IP Multimedia Subsystem Network Research Articles

Investigating indirect impacts of TCP connection on IMS network

The IP Multimedia Subsystem (IMS) is recently expected to have the major architecture framework to be involved in the Next Generation Network. IMS works to bridge the multimedia communication among variety of applications over Internet. IMS bears its multimedia signals and stream through different means of transport protocols; TCP, UDP, and SCTP. TCP is a connection-oriented protocol that provides reliable data delivery and congestion control. To setup connection with TCP, IMS entities requires extra operations to complete, that operation process called (worker process) costs the multimedia server extra overload and delay. This paper investigates the indirect impacts of TCP connection that resulted from the Call Session Control Function (CSCF) servers when it deal with video communication. Two parameters are evaluated in experiment which are CPU usage and response time with two different scenarios. The experimental shows that outbound scenario performs better than the inbound scenario due to the extra operations required to setup new TCP connection for inbound

Comparative analysis of fuzzy logic and AHP method for QoS management in LTE network: IMS case study

In recent years, increasing demand for IP Multimedia Subsystem (IMS) services raised several problems and challenges concerning the Quality of Service (QoS) management. Thus, each operator has to make its network more efficient for ensuring an acceptable level of QoS. The 3rd Generation Partnership Project (3GPP) offers several scenarios for providing services, but without any control or correction for QoS degradation. However, reaching the QoS satisfaction becomes more difficult and complicated due to changes in preferences and mobility of customers. In this regard, a new approach of multi-level criticality for managing the customer's request for guaranteeing a QoS at any time is proposed. To achieve this goal, several criteria were used for decision-making to offer the appropriate QoS level to the customers according to their levels of criticality. In this paper, a comparative analysis of the fuzzy logic and Analytic Hierarchy Process (AHP) method for multi-criteria has been presented to evaluate QoS and criticality levels for QoS management in the IMS network. The simulation results describe the comparison between these two methods to illustrate their feasibility for QoS management to find who gives better results in the aspect of the chance value of QoS and criticality levels.

Service Broker-Based Architecture Using Multi-Criteria Decision Making for Service Level Agreement

With the on-going trends of the telecom services, the number of service providers with similar functionalities is undergoing a rapid growth. The customers face the difficulty to decide which service provider can satisfy their needs and full their requirements. Negotiating contracts between involved parts, and hiding heterogeneity in the distributed network environment has been challenging for telecom operators and service providers. Different languages exist to describe the Service Level Agreement (SLA), which is a contract between a service provider and a customer. However, since each service provider expresses his SLA in his own way, it disrupts the customer's choice of the best service provider, and leads to a bad contract management. In this respect, we propose a novel architecture for service selection, and SLA management between different stakeholders in our network architecture. The idea is to set up a smart broker where we implemented a Multi-Criteria Decision Making (MCDM) method to maximize utility function so that the customer can choose services with required QoS performances. We also came up with the idea of settling a negotiation model for the SLA, and a context based SLA contract ontology in IP Multimedia Subsystem (IMS) network is also proposed to provide users with a clear model to express their requirements and preferences. Moreover, we used the New Generation Operations Systems and Software (NGOSS) Framework to model and analyze networks and services actions. To better understand the relationship and the projection of NGOSS Framework and IMS platform, we introduce an SLA management and monitoring architecture in IMS network.

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.

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.

Providing IPTV in the IMS network

Providing IPTV in the IMS network is increasingly a problem solved today. All households are gradually passing through innovation and slowly every equipment becomes the so-called intelligent or smart and can be connected to a private or public network where it can be monitored, configured, diagnosed and then repaired.. This same upgrading takes place in television, and its current output is in the form of IPTV (Internet Protocol Television) provided in the IP Multimedia Subsystem Network, a new generation network that provides both audio and video data. IMS has originated in 1999 for the 3GPP standard in the 5th edition when switching from a 2G network to a 3G network. It has supported the older GSM and GPRS networks, but also a new UMTS network. In the sixth edition, it also has began to work on WLAN networks, more voice-oriented, or speech recognition services. This paper focuses on the provision of IPTV (Internet Protocol Television) in the IMS (IP Multimedia Subsystem) network. The aim of our paper is to design IPTV services in the IMS network, define the IMS architecture and the IMS network components such as HSS (Home Subscriber Server), various types of CSCF (Call State Control Function), describe the functionality and services provided by IMS and IPTV and, finally, compare the quality of the IPTV service provided by our network and by network of selected operator.

Analyse of Measurement Based Admission Control Methods in IMS Networks and Simulation Principle

This paper deals with the quality of service in IP Multimedia Subsystem networks. The evaluation of Quality o Service (QoS) is done through admission control methods. We analyse various methods, which are based on the traffic measurement. The approach that can be applied in finding the suitable admission control method while considering selected QoS parameters is described. Different important QoS parameters can be defined, however we decided to focus on the loss parameter. In our simulations we have used Simple Sum method. Based on the simulation results, we have used new algorithm. The main difference is that it uses the mechanism of time window for achieving more accurate traffic estimate. Algorithm Measured Sum with implementation of time window T has better ability to predict the traffic fluctuation. Compared to the Simple Sum algorithm it achieves lower link utilisation, but also lower level of loss ratio.

Security Enhancement Architectural Model for IMS based Networks

Objectives: The IP Multimedia Subsystem (IMS) is an architectural framework for delivering protocol-based services that enables an easy deployment of new rich multimedia services mixing voice and data. In fact, the IMS is vulnerable to several malicious uses that can be conducted by its users. We propose in this paper, a security enhancement architectural model to monitor the system and build a rapid and normal functioning retrieval after failing. Methods/Statistical Analysis: The weakness of the IMS network topology structure makes it a target for both normal cellular threats and IP-related threats. We propose a model that consists of dividing a complex set of end-of-end (IMS-based) network security related features into separate architectural components, layers and tiers in order to divide the system and to be more precise in the problems’ detection phase. Findings: Using the proposed approach, an effective evaluation study is investigated. The simulated network adopting our model showed an excellent behavior. The quality metric measuring call quality showed some excellent results. In other words, the adoption of the proposed model does not affect the normal frame delays, packet arrival durations and packet loss rates. The results showed how our proposed model is lightweight and effective in handling security issues. Application/Improvements: This paper fulfills a huge need of handling security using an effective lightweight architectural model adopting the proposed approach. Our methodology ensures designing a secure, flexible and easily monitored network with a rapid location of the affected areas and effective security supervision.

A Load-Balanced Call Admission Controller for IMS Cloud Computing

Network functions virtualization provides opportunities to design, deploy, and manage networking services. It utilizes cloud computing virtualization services that run on high-volume servers, switches, and storage hardware to virtualize network functions. Virtualization techniques can be used in IP multimedia subsystem (IMS) cloud computing to develop different networking functions (e.g., load balancing and call admission control). IMS network signaling happens through session initiation protocol (SIP). An open issue is the control of overload that occurs when an SIP server lacks sufficient CPU and memory resources to process all messages. This paper proposes a virtual load balanced call admission controller (VLB-CAC) for the cloud-hosted SIP servers. VLB-CAC determines the optimal call admission rates and signaling paths for admitted calls along with the optimal allocation of CPU and memory resources of the SIP servers. This optimal solution is derived through a new linear programming model. This model requires some critical information of SIP servers as input. Further, VLB-CAC is equipped with an autoscaler to overcome resource limitations. The proposed scheme is implemented in smart applications on virtual infrastructure (SAVI) which serves as a virtual testbed. An assessment of the numerical and experimental results demonstrates the efficiency of the proposed work.

Admission Control Methods in IMS Networks

The article deals with solving the problem of ensuring Quality of Service (QoS) in IP Multimedia Subsystem (IMS) networks. Admission Control methods (AC) are used to prevent network congestion and the decrease of QoS. The main function of AC is to maximize utilization of network resources and to ensure the level of QoS. Four methods were chosen for comparison. These methods are described in the main part of the article. The last part deals with simulations of these methods in the software MATLAB.

Design of a Novel Architecture Signaling Network to Provide Internet Multimedia Subsystem Services through Aeronautical Passenger Communication

This article describes a novel architecture signaling network so that an IP Multimedia Subsystem (IMS) user, flying in an aircraft, be able to register with his IMS network of origin and have access to personal services and multimedia, through a Wide-Band Code Division Multiple Access (W-CDMA) link. The proposed architecture integrates the Session Initialization Protocol (SIP), the Network Mobility Basic Support (NEMO BS) protocol and the Mobile Internet Protocol (MIPv6) to enable the usage of IMS services by passenger on board an aircraft, as a type of Aeronautical Passenger Communication (APC) services. In this novel architecture, NEMO and MIPv6 protocols are responsible for the mobility management of smartphones and user notebook and the SIP protocol is responsible for the register and the management of sessions of an IMS user. This novel architecture enables an Air Communication Service Provider (ACSP) be able to supply to an on-board passenger (The IMS user) some APC services through an Universal Mobile Telecommunication System (UMTS). The simulation results indicate the accuracy of the proposed architecture into aeronautical scenarios.

Performance Analysis of IMS Network: the Proposal of new Algorithms for S-CSCF Assignment

This article is focused on the proposal of three load balancing methods which can be used for a selection of S-CSCF (Serving-Call Session Control Server) server in IP Multimedia Subsystem (IMS) during the registration procedures of subscribers. All presented methods are implemented and evaluated for various inter-arrival and service times in the mathematical model based on queueing theory. In this article, two methods based on performance parameters (such as utilizations, etc.) and one method based on number of registered subscribers to each of available S-CSCF server are described. The main advantage of third method is that all related information is obtained from traffic analysis through I-CSCF (Interrogating-CSCF) node. Also, the designed methods are compared with other selection algorithms presented in previous research works by others researchers (Hwang et col., Cho et col. or Tirana et col.). The article shows that the implemented methods can optimize the service latency of whole IMS network.

PTT Service Interworking Between IMS Based Networks and P2P Overlay Networks

The demand for multimedia streaming services is increasing rapidly. To meet this demand, there has been much research and many practical developments for providing multimedia services. A push-to-talk (PTT) service is one of the multimedia streaming services that have been deployed not only over IP multimedia subsystem (IMS) but also in peer-to-peer (P2P) overlay networks. The benefit of PTT has been demonstrated in the literature. However, the need for using PTT service in communication can be arbitrary among users, regardless what kind of PTT services they use. This demand does not support current PTT systems, so an expansion of PTT services still be limited. Moreover, the combination of PTT services in IMS and P2P networks will help operators to provide more scalable PTT services. Therefore, in this paper, we proposed a model to support PTT service interworking between IMS and P2P overlay networks. We also introduced our system design and some interworking service scenarios. We confirmed our architecture through implementation and testing.

A Parsing Mode based Method for Malformed SIP Messages Testing for IMS Network

IMS(IP Multimedia Subsystem) network uses SIP (Session Initiation Protocol) as its core control protocol. The defensive ability of the malformed SIP message is particularly important for IMS network security. In this paper, we propose a malformed SIP generation method based on SIP parsing mode and the associated attack testing method. Based on SIP parsing mode of functional entities in IMS, we generate effective malformed SIP messages, which then be used to perform attacking test to IMS functional entities by establishing different session models, so as to evaluate the defensive ability of these entities and provide recommendations for improving the security of the IMS network. We generated a set of malformed SIP messages through this method and apply them to the attacking test of the well-known IMS testbed OpenIMSCore under different session models. The testing finds new vulnerabilities in OpenIMSCore, which shows that our method of malformed SIP messages generation is effective.

Mobile-to-Mobile Multimedia Service Provisioning in the IMS Using REST-Based Mobile Services

 Abstract—With the merging of IP and TelCo networks, Mobile-to-Mobile (M2M) social networks are to be unfolded as an ultimate telecom business in the near future. By M2M, both service provider and service client are aimed to be mobile based. Hence considering mobile devices to be resource constrained and mobile networks as low-bandwidth networks, provisioning high-profile multimedia services is not somewhat straight forward. The Quality of Service (QoS) has always been a great concern in this scenario. Additionally in M2M service networks, the direct IP accessibility of mobile devices is a bottleneck in seamless communication. The cellular operators typically block every incoming http access to subscribers devices inside and outside the network due to huge traffic load and security reasons. The paper addresses the issues faced in M2M service networks and presents a solution based on the IP Multimedia Subsystem (IMS). Similar to SIP Application Servers (AS) in the IMS network, the concept of Mobile Application Servers (Mob-AS) is introduced in order to host and execute multimedia services from a mobile device. A comprehensive design of Mob-AS is presented based on the existing REST interfaced synchronous and asynchronous mobile server framework.

Design of Transparent Distributed IMS Network: Security Challenges Risk and Signaling Analysis

The IP Multimedia subsystem (IMS) based on SIP as mechanism signalling and interfaces with other servers using OSA (Open Service Access) and CAMEL (Customized Applications for Mobile network Enhanced Logic).Is responsible for the interconnection of IP packets with other network, IMS support data communication services, voice, video, messaging and web-based technologies. In this work we present a distributed design of architecture that turns up some challenges of transparent mobility on the secured IMS architecture. We introduced the architecture with clustering database HSS and automatic storage of data files that give a secure access to database. This paper gives an overview of classification of security in IMS network and we show delay analysis comparison in signalling interworking with and without securing Gateway (SEG) in the registration of any UE in access network based IMS. We show that there is a tradeoff between the level of increasing system security and the potential delay incurred by mobility in Access Network .we conclude that this architecture is suitable for operators and services providers for the new business models delivering ,the services based IMS Everywhere, anytime and with any terminals.

A Method Based on BP Neural Network to Detect SIP DOS Flooding Attack

In order to detect the SIP flooding attacks in IMS (IP Multimedia Subsystem) network, the paper proposes a flooding attack detection method based on BP neural network, and analyses causes of SIP flooding attack, and thus determine the BP the input of the neural network characteristics. The simulation results show that this method has better detection performance.

IMS-Based Centralized Service Continuity

The IP Multimedia Subsystem (IMS) has been selected as a telecommunication industrial standard for the signal processing in the heterogeneous access networks. It is also brought up to handle the mobility management. However, the mobility of the user equipment (UE) may disrupt or even intermittently disconnect an ongoing real-time session, which heavily affects the satisfaction of the users. Therefore, how to reduce the service disruption time gets more and more important. This paper first proposes a centralized service continuity scheme, abbreviated as CSC, in IMS-based networks. The CSC treats handover as a service in the IMS network. Its architecture and operation are based on service invocation. The service continuity procedure is performed by an application server called CSC AS. The CSC AS can carry out the third-party call control for fast session re-establishment by initiating two INVITE requests concurrently. In addition, a variant of the CSC, denoted by CSC*, is derived by adopting the E-IMS AKA with one-pass authentication for achieving the acceleration of IMS registration during the handover. Analytical results show that both schemes could shorten the handover latency significantly, as compared with the standard IMS-based service continuity.

Conferencing Service Interworking in Peer-to-Peer and IMS Networks

The growth of Internet technologies and the widespread use of mobile devices have been paving the way for the increasing use of conferencing services. Two types of systems have been designed to provide conferencing services: 1) a conferencing system using session control over a peer-to-peer (P2P) network and 2) an IP Multimedia Subsystem (IMS) conferencing system. The IMS conferencing system was developed to adapt to a server-based centralized system, whereas the benefits of the P2P operational model in providing such conference services are widely acknowledged. However, each system provides conferencing services only to its own users. Therefore, in this paper, we propose an interworking model to support multimedia conferencing service between the P2P environment and IMS networks. We also introduce protocol architecture and some service scenarios. To verify this system model and the design architecture, we perform an actual implementation and show experienced test results.

A Secure Architecture for Nomadic User in IMS Network

The IP multimedia subsystem (IMS) is a basis for a significant new architecture which offers network operators the opportunity to expand their services, by integrating voice and multimedia communications and delivering them into new environments with new purposes. Basically, the IMS is an overlay network on top of IP layer that uses Session Initiation Protocol (SIP) as the primary signaling mechanism. SIP works at the application layer in IP networks. It is thus faced to not only the IP-networks security issues, but also to new issues which are related to the SIP protocol directly. Consequently, using IMS bears several new security challenges. This paper presents the most relevant SIP-related security vulnerabilities and threats, and the implementation and simulation test bed to experiment two versions of the SIP Asterisk software to emphasize these threats. The different security mechanisms that can be deployed to overcome the SIP security issues while putting emphasis the most important ones are discussed. Afterwards, the authors propose adaptable solutions to the SIP threats already identified for a specific service (access information from anywhere) in IMS context. Finally, conclusions are drawn and some perspectives are introduced to improve the security of multimedia applications.