Network Virtualization implies the need for sharing network resources. However, exclusive resource allocation to users drives blocking probabilities and cost while potentially leaving precious resources under-utilized in constrained environments. Motivated by these observations, this paper analyzes careful overbooking according to Service Level Agreements that specify desired degrees of availability. Besides of full availability of the requested resources, a second level of limited availability, implying a well-defined reduction of the allocated resource, is taken into account. Particular attention is paid to the gain borderline, representing the possibility of accommodating one extra user beyond exclusive allocation without violating the SLAs. Simple but telling formulae provide insights into requirements for careful overbooking, worst-case capacity reduction factors from full to limited availability, and the conditions under which it is sensible to integrate users with different activity levels. We also link capacity reductions to potential decreases in Quality of Experience.

Internet has shown to be the major enabler for a large variety of services via a common infrastructure. Since early applications such as remote login, e-mail, file transfer and web browsing, many new applications and services have entered the stage, where overlay networks play an important role. When broadband access technologies reached private users, file sharing became popular. Telecommunication providers have discovered internet technology as a cost-saving alternative to classical telecom technology. 3GPP has standardised the IP multimedia system (IMS), which is nowadays also used in the world of fixed access networks to handle the coexistence of voice, TV and internet (so-called Triple Play) on access links. New application domains such as e-health, e-government, e-tourism, etc., have emerged. Many new services use other services, forming composite services or service supply chains based on internet. So, the ‘anything-over-IP-over-anything’ principle has become a reality. This emergence of new applications raises challenges. The internet has never been designed for fulfilling all imaginable application’s needs, nor to maximise user’s quality of experience (QoE). During the years, the basic best-effort paradigm has been enhanced by network-level quality of service (QoS) measures. Still, internet packet delivery cannot be guaranteed. Applications try to adapt themselves to these volatile conditions, e.g., by modifying the intensity of the data flows or adding some kind of redundancy to be used for error correction, which fits the internet principle of end-to-end control. However, in order to reach the right interplay between applications and services and the internet infrastructure, a good understanding of the characteristics of both is mandatory. On this background, this special issue focuses on performance assessment of contemporary, new and emerging applications and services using the internet.

Today, many people share personal information through online social networks. While these networks offer tremendous facilities to share one's life with family, friends and the outer world, users are also exposed to the risk to get their accounts compromized, with consequences for their professional and private lives. A strong password can help to ensure privacy, while in contrast, a weak password may lead to a compromized account. On the other hand, it is observed that users tend to shortcut laborious and time-consuming security measures, which alleges that their perception of their safety on the social network might deviate from the real safety situation. In this article, we investigate how users of social networks perceive safety, and to which extent they contribute to it. First, we examine the question in which way and to which extent a user's perception of safety is affected by increased response times. An investigation was conducted for teenage users of the online social network Facebook. Its results indicate that the users' perception of safety differs significantly in face of increased response times that usually imply worse Quality of Experience. Second, in order to find out to which extent users are aware of the risks associated with weak passwords as well as what measures have been taken to keep themselves secure and to ensure privacy, a survey about password complexity in online social networks was conducted with Swedish users. Our results of the survey indicate differences in password complexity between teenagers with different levels of technical education.

The Internet of Things(IoT) will revolutionize the Future Internet through ubiquitous sensing. One of the challenges of having the hundreds of billions of devices that are estimated to be deployed would be rise of an enormous amount of data, along with the devices ability to manage. This paper presents an approach as a controller solution and designed specifically for autonomous management, connectivity and data interoperability in an IoT gateway. The approach supports distributed IoT nodes with both management and data interoperability with other cloud-based solutions. The concept further allows gateways to easily collect and process interoperability of data from IoT devices. We demonstrated the feasibility of the approach and evaluate its advantages regarding deep sensing and autonomous enabled gateway as an edge computational intelligence.