This Special Issue contains extended versions of selected papers from 4th International Workshop on Reliable Networks Design and Modeling (RNDM 2012) held in St. Petersburg, Russia on October 3–5, 2012. This event was organized by Gdansk University of Technology (PL) in cooperation with Ghent University (BE), and NTT/Nippon Institute of Technology (JP). The workshop was technically co-sponsored by IFIP TC6 WG 6.10 and by IEEE Region 8.

Similar to previous editions, RNDM 2012 was a forum for discussions between people from academia and industry with special focus on network survivability, i.e., capability of a network to provide the continuous transmission after failures.

After a careful review process, including on average 4.2 completed reviews per each paper, RNDM 2012 papers selected for publication were organized into seven technical sessions, namely: ”Resilience of IP-based Networks”, ”Optical Networks Survivability”, ”Resource Sharing”, ”End-to-end Resilience”, ”Network Reliability Evaluation”, ”Emerging Areas in Reliable Networks Design”, and ”Resilience of Virtual and Overlay Networks”.

After the event, presented papers were carefully examined again by the Chairs. As a result, authors of eight selected papers were invited to submit the extended versions to this Special Issue. These extended papers were also extensively reviewed. Their final acceptance was conditional upon carefully addressing the reviewers remarks. Each of the papers is briefly introduced below.

The first paper entitled Future Research Directions in Design of Reliable Communication Systems by Rak et al. discusses new trends in the design of reliable communication systems with special focus on software failure mitigation, reliability of wireless communications, robust optimization and network design, multilevel and multirealm network resilience, multiple criteria routing approaches in multilayer networks, resilience options of the fixed IP backbone network in the interplay with the optical layer survivability, reliability of cloud computing networks, as well as resiliency of software-defined networks.

In Quantification of System Survivability, Trivedi and Xia introduce the notion of survivability focusing on the capability of a system to achieve timely recovery in the face of adverse incidents.

Okamura et al. in Network Survivability Modeling and Analysis for Power-aware MANETs by Markov Regenerative Processes present the quantitative network survivability analysis for a power-aware mobile ad hoc network (MANET) based on Markov regenerative processes (MRGPs). In particular, a power-aware MANET model is revisited by using MRGP, and both stationary and transient analysis for the MRGP-based model is presented.

The next paper entitled On Providing Fast Protection with Remote Loop-Free Alternates—Analyzing and Optimizing Unit Cost Networks by Csikor and Retvari focuses on providing fast restoration using the concept of remote loop-free alternates (rLFA), which is an extension to the conventional LFA technique. In particular, their research determines the topological requirements and the protection efficiency of Remote LFA as well as finds optimization methods to tweak the network for 100 % rLFA failure case coverage.

Staessens et al. in Analysis of Resource Sharing in Transparent Networks concentrate on reducing the capital expenditures (CapEx) expected from implementing sharing of backup resources in path-protected transparent networks. A nationwide network topology is dimensioned for different protection mechanisms using transparent and opaque architectures. In particular, the authors show that the possible gain for transparent networks strongly depends on the network load.

Multilevel Resilience Analysis of Transportation and Communication Networks by Çetinkaya et al. includes graph-theoretic analysis of physical infrastructures using the spectral properties. Moreover, it proposes a framework to realistically model and analyse robustness of multilevel and multiprovider networks.

Girlich et al. in On the Resistance of Overlay Networks against Bandwidth Exhaustion Attacks present metrics to evaluate network topologies in terms of resistance against botnets. In particular, the metrics included in the paper refer to random, greedy, as well as optimally operating attackers.

The last paper entitled Flow Assignment (FA) and Capacity and Flow Assignment (CFA) Problems for Survivable Overlay Multicasting in Dual Homing Networks by Kmiecik and Walkowiak focuses on using the overlay multicasting approach for the purpose of safe transmission of critical data. The authors show that additional survivability requirements do not imply a significant increase of the streaming/network cost.

The papers included in this Special Issue were selected in hope that they show the big picture of the best ideas on network reliability presented during RNDM 2012. The editors of this Special Issue would like to express their gratitude to the Editor of Telecommunication Systems journal for his consent to publish RNDM 2012 materials in this Journal, as well as to the reviewers for delivering the detailed reviews.