SIP messages delay analysis in heterogeneous network

IP Multimedia Subsystem (IMS) network peering is a key enabler that will help accelerate deployment of next-generation IMS-based networks. Today's early deployments of dispersed IMS networks require public switched telephone network (PSTN)/public land mobile network (PLMN) bridges for network interconnection between IMS islands. The PSTN/PLMN bridging arrangement is inefficient, however, in that it results in unnecessary settlements for the carriers. It further impedes the implementation of rich multimedia and Voice over IP (VoIP)-related services that require end-to-end Internet Protocol (IP) connectivity. Last, it perpetuates the reliance on the existing PSTN/PLMN network for voice calls among subscribers served by different IMS-based carriers. This paper analyzes in detail the IMS peering challenges from the perspective of Session Initiation Protocol (SIP) signaling peering. It discusses issues related to the routing of SIP messages, and addressing, address resolution, and discovery of peering points for IMS signaling peering. It further establishes that a new routing algorithm is needed that will allow signaling peering points to dynamically discover the “best” transit network among others for reaching a destination. In closing, it presents a high-level IMS signaling routing process that includes, among other benefits, support for number portability as a key function for inter-carrier IMS peering.

All-IP wireless networking infrastructures, such as those based on Internet Multimedia Subsystem (IMS), are becoming increasingly important due to the variety of applications they support, which include Voice over IP (VoIP) and real-time streaming multimedia. These applications are imposing specific requirements on network and wireless systems in terms of session (call) setup time. Call setup time is particularly important for interactive applications, such as gaming and push-totalk communication, where the user experience of time that takes to start or join a session directly translates in user perception of QoS. In this paper, we present a comprehensive approach to analyze the call set up time in IMS systems deploying Session Initiation Protocol (SIP) for signaling and CDMA2000 Evolution Data Only Rev. A (EV-DO-A) standard for wireless link transmission. Our model is based on practical assumptions for the system design parameters, including radio link delays, IMS processing and signaling properties. We derive important numerical results and present methods to improve the call setup time. Finally, we discuss directions for further research.

In the signaling plane of an IMS (IP Multimedia Subsystem) network, the interrogating Call/Session Control Function (I-CSCF) is required to choose the serving CSCF (S-CSCF) for user requests arriving at the proxy CSCFs (P-CSCF). This requires S-CSCF selection in such a way that the response time is minimized. However, in an overloaded situation, the P-CSCF entry points for arriving requests must balance between rejecting new requests and having an acceptable response time from S-CSCF for those that are allowed to enter. In this setting, we consider a number of controls for congestion avoidance that work in conjunction with S-CSCF selection in an IMS Network. For balancing between rejection of requests and the response time, we also propose a composite metric. Through our studies on grid topologies, we observe that one of the avoidance algorithms, the bang-bang control, generally shows to be the most promising toward striking a good balance between rejection of requests and the response time.

In mobile networks, hand over refers to the process of transferring a communication from one cell to another considering the power levels of the signal and latency values. In LTE (Long Term Evolution), base stations are able to perform handover by using the X2 interconnected interface. To provide voice call over LTE (VoLTE) using a packet-switch network, an IMS (IP Multimedia Subsystem) network is also deployed. The main contribution of this work is the analysis of power consumption of a Device under Test (DuT) during intra-cell handover procedures for a VoLTE call. Empirical results show the energy consumption along the different stages of the communication between the DuT and the base station. In addition, jitter and throughput values are assessed during the intra-cell handover process. The highest power consumption was obtained during the hand over procedures and as expected, jitter values increase too. Empirical results provide key points for energy efficiency improvements.

IMS (IP multimedia subsystem) is a main trend of development NGN. The base of IMS is an Internet Protocol which initially did not provide support for quality of service. However, for the transmission of multimedia streams is necessary to ensure a given level of quality of service (QoS). Therefore, IMS QoS estimation is a necessary task but a high complexity of network topologies and a large number of information flows makes it difficult to solve this problem. In IMS network, QoS support is provided by the interaction of systems of IMS on control and application planes. This interaction based on the signalling message exchange that also has delay. This paper presents the results to create a nodal tensor model of IMS network for delay analysis. In this model, the main systems of the IMS network such as CSCF (Call Session Control Function), HSS (Home Subscriber Server) etc. are represented as a single-server queuing systems. Model is formed in accordance to the postulates of the tensor analysis of networks. Moreover, proposed model allow estimating the delay time as for the individual routes, and for the whole network. Research of the model allowed determining such distribution of traffic that resulted to the minimum value of the delay that in turn leads to increased QoS of information flows in an IMS network.

Users and enterprise needs will drive multimedia service evolution for both mobile and fixed operators. IMS (IP Multimedia Subsystem) is a recognized standard of 3GPP group. IMS is well integrated with existing voice and data networks, while adopting many of their key characteristics. The SIP servers are the key part of the IMS structure. They are the main components responsible for processing and routing messages. With communication networks getting more and more present in our daily activities, network outages or significant degradations of the quality of service (QoS) become less and less tolerable. Our research works on improvement of the QoS in IMS networks. It is base in the one hand modeling traffic and on the other hand dimensioning traffic. These performance optimizations are essentially dedicated to the traffic of input and output flows at SIP servers. We build OpenSource IMS platform under UBUNTU Linux distribution.

Distributed intrusion detection scheme for next generation networks

The IP Multimedia Subsystem (IMS) has been considered to be exclusive to big players of the telecommunication world. Session Initiation Protocol (SIP) has been standardized by IETF and solutions based on it have been in the market at least for a decade. It is also an essential part of the IMS, as it is the control protocol of IMS. Recent development of the Linux platform and the Open source IMS system has lead to a situation where the IMS is also an affordable solution for smaller telecommunication companies. The obvious question has been whether the level of performance with Open source IMS is really suitable for business usage. ETSI-TISPAN has unified IMS performance measurements by defining a common framework which to follow in measurements. The paper presents comparisons between IMS and SIP based networks in call and messaging performance. the Open IMS solution by the Fraunhover Focus Institute is compared with the OpenSIPS, an open source SIP server. The number of users in our measurements was chosen to be 100 000, a large enough number to be considered as a suitable number of users for small or moderate business usage needs. Our study shows that both of the systems are able to handle this many users and, in the case of OpenSIPS, with a clear margin. It was also discovered that both systems are reliable and are suitable for small and moderate business usage.

To determine the potential signaling traffic reductions, the session establishment procedures are investigated. The investigation shows that, the S-CSCF (Serving Call Session Control Function) is the major bottleneck in IMS (IP Multimedia Subsystem) and the existing 3GPP (the 3rd Generation Partnership Project) Service Triggering Algorithm (3GPP STA) increases largely the end to end session setup delay. To reduce the session setup delay and improve the system performance, a new Group based Service Triggering Algorithm (GSTA) is proposed. And then the modeling of 3GPP STA and GSTA are presented. Theoretical analysis and simulation results show that, GSTA can efficiently reduce the signaling traffic load of the S-CSCF, increase the throughput of the system and considerably reduce the session setup delay, improve IMS network quality of service.

This chapter describes the support for IP based multimedia services on Third Generation (3G) wireless cellular networks. While earlier cellular networks offered only basic IP connectivity on a best-effort basis, 3G networks provide explicit support for real time multimedia services with guaranteed Quality of Service (QoS). As a result, they can offer traditional voice telephony, rich telephony services and multimedia streaming over IP, both inside a 3G network and in conjunction with external networks such as the Internet, the Public Switched Telephone Network (PSTN) and the Integrated Services Digital Network (ISDN). In fact, 3G networks will deploy for the first time in a large scale technologies such as IP version 6 (IPv6) and policy based IP QoS, spearheading the introduction of such technologies into the Internet. The two most important aspects of 3G networks with respect to IP based multimedia services are the IP Multimedia Subsystem (IMS) and the Multimedia Broadcast / Multicast Service (MBMS). The IMS enables complex IP based multimedia sessions to be created with guaranteed QoS for each media component. Example applications include voice telephony and video conferencing. The IMS interoperates with both traditional telephony services and external IP based multimedia services. The MBMS provides native IP broadcast and multicast support in 3G networks, allowing high bandwidth services to be economically offered to multiple users. Example applications include video streaming via multicast and location based services via broadcast. The MBMS interoperates directly with IP multicasting. While both the IMS and the MBMS are IP based, their standardization is proceeding independently. It is however clear that their combination would allow numerous new services to be provided. The outline of this chapter is as follows. In Section II we give an overview of cellular networks and their evolution, while in Section III we describe in detail a specific 3G network, the Universal Mobile Telecommunications System (UMTS). Section IV presents an introductory description of the features and services provided by the IMS and the MBMS. In Section V we provide the details of the IMS, including service architecture, session setup and control and interworking issues. Section VI describes the MBMS in the same manner as for the IMS. Finally, Section VII discusses the QoS issues for IP based multimedia services, describing the overall QoS concept, the policy based QoS control scheme and its application to IMS sessions. At the end of the chapter, Tables II and III list the acronyms used. An extensive UMTS vocabulary is provided in [1].

The IP Multimedia Subsystem (IMS) in all-IP based next generation communication environment can offer network/service providers various multimedia services (e.g.,voice, audio, video and data etc). The IMS is worthy of notice in that it is possible to make wired/wireless convergence and quick service development. The IMS needs an efficient Session Initiation Protocol (SIP)-based routing among Call Session Control Functions (CSCF) in charge of call and session processing. In this paper, we propose a dynamic routing algorithm for managing CSCF agents using management system based on Fault, Configuration, Accounting, Performance and Security (FCAPS) in the IMS network.

The IP Multimedia Subsystem (IMS) enables converged networking through an application-agnostic architecture that is independent of the access network. The convergence aspects of IMS naturally require a convergent approach to managing the variety of possible applications of IMS. The Navis® element management framework (EMF) shares this application-agnostic architecture principle with IMS and is thus the natural enabler for the required convergent management approach. This paper will explore the development of the management solution for IMS by means of Navis EMF and high-productivity technologies such as Java 2 Enterprise Edition (J2EE <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">∗</sup> ) Enterprise JavaBeans <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">∗</sup> (EJB <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">∗</sup> ), Java <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">∗</sup> , Common Object Request Broker Architecture (CORBA <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">∗</sup> ), and Extensible Markup Language (XML) and will illustrate the application of the management solution in a variety of wireline and wireless solutions, including third-generation (3G) code division multiple access (CDMA) and Universal Mobile Telephone Service (UMTS <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">∗</sup> ) networks. The management solution for IMS is the operations maintenance center-core network (OMC-CN), which is a domain manager for network devices in the IMS network domain.

The IP multimedia subsystem (IMS) is an architectural framework for delivering multimedia in IP network. However, the IMS is less clear regarding the monitoring of performance and fault management; beside the new generation operations systems and software (NGOSS) system manipulate QoS based assurance scenarios with enhanced telecom operations map (eTOM), which describe all management operations for system level monitoring and management (SLM&M), but this specification is generic. In this article, we propose a design of SLM&M, which integrates new technologies in network management, such as WSOA for communication and data processing as business processes; and BPEL to orchestrate the monitoring operation. The first scenario of SLM&M is to monitor supply scenario of multimedia service in IMS network, which is necessary to collect management information. This information leads to the SLM&M to monitor the network behaviour after delivery. In this work, we examine the response time in information collection operation during supply.

IMS (IP Multimedia Subsystem) presents a variety of services and features to meet the needs and expectation of subscribers. This variety of choices presents risks of retrieving non oriented services while responding to subscriber request. This may be due to similarities between services and to the huge amount of available services. In addition to service information, it is possible to extract and explore subscriber information in IMS network. Thus, it becomes interesting to consider, besides of request details, subscriber profile information in service discovery process. This paper presents an overview of our model and its mechanism based upon IMS architecture which provides service discovery combined with proactive service exposure to better respond to subscribers' needs and expectations. The results show improvement of usual state of the art models on several axes.

The 3 GPP IP multimedia subsystem (IMS) is currently expected to provide the basic architecture framework for the next generation network which will bridge the traditional divide between circuit-switched and packet-switched networks and consolidate both sides into one single network for all services. Therefore, the imminent commercial roll-out of IMS will have immense impact on the whole way future mobile business applications are designed, developed and deployed. This paper presents a survey about the application-oriented research project CAMPARI (configuration, architecture, migration, performance analysis and requirements of 3G IMS) which aims at inves-tigating a "minimal-optimal" IMS configuration with respect to architecture and quality-of-service aspects. After a brief survey of the IMS core components, we introduce our OpenSER-based IMS prototype implementation and present the "IMS in a bottle " approach. Based on our practical experiences with this testbed system, we finally discuss important current and future challenges including migration, interworking, charging, identity management, security, and regulatory aspects.