Networking became the key economical factor in bridging countries and cultures, speeding the economy, and synchronizing the research topics across multi-national groups and universities. The International Conference on Networking (ICN) held in Mauritius, April 23-28, 2006 became now a reference in the networking community and provided an international forum for discussions between researchers, practitioners and students interested in new developments targeting all areas of networking. ICN 2006 was the 5th conference of this successful series and was organized and technically co-sponsored by the IEEE, IEE and IARIA organizations with proceedings published by the IEEE Computer Society Press. As with the previous editions, this event continued to be very competitive in its selection process and very well perceived by the international networking community. As such, it is attracting excellent contributions and active participation from all over the world. This year more than 390 submissions were reviewed by the members of the technical program committee and about 40% were finally accepted for presentation at the conference. We were very pleased to receive a large amount of top quality contributions. The accepted papers cover a wide range of networking related topics spanning from VoIP, NAT and SIP to OLSR, DDoS, H.264, QoS, policy traffic management and routing. We believe that the ICN-2006 papers offered a large panel of solutions to key problems in all areas of networking and set challenging directions for industrial research and development.

Proceedings of the 5th International Conference on Networking

Securing VoIP is a crucial requirement for its successful adoption. A key component of this is securing the signaling path, which is performed by SIP. Securing SIP is accomplished by using TLS instead of UDP as the transport protocol. However, using TLS for SIP is not yet widespread, perhaps due to concerns about the performance overhead. This paper studies the performance impact of using TLS as a transport protocol for SIP servers. We evaluate the cost of TLS experimentally using a testbed with OpenSIPS, OpenSSL, and Linux running on an Intel-based server. We analyze TLS costs using application, library, and kernel profiling, and use the profiles to illustrate when and how different costs are incurred, such as bulk data encryption, public key encryption, private key decryption, and MAC-based verification. We show that using TLS can reduce performance by up to a factor of 17 compared to the typical case of SIP-over-UDP. The primary factor in determining performance is whether and how TLS connection establishment is performed, due to the heavy costs of RSA operations used for session negotiation. This depends both on how the SIP proxy is deployed (e.g., as an inbound or outbound proxy) and what TLS options are used (e.g., mutual authentication, session reuse). The cost of symmetric key operations such as AES, in contrast, tends to be small.

/pdf/the-impact-of-tls-on-sip-server-performance-slcpux1rnb.pdf

The impact of TLS on SIP server performance

Systems and methods for enhancing security of single sign-on are described. These systems and methods can reduce the amount of sensitive information stored on a client device while still providing single sign-on access to shared resources such as virtual desktops or Terminal Servers. For example, storage of authentication information on client devices can be avoided while still allowing client devices to connect to the shared resources. Instead, such information can be stored at a broker server that brokers connections from client devices to the shared resources. The broker server can facilitate more secure single sign-on by providing a single-use ticket to a client device that authenticates with the broker server. The client device can use this single-use ticket to authenticate with a shared resource.

Single sign-on system for shared resource environments

Providing Quality of Service (QoS) differentiation in future IP-based networks is closely linked to the concurrent implementation of appropriate pricing and charging mechanisms. Thus, in recent years, a broad range of QoS-based charging mechanisms have been proposed, ranging from Paris Metro Pricing and effective bandwidth pricing to the Cumulus Pricing Scheme or the Contract and Balancing Mechanism. However, the strongly increasing interest in Quality of Experience (QoE/QoX) so far has not led to a comparable burst of research activity in the Internet Economics community. Therefore, in order to highlight this important paradigm shift from a charging perspective, we first will review the most prominent QoS-based charging schemes and provide some discussion on lessons learned. In the next step, we describe the imminent transition from QoS to QoX from an economic point of view and discuss recent proposals for pricing of QoX. The paper ends with an outlook on current and future work in this highly interesting research field.

From charging for Quality of Service to charging for Quality of Experience

Telecommunications research can no longer be considered to be pure communications engineering. The convergence of fixed-line and mobile telephony with the Internet together with the rise of novel technologies for rapid service creation has made economic efficiency and user acceptance/usability to crucial factors for the success of the telecommunication business as such. In the emerging new paradigm, a holistic view onto the entire value chain from basic architectural concepts over the efficient design and implementation of new services and applications up to the end customer is becoming indispensable. Within this broad interdisciplinary field, the present paper focuses on the evolution of corresponding concepts for service quality. Whereas the traditional notion of 'QoS' (Quality-of-Service) is already well-established and has led to a plethora of research work mainly in the area of network architectures and protocols, the quality of service design ('QoD') has by far not received comparable attention in the research community. Nevertheless, we argue that both concepts are equally important for achieving a sufficient quality of user experience ('QoE') which eventually leads to both economic viability and user satisfaction. To illustrate our claim, we discuss recent developments in the area of QoS-enabled next generation network architectures as well as novel user-centric service design paradigms, examples for the resulting QoE evaluations and a novel HCI lab approach which allows flexible user tests of mobile applications "in the wild".

From ‘Quality-of-Service’ and ‘Quality-of-Design’ to ‘Quality-of-Experience’: A holistic view on future interactive telecommunication services

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.

"IMS in a Bottle": Initial Experiences from an OpenSER-based Prototype Implementation of the 3GPP IP Multimedia Subsystem

The 3GPP 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 There-fore, the imminent commercial roll-out of IMS will have immense impact both for the migration of the core network as well as the integration of future mobile services and applications This paper presents an OpenSER-based experimental testbed which has been designed as a minimal standard-compliant IMS core network We discuss major practical requirements and describe our implementation of this "IMS in a bottle" approach Furthermore, we introduce a terminal-based native IMS location service enabler We argue that physical location data can be regarded as a type of presence information and propose an architecture which reuses a large part of the IMS presence infra-structure by applying presence mechanisms, like notification handling, access control and privacy management, to location data We demonstrate that the realization of this service can be integrated efficiently into the IMS core environment, and present initial evaluation results for the joint demonstrator Finally, important current and future challenges including migration, interworking, charging, Quality-of-Service, identity management, security, and regulatory aspects, are discussed in detail, thus ending up with an up-to-date research agenda

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Practical experiences with an IMS-aware location service enabler on top of an experimental open source IMS core implementation

Due to the assistance of the mobile IPv6 approach, a mobile node can effectively maintain its IP-layer connectivity to the Internet when it changes its point-of-attachment somewhere in the world. During the accomplishment of the handover, the mobile node is unable to send or even receive IPv6 packets, both due to its L2 and also L3 handover operations. In this paper, the author discussed the different types of handovers, given as fast handover for IEEE 802.11, enhanced WLAN handover, and fast mobile IPv6 approach. Each implementation is configured to access a point involved with a special SSID string that provides all the information about the prefix of the attached AR in the background. Whenever the mobile node anticipates some upcoming handoff, the handover-tool is automatically informed about the prefix of the new AP. In that way the mobile node performs "anticipative" configuration of the new IP address on the new subnet by using the router prefix information carried in the beacon message of the new AP.

Link-layer support for fast mobile IPv6 handover in wireless LAN based networks

Quality of Service impairments in wireless and wired access networks for IP-based next generation networks (NGNs) differ fundamentally from the ones which we typically encounter in core networks. Examples include but are not limited to high delay, low bandwidth, and high jitter. Even though most NGN architectures claim to be access-agnostic, applications deployed on NGNs have requirements which may not be met by specific access technologies. This raises the need to test NGN application prototypes on user acceptance for a huge number of possible access technology combinations. Unfortunately, tests relying on real access network implementations are expensive and time-consuming while simulation at physical or logical link layer are subject to complex parameter configuration. In this paper we present a distinct approach which bases on the sound theoretical background of the IETF IP Performance Metric (IPPM) framework. We argue that careful analysis of performance metrics in existing public access networks can capture access network properties which are sufficiently accurate to model "typical" access links at IP-layer level using either emulation or simulation. We propose a three-step model which starts with metric and methodology selection, continues with parameter acquisition by means of measurements in existing access networks, and ends with emulation or simulation of this access network. The goal of our process is to provide NGN application developers with means to automatically test their applications from the very beginning on the compatibility with various access network technologies, covering both, signaling and data streaming aspects of access networks. We illustrate the procedure using performance measurement results of a public UMTS Release 5 network and UMTS access network emulation by an extended open-source delay emulator.

A Generic Approach to Access Network Modeling for Next Generation Network Applications

The convergence of wireless networking and IP networking more and more requires solutions for transporting real time application data to IP enabled mobile devices and mobile networks. Even if the ingenious mobile IPv6 protocol performs sufficient in macro environments with non real time traffic, seamless mobility requires some more enhanced protocol procedures in between the mobile node and the involved network entities. Limiting the effect of handovers has the potential to considerably improve handover performance in terms of latency and packet loss. This contribution is going to present an extensive simulation study via ns-2 on the performance of the hierarchical mobile IPv6 approach. The demonstrated simulation scenarios comprise up to nine access routers and up to 70 mobile nodes that communicate in accordance with the popular IEEE 802.11 wireless LAN standard, as one of the possible wireless access networks in a future all-IP network infrastructure. The study provides quantitative results of the performance metrics as observed by one single mobile node that may either move deterministically or randomly while the other MNs follow a random movement pattern all the time, providing realistic "interference" with respect to the observed mobile node.

http://ieeexplore.ieee.org/iel5/10360/32962/01543859.pdf

Alexander Poropatich

Papers

"IMS in a Bottle": Initial Experiences from an OpenSER-based Prototype Implementation of the 3GPP IP Multimedia Subsystem

Practical experiences with an IMS-aware location service enabler on top of an experimental open source IMS core implementation

Link-layer support for fast mobile IPv6 handover in wireless LAN based networks

A Generic Approach to Access Network Modeling for Next Generation Network Applications

Performance evaluation of the hierarchical Mobile IPv6 approach in a WLAN hotspot scenario