in the problem of optimally allocating resources. This paper proposes a virtualized interworking system between IMS and WebRTC called NFV-based interworking architecture, and describes the mechanism for VNFs to exchange messages with each other. We present an analytic system model considering the constraints of resources, quality of service (QoS), and service costs. A real-time Markov approximation-based resource allocation algorithm (RIDRA) is then designed allowing a provisioned resource at service nodes to be reconfigured in time to meet performance requirements. The proposed solution is evaluated on the large scale by simulation and on the small scale by our developed testbed. Experimental results reveal that our algorithm effectively responds to fluctuating service demands with a service cost reduced by 19% via efficiently allocating virtual resources while maintaining QoS requirement.

An IP Multimedia Subsystem Services Proxy Gateway Based on a JAVA Dynamic Module System

By virtue of the rapid development of the Information and Communication Technology (ICT), people have owned various devices connected to the Internet to enjoy various emerging application services, such as multimedia related services. IP Multimedia Subsystem (IMS) is the integration platform for multimedia application services and provides a rich feature set of converged services in the Next Generation Network (NGN). IMS services are accessed by a user anytime and anywhere through his/her personal self IMS device, e.g., mobile device, equipped with a Universal Subscriber Identity Module (USIM) card. People have owned various devices connected to the Internet at homes or offices. However, some devices can not access IMS services without USIM cards embedded, which is called non-IMS devices. People wish that more devices without USIM cards embedded should be connected to the Internet on which IMS services are accessed in addition to the mobile devices equipped with USIM cards. Accordingly, we propose an Open Service Gateway Initiative (OSGi)-based IMS service gateway, in which OSGi technology is the dynamic module system for JAVA. The proposed gateway is authorized by a personal self IMS device such that IMS services are accessed by non-IMS devices, in this paper. Moreover, these non-IMS devices rely on different networks to access technologies and network protocols and the IMS service gateway proposed here adopts the OSGi framework for no problem of integration.

Refactoring Network Functions Modules to Reduce Latencies and Improve Fault Tolerance in NFV

Network functions virtualization (NFV) allows service providers to deliver new services to their customers more quickly by adopting software-centric network functions implementation over commercial, off-the-shelf hardwares. This NFV-based software-centric approach cannot use dedicated mechanisms implemented over custom built boxes to reduce latencies and tolerate faults. We present a case study of IP multimedia subsystem (IMS), which is the most complex NFV instance, requires extremely low end-to-end latency (40 msec), and demands system availability as high as five nines. Through an empirical study, we discover that highly modular IMS network functions implementation over virtualized platform: 1) incurs latencies and 2) does not tolerate faults. NFV-based IMS modules incur high latencies by creating a feedback loop among each other while executing delay sensitive data-plane traffic. These IMS modules are also susceptible to failure, causing the control-plane to terminate the application session while keeping the data-plane to forward data packets. To address these issues, we propose to refactor network function modules. We reduce latencies by pipelining the IMS modules, and recover failed modules by reconfiguring their neighboring modules. We build our system prototype of open source IMS over OpenStack platform. Our results show that our scheme reduces latencies and failure recovery time up to $12\times $ and $10\times $ , respectively, when compared with the state-of-the-art virtualized IMS implementation.

Optimising Differentiated Services Strategies under IMS

The evolving standards of mobile communications, the wide variety of services they offer and the rapid growth of the Internet have made a merger of the two network technologies inevitable. One of the most prominent platforms that has been developed to facilitate this is the IP Multimedia Subsystem (IMS) concept. Many mobile communications standards integrate IMS as the main core network architecture and Quality of Service (QoS) is the main concern for customer satisfaction. A major approach to optimisation of QoS is the Differentiated Services scheme, and a simulation study of implementations of this is presented. The study covered an IMS core network architecture modelled with discrete-event network simulator software, with a Differentiated Services QoS scheme run over it with differing bearer traffic scenarios. Implications for core network architectures are discussed.

OTT VoIP over LTE vs. VoLTE End-to-End QoS using OPNET

Long Term Evolution (LTE) is a totally IP based cellular network, that only supports packet switching (PS) function, previous cellular networks, such as 2G and 3G, were basically designed to carry voice calls through circuit switching (CS) service, then data service was supported through techniques that basically encapsulated data inside the voice-call connections. In LTE there are many alternatives for offering voice services over LTE to ensure the service continuity over celluar networks, these alternatives include Voice over LTE (VoLTE), also include Over the Top Voice over IP (OTT VoIP) one of the proposed alternatives for voice service over LTE, which is the lowest in cost and complexity. The objective of this paper is, to investigate the quality of the low cost OTT VoIP voice service, as an alternative to VoLTE, especially for those Mobile Network Operators (MNOs), who aren’t ready to deploy the highly complex and costly IP Multimedia Subsystem (IMS) infrastructure of VoLTE . Performance evaluation for OTT VoIP over LTE, compared with VoLTE is provided, from the most important QoS parameters point of view, in different scenarios with different number of users assuming congested and non-congested network states, the analysis for all these scenarios are based on simulations using OPNET 17.5 simulation tool, the results provide a performance template for MNOs who doesn’t want to deploy IMS and doesn’t have legacy 2G/3G networks.

Behavior study of SIP on IP multimedia subsystem architecture MPLS as transport layer

IP Multimedia Subsystem “IMS” is the modular architecture that provides users with reliable access to multimedia services (voice, video conferencing, interactive services, etc.). However, quality of service and security are one of the main concerns of operators when it comes to multimedia services. The Multi-Protocol Label Switching (MPLS) protocol ensures these two basic needs. IMS is primarily based on the Session Initiation Protocol (SIP) for (i) routing, (ii) establishing, (iii) modifying, and (iv) closing a multimedia session. The SIP protocol represents the most influential protocol in the IMS architecture. The objective of this paper is to evaluate the performance of the SIP protocols in an IMS architecture with the MPLS protocol as the transport layer protocol. The evaluation will focus on: (I) the impact of the number of connections on the duration of SIP session establishment and (Ii) the impact of the number of users on the performances of IMS services (VOIP and Videoconferencing).