Showing papers on "IP Multimedia Subsystem published in 2016"

Anomaly Detection and Root Cause Localization in Virtual Network Functions

Abstract: The maturity of hardware virtualization has motivated Communication Service Providers (CSPs) to apply thisparadigm to network services. Virtual Network Functions (VNFs)result from this trend and raise new dependability challengesrelated to network softwarisation that are still not thoroughlyexplored. This paper describes a new approach to detect ServiceLevel Agreements (SLAs) violations and preliminary symptomsof SLAs violations. In particular, one other major objectiveof our approach is to help CSP administrators to identify theanomalous VM at the origin of the detected SLA violation, whichshould enable them to proactively plan for appropriate recoverystrategies. To this end, we make use of virtual machine (VM)monitoring data and perform both a per-VM and an ensembleanalysis. Our approach includes a supervised machine learningalgorithm as well as fault injection tools. The experimental testbedconsists of a virtual IP Multimedia Subsystem developed by theClearwater project. Experimental results show that our approachcan achieve high precision and recall, and low false alarm rateand can pinpoint the root anomalous VNF VM causing SLAviolations. It can also detect preliminary symptoms of highworkloads triggering SLA violations.

A Connectionist Approach to Dynamic Resource Management for Virtualised Network Functions

Abstract: Network Functions Virtualisation (NFV) continues to gain attention as a paradigm shift in the way telecommunications services are deployed and managed. By separating Network Functions (NFs) from traditional middleboxes, NFV is expected to lead to reduced CAPEX and OPEX, and to more agile services. However, one of the main challenges to achieving these objectives is on how physical resources can be efficiently, autonomously, and dynamically allocated to Virtualised Network Functions (VNFs) whose resource requirements ebb and flow. In this paper, we propose a Graph Neural Network (GNN)-based algorithm which exploits Virtual Network Function Forwarding Graph (VNF-FG) topology information to predict future resource requirements for each Virtual Network Function Component (VNFC). The topology information of each VNFC is derived from combining its past resource utilisation as well as the modelled effect on the same from VNFCs in its neighbourhood. Our proposal has been evaluated using a deployment of a virtualised IP Multimedia Subsystem (IMS), and real VoIP traffic traces, with results showing an average prediction accuracy of 90%. Moreover, compared to a scenario where resources are allocated manually and/or statically, our proposal reduces the average number of dropped calls by at least 27% and improves call setup latency by over 29%.

New Security Threats Caused by IMS-based SMS Service in 4G LTE Networks

Abstract: SMS (Short Messaging Service) is a text messaging service for mobile users to exchange short text messages. It is also widely used to provide SMS-powered services (e.g., mobile banking). With the rapid deployment of all-IP 4G mobile networks, the underlying technology of SMS evolves from the legacy circuit-switched network to the IMS (IP Multimedia Subsystem) system over packet-switched network. In this work, we study the insecurity of the IMS-based SMS. We uncover its security vulnerabilities and exploit them to devise four SMS attacks: silent SMS abuse, SMS spoofing, SMS client DoS, and SMS spamming. We further discover that those SMS threats can propagate towards SMS-powered services, thereby leading to three malicious attacks: social network account hijacking, unauthorized donation, and unauthorized subscription. Our analysis reveals that the problems stem from the loose security regulations among mobile phones, carrier networks, and SMS-powered services. We finally propose remedies to the identified security issues.

A Load-Balanced Call Admission Controller for IMS Cloud Computing

Abstract: 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.

Cloudifying the 3GPP IP multimedia subsystem for 4G and beyond: A survey

Abstract: 4G systems have been continuously evolving to cope with the emerging challenges of human-centric and M2M applications. Research has also now started on 5G systems. Scenarios have been proposed and initial requirements derived. 4G and beyond systems are expected to easily deliver a wide range of human-centric and M2M applications and services in a scalable, elastic, and cost-efficient manner. The 3GPP IMS was standardized as the service delivery platform for 3G networks. Unfortunately, it does not meet several requirements for provisioning applications and services in 4G and beyond systems. However, cloudifying it will certainly pave the way for its use as a service delivery platform for 4G and beyond. This article presents a critical overview of the architectures proposed so far for cloudifying the IMS. There are two classes of approaches; the first focuses on the whole IMS system, and the second deals with specific IMS entities. Research directions are also discussed. IMS granularity and a PaaS for the development and management of IMS functional entities are the two key directions we currently foresee.

Social-Sensed Multimedia Computing

Abstract: The authors propose the social-sensed multimedia computing paradigm and advocate for the need to organically integrate social network and social media data with multimedia computing tasks. More researchers in the multimedia community should be focusing on the user dimension to quickly advance this line of research.

Network access method and terminal

Abstract: The embodiment of the invention discloses a network access method The method comprises the following steps: acquiring a current geographical location of a terminal and a current time point; determining a VoWiFi (Voice over WiFi) hotspot corresponding to the current geographical location and the current time point from a preset corresponding relation among a geographical location range, a time interval and hotspot information according to the current geographical location and the current time point; and establishing a connection with the VoWiFi hotspot in order to access to an IMS (IP Multimedia Subsystem) network The embodiment of the invention also discloses a network access terminal Through adoption of the embodiment of the invention, the network switching speed can be increased, and the network access security can be enhanced

Voice calling method, voice calling device and terminal

Abstract: The invention provides a voice calling method, a voice calling device and a terminal, wherein the voice calling method comprises the following steps of: determining whether a signal radio voice call continuity (SRVCC) call forwarding instruction is received or not after a voice calling request of an IP multimedia subsystem IMS is initiated; falling back to a 3G network or a 2G network while determining that the SRVCC call forwarding instruction is received; judging whether configuration information of a current cell supports a circuit switch (CS) domain service or not according to the SRVCC call forwarding instruction; and if so, directly executing a CS voice call, otherwise, initiating a location registration process LAU in the current cell. By means of the technical scheme of the invention, the problem that the CS voice call is failed in the event that a 4G network only supports a PS service after being subjected to SRVCC call forwarding and falling back to a 3G or 2G network can be avoided; the calling success rate is increased; and the user experience in the voice calling process is improved.

A Novel Seamless Handover Scheme for WiMAX/LTE Heterogeneous Networks

Abstract: Acquiring seamless handover in IP multimedia subsystem (IMS)-based heterogeneous internetworking environment still remains an unsolved issue. It is highly difficult to achieve seamless handover with the conventional session initiation protocol (SIP) due to its poor performance during vertical handover. In this paper, a novel SIP-based scheme called SIP Prior Handover with a cross-layer design utilizing Media Independent Handover Services is modeled to reduce the IMS session re-setup delay in a Worldwide Interoperability for Microwave Access (WiMAX)/Long Term Evolution (LTE) heterogeneous environment. The proposed scheme further reduces the IMS session re-setup delay by reducing the number of SIP messages exchanged during vertical handover. We have developed a simulating environment using NS2 for a WiMAX/LTE interworking architecture and evaluated its performance. We have also developed a mathematical model for the IMS session re-setup delay based on queuing theory. The simulation results are compared for handover delay, packet loss, SINR and throughput. The proposed design shows an improvement of 18 % when compared with previous approaches during vertical handover from WiMAX to LTE and vice versa and suits well for supporting real-time applications to mobile users.

Towards Black-Box Anomaly Detection in Virtual Network Functions

Abstract: The maturity of hardware virtualization has motivated communication service providers to apply this paradigm to network services. Virtual Network Functions (VNFs) come from this motivation and refer to any virtual execution environment configured to provide a given network service. VNFs constitute a new paradigm and related dependability evaluation mechanisms are still not thoroughly defined. In this paper we propose a preliminary evaluation of an anomaly detection approach applied to VNFs. Our approach uses a supervised machine learning algorithm. It notably relies on data provided by the underlying hypervisor of the VMs hosting the VNF, making it a black-box approach. Such an approach is actually well suited for infrastructure or telecommunication service providers willing to deploy tools that are easily configurable while reducing deployment costs. We validate our approach with the case study of the vIMS (IP Multimedia Subsystem) implemented by the Clearwater project.

Real-time optimized NFV architecture for internetworking WebRTC and IMS

Abstract: Network Function Virtualization (NFV) technology has emerged as a promising solution to optimize the deployment of network elements in cloud computing environment, both in terms of user Quality of Service (QoS) and resource allocation. To deliver IP Multimedia Subsystem (IMS) advanced services across multiple access networks, a cloud-based model likely improves not only flexibility in network management but also in service invocation. This model is particularly suitable for the inter-network between the IMS and Web Real-Time Communication (WebRTC) domain, which is a natural combination to significantly expand potential end-points of multimedia sessions. However, optimally allocating resource for each component in the system to provide QoS is challenging, and has not been fully considered in prior work. In this paper, we investigate an NFV architecture to enable effective communication between IMS and WebRTC users supporting smart community services, and propose an optimization model to design and allocate resources for such system while ensuring desired QoS level. Experimental results show our algorithms effectively allocate required amounts of resources for virtual components according to real-time increase or decrease in user demand.

Analyzing three-party authentication and key agreement protocol for real time IP multimedia server---client systems

Abstract: Authenticated key agreement (AKA) is useful to preserve the secret (private) key for the data being transmitted over an insecure Thus, this paper proposes the strategies, such as short-term and long-term private keys for the three party authentication and key agreement (3PAKA) protocol. Recently, the IP Multimedia server and client systems have been sprung up for the Telecom Industry, though the systems have not had any proficient authentication mechanism for the fulfillment of security properties and mitigation of signal congestion, bandwidth consumption and end-to-end voice call delay. To address this issue, we present a novel 3PAKA that duplicates the long-term and short-term private keys to alleviate the signal congestion of the multimedia systems. It is then analyzed in the real time multimedia server---client systems to examine the metrics realistically. Besides, we employ the strategy of random Challenge-Response (CR) technique to declare the clock synchronization as invalid.

IMS roaming service policies

Abstract: A method including receiving, at a CSCF (Call Session Control Function) portion of a home network in which a mobile station is subscribed, an IMS (IP Multimedia Subsystem) registration request from the mobile station via a visited network to which the mobile station is attached; establishing an SIP (Session Initiation Protocol) session between the mobile station and the CSCF server in response to the received IMS registration request; receiving, at the CSCF server, a SIP INVITE message from the mobile station during the SIP session, wherein the SIP INVITE requests use of a service; obtaining an identifier for the visited network; obtaining, in response to receiving the SIP INVITE message, a first roaming policy based on the identifier for the visited network; determining whether the SIP INVITE message is acceptable based on the obtained first roaming policy and the service requested by the SIP INVITE message; and sending a response for the SIP INVITE message to the mobile station, wherein the response is based on the determination whether the SIP INVITE message is acceptable

Network accelerating device

Abstract: The invention provides a network accelerating device which comprises an accelerating system edge node deployed between an EPS core network and the Internet. The accelerating system edge node comprises a proxy server cluster which is used for perceiving the application type or content of an application layer message and determining a network capacity requirement of an EPS bearer used for transmitting the message according to the type or content, and a NON-IMS AF (non-network protocol IP multimedia subsystem application functional entity) which is connected with the proxy server cluster and used for allocating network resources satisfying the network capacity requirement of the EPS bearer for transmitting the application layer message through coordinating with the EPS core network; or the accelerating system edge node comprises a NON-IMS AF which is used for perceiving and sending the actual network capacity allocated by the EPS core network for the EPS bearer, and a proxy server cluster which is used for configuring a transmitting mode of a transmission layer and each layer thereon in an OSI (open system interconnection) network model for the application layer message according to the actual network capacity allocated for the EPS bearer so as to enable the transmitting mode to be matched with the actual network capacity. The network accelerating device provided by the invention more fits to characteristics of a mobile network than a traditional fixed network accelerating method.

Mobile communication system, communication control device, mobility management entity, and mobile communication method

Abstract: A Home Subscriber Server (HSS) determines whether roaming of voice communication via an IP Multimedia Subsystem (IMS) is supported in the Visited Public Land Mobile Network (VPLMN) or not, and transmits to a mobility management entity (MME) a signal that includes a ‘voice supported’ or ‘voice not supported’ indicator that indicates whether the roaming is supported or not. The MME receives the indicator from the HSS, and transmits to a User Equipment (UE) an ‘Attach Accept’ as a response to an ‘Attach Request’ for the VPLMN. The MME then transmits to the UE, based on the indicator received from the HSS, the ‘Attach Accept’ that includes an indicator that indicates whether the roaming is supported or not.

Inter-ims service support in telecommunication systems

Abstract: A first communication provider supports an IP multimedia subsystem (IMS) having a border session control function (BGCF) that receives SIP requests. The SIP requests correspond to different SIP methods and specify various feature tags. The feature tags correspond to available services or media types that may be available from the IMS of a second communication provider. When receiving a SIP request that addresses a user supported by the second communication provider, the BGCF of the first communication provider checks the method and feature tag of the SIP request to make sure that they are supported by IMS of the second communication provider. If they are not, the SIP is rejected and a failure message is returned. The BGCF may also modify certain parameters of the SIP request, such as by removing one or more offered codecs or preconditions.

Terminating-access domain determining method and server

Abstract: The invention discloses a terminating-access domain determining method and server. The method comprises that a triggered application server (AS) requests the acquisition of terminating-access domain selection (T-ADS) information of a user and an IP multimedia subsystem (IMS) register state from a home subscriber server (HSS), and transmits an IP multimedia public identity (IMPU) to the HSS; the AS receives a request result returned by the HSS, the request result includes a query result, the T-ADS information and the IMS register state, and the T-ADS information and the IMS register state are information acquired through a query by the HSS according to the IMPU; and the AS determines an access domain according to the request result.

Stereotypes based resource allocation for multimedia internet service in limited capacity network

Abstract: Nowadays, Information and Communication Technology (ICT) is widely used in various fields. For an example, education sector also widely utilizes ICT in distance learning process through the use of multimedia conferencing technology. In order to support the multimedia-based services, it is needed sufficient network resources such as good infrastructure and bandwidth availability. In Indonesia, most areas are typically facing several barriers on network infrastructure. Limited bandwidth is one of the main problems to deliver multimedia contents like in distance learning services. In this research, we aim to study on how to deliver multimedia with Quality of Service (QoS) guarantee (minimum delay and packet loss) on the bandwidth-limited network which is typically less than 3 Mbps in Indonesia's rural areas. Moreover, we also aim to study on how to maximize the performance of the existing network. In this research, we use stereotype-based model to classify multimedia stream and allocate existing resources in limited capacity network. This paper will explain how to allocate the available resources using stereotype models for multimedia internet services in a limited capacity networks. From simulation study, the proposed method demonstrates better results when employing proposed method than using iPAS mechanism in low bandwidth network.

A high-performance and scalable distributed storage and computing system for IMS services

Abstract: Because of the rapid growth of the number of mobile user requests and media files on demand, system performance could be negatively impacted and the management of different sorts of media files becomes costly and increasingly difficult. In this article we propose an innovative architecture combining the IP Multimedia Subsystem (IMS) platform and the Hadoop system for use in the distributed storage of IMS service resources and for the purposes of the computing service that is proposed in this work for responding to mobile end-users' needs in terms of mobile computing through the IMS network. As a result, we obtain a controllable Hadoop-based data center for telecommunications service providers. Moreover, for the proposed computing service, MapReduce analysis is also used to create new revenues and improve the IMS computing capabilities. In this article, we present a high-performance and scalable distributed storage and computing system for IMS services through different scenarios of service provisioning, storing and computing processes. Via experiments, the system performance is determined. Furthermore, the experimental results prove the system availability and scalability by sharing out more distributed resources for further IMS services using Hadoop Distributed File System (HDFS), YARN, and the Hadoop distributed cache mechanism. The proposed architecture in addition considerably minimizes response time, maximizes throughput and server utilization gets improved.

High available deployment of cloud-based virtualized network functions

Abstract: As Cloud technologies mature increasingly, more businesses tend to migrate their services towards Infrastructure-as-a-Service platforms instead of dedicated data centers. Recently, even telecommunication providers consider moving their services to the Cloud despite the high demands regarding service quality. In order to deploy such critical services using mainstream Cloud management software, it must be hardened to deliver the required degree of availability and performance. In this paper we present a reliable deployment scheme for the Cloud software OpenStack with an IP Multimedia Subsystem on top simulating telecommunication services. We derived a top-down analysis approach to evaluate the deployed scheme in the context of typical carrier-grade service scenarios. Furthermore we identified the shortcomings of the system to fulfill the requirements of Virtualized Network Functions in terms of failure tolerance and recovery cost.

Communication processor, method for realizing VoLTE, mobile terminal and data card

Abstract: The invention provides a communication processor, a method for realizing VoLTE (Voice over LTE), a mobile terminal and a data card. The communication processor comprises a wireless protocol stack entity, a VoLTE function control module, a voice coding and decoding module, an IMS (IP Multimedia Subsystem) protocol stack entity and a TCP/IP (Transmission Control Protocol/Internet Protocol) stack entity. The VoLTE function control module interacts with the voice coding and decoding module, the IMS protocol stack entity and the wireless protocol stack entity in terms of control messages. The TCP/IP stack entity interacts with the wireless protocol stack entity and the IMS protocol stack entity in terms of TCP/IP data. The voice coding and decoding module interacts with external audio equipment in terms of audio data and control messages, and interacts with the IMS protocol stack entity in terms of audio data. According to the VoLTE realizing scheme, different product forms can be supported, the power consumption is reduced, and requirements of communication devices between an AP (Application Processor) and a CP (Communication Processor) are minimized.

Multimedia Content Delivery in OpenFlow SDN: An Approach Based on a Multimedia Gateway

Abstract: Day after day, multimedia applications and services are becoming more and more popular, making the network traffic more detailed and complex. In this scenario, the multimedia content delivery is challenging and a proper method to increase the distribution efficiency is nearly mandatory. In this paper, we explore a multimedia gateway to enhance the multimedia content delivery in an OpenFlow Software-Defined Network (SDN) environment. On the network, the multimedia gateway acts as a complementary component of the OpenFlow controller and as a network gateway for the end-systems. The interactions with the OpenFlow controller occur via its northbound API. Through these interactions, with global information of the network, multimedia traffic flows can be routed and delivered differently from the other flows. Our evaluation experiments show that the multimedia gateway is able to identify and classify multiple multimedia traffic flows according to their service type (e.g., audio, voice, video or data), forward each traffic flow to the destination system according to specific flow rules, with different configurations of bandwidth allocation and of priority, and provide a caching service for the end-systems. These resources are important to improve the multimedia content delivery and distribution and to increase the user-perceived Quality of Experience (QoE).

A Fuzzy Search Based Joint Dual Mobile Service Discovery and Exposure Model

Abstract: IMS (IP Multimedia Subsystem) contains a variety of services and information to better fit the needs and expectation of subscribers. Based on the fact that IMS subsystem contains huge amount of available services and that similarities between them are current, we should consider risks of discovering and exposing services that may not be well oriented to subscriber profile. Beside service information, IMS presents the possibility of extracting and exploring subscribers' information. Thus, it becomes interesting to consider these information beside service information in discovery and exposure processes. This paper presents an overview of our proactive advanced service discovery exposure broker (Advanced JDMS-DEMO) and its mechanism based on search approaches that combines information about services with subscribers' profiles information to reduce the gap between subscribers' needs and discovered services. Results show improvement compared with usual researches and models on several axes.

Iterative traffic engineering in the data plane of multimedia IP communications

Abstract: The quality of multimedia communications heavily relies on the end-to-end network condition. Sub-optimal resource allocation in the substrate network may deplete certain links sooner, making the network less resilient to link failures, traffic fluctuation or random traffic spikes. Regulating the traffic can improve the media quality, but is not an easy operation to do in legacy IP networks. SDN technology provides the support for an unprecedented centralized solution in this regard. Thus the biggest challenge is how to allocate resources in the data plane. In this paper, we propose a Two-phase flow embedding approach with an iterative traffic engineering algorithm to address the resource allocation problem lying in the data plane of multimedia IP communication systems. We numerically evaluate it and compare it with (a) Dijkstra algorithm and (b) flow embedding approach with a greedy TE heuristics. We show that the flow embedding approach with the iterative TE excels in all three metrics: session accept rate, throughput, and link utilizations, under a spectrum of scenarios including unexpected network conditions and traffic conditions.

Method and system for acquiring terminal communication state in IMS (IP multimedia subsystem) and application server

Abstract: The invention discloses a method and a system for acquiring the terminal communication state in an IMS (IP multimedia subsystem) and an application server, and relates to the technical field of IMS applications. The method comprises the steps that a terminal communication state acquisition platform sends a target terminal state subscription request to a multimedia telephone application server; the multimedia telephone application server acts as a terminal communication state information source and sends current communication state information of a target terminal to the terminal communication state acquisition platform; and the target terminal communication state changes, and the multimedia telephone application server sends target terminal communication state update information to the terminal communication state acquisition platform, thereby realizing that the terminal communication state acquisition platform acquires continuous communication state change information of the target terminal from the multimedia telephone application server in real time.

Voice message leaving method and device based on IMS (IP Multimedia Subsystem) network

Abstract: The invention provides a voice message leaving method and device based on an IMS network. A called terminal confirms whether a call terminal is a voice verification object through receiving and forwarding a call request to the called terminal; if so, a voice verification resource is obtained; the call terminal is verified; if the call terminal feeds back a first marking code, a unidirectional voice message leaving channel is built between the called terminal and the call terminal; the call terminal leaves a voice message to the called terminal; if a second marking code is received, a bidirectional call channel is built between the called terminal and the call terminal, the called terminal and the call terminal mutually send and receive voice signals. Real time voice message leaving and playing are provided for the incoming call of the call terminal in the ringing process of the phone; bidirectional conversation is realized under the condition that the called user knows the incoming call purpose of the call terminal through listening to the message; the user can predict the incoming call purpose before answering the call, the incoming call answering efficiency is improved, and the user experience is promoted.

Voice conversation bearing method and device

Abstract: The embodiment of the invention discloses a voice conversation bearing method and device. The method comprises the steps that after a terminal initiates a voice call, the network signal quality and the network congestion level of the currently registered network of the terminal are acquired, and the terminal is a terminal which signs an IP multimedia subsystem IMS service; and when the network signal quality is greater than a quality threshold and the network congestion level is less than a congestion threshold, a default bearer is adopted to perform transmission of voice conversation data, and the voice conversation data are data generated in conversation after the success of the voice call. With application of the voice conversation bearing method and device, the defects that the voice service of the existing VoLTE schemes fails to make full use of bearing resources can be solved, and cost of the voice service can be reduced.

An IMS-based LTE-WiMAX-WLAN architecture with efficient mobility management

Abstract: In this paper, a framework is proposed for interworking LTE, WiMAX and WLAN using IP Multimedia Subsystem (IMS) on top of the three technologies. The aim is to provide high quality real-time multimedia services during handoff. The proposed mobility management technique uses Mobile IP (MIP) and Session Initiation Protocol (SIP) together with IMS, which proves to maintain the continuity of an on-going session and data access during roaming between the different radio access technologies. A comparison between the proposed tight coupled architecture using MIP-SIP and the same tight coupled networks using SIP-based mobility management is presented. OPNET Modeler 17.1 is used to simulate the networks. Results show that the total average packet loss is reduced considerably during VoIP sessions using MIP-SIP in the proposed network.

Verification of the Analytical Traffic Model of a Multidomain IMS/NGN Using the Simulation Model

Abstract: In this paper we verify the previously proposed analytical traffic model of a multidomain Next Generation Network (NGN), which is standardized for delivering multimedia services based on the IP Multimedia Subsystem (IMS). For this reason a proper simulation model used, in which not theoretical queuing system models but the operation of real network elements and standardized call scenarios are accurately implemented. Consequently, the simulation model reflects the phenomena taking place in real IMS/NGN network and can be considered as a reference for evaluation of quality of the analytical results. The output variables assessed using both models are mean Call Set-up Delay (CSD) and mean Call Disengagement Delay (CDD), a subset standardized call processing performance parameters. The investigations are performed for various types of calls and sets of network parameters. As a result, conclusions regarding conformity of the analytical and simulation results in a multidomain IMS/NGN are presented.