Abstract Poison message failure is a mechanism that has been responsible for large‐scale failures in both telecommunications and IP networks. We design a fault management framework that integrates passive diagnosis and active diagnosis to identify the poison message and prevent network instability. Passive diagnosis uses real‐time inference and reasoning techniques to analyze network information and generates a probability distribution of the poison message, and the probability distribution is used in active diagnosis for further failure identification. In active diagnosis, message filtering is used to block suspect message types. Blocking messages affects network performance and service. The tradeoff of message filtering is formulated as a Markov Decision Process (MDP). The large size of the state space makes it impractical to use traditional techniques to solve the MDP. Con sequently, we use a combination of reinforcement learning and feature‐based function approximation to obtain a suboptimal policy. Extensive simulations demonstrate the effectiveness of passive diagnosis, and show that the suboptimal policy performs significantly better than a well‐known heuristic policy. Copyright © 2008 John Wiley & Sons, Ltd.

We address the requirements and design of bandwidth on demand networks in the context of Grid services. Regardless of the deployment scenario for Grid services (e.g., commercial or research), there is a need for efficient use of network facilities and a need to meet the performance requirements of the Grid services users. We present quantitative analysis showing how these needs can be met.

Large networks relying on real-time processing can be driven into unstable modes of operation (e.g., routing system failures, routing flaps, congestion and deadlock scenarios, system crash chain reactions, etc.). In the past, unintentional system faults have led to frame relay networks, SS7 signaling networks, and PSTNs going into unstable modes that have led to major service disruptions. A serious concern is that a malicious party could induce similar instabilities. The vulnerability of a network to instabilities may be due to unrecognized design flaws or hidden software bugs. Since these details are not known in advance, effective control mechanisms tailored to the specifics of the vulnerability are virtually impossible to achieve. However, it is our contention that there are a limited number of "generic propagation mechanisms" that enable these network instabilities to occur. By enumerating these propagation mechanisms and designing network management and control mechanisms to mitigate them, it would be possible to stabilize networks against malicious attack even when the details of the network vulnerability being exploited are unknown. We focus on a single example of a generic propagation mechanism that can occur in IP and ATM networks using link state routing protocols. The propagation mechanism is overload propagation in the control plane caused by excessive route updates. Network management and control mechanisms for mitigating this propagation mechanism are developed and validated through simulation of both the control and data planes.

An introductory article covers SS7 protocol, services, reliability, performance, and congestion control. Following the introductory article, the papers are arranged in three sections. The largest section is on performance analysis and congestion control. The papers in the second section address several issues relevant to the network level, including the impact of new services. The last section of this issue contains papers that highlight technical issues for future studies. This section carries a dual purpose: to introduce the preliminary results achieved by the authors and to suggest directions for additional work in this area.>

Signaling System No. 7 (SS7) is designed to provide a connectionless transfer of signaling messages of reasonable length. Customers having access to user signaling bearer capabilities as specified in the ANSI T1.623 and CCITT Q.931 standards can send bursts of correlated messages (e.g., by doing a file transfer that results in the segmentation of a block of data into a number of consecutive signaling messages) through SS7 networks. These message bursts with short interarrival times could have an adverse impact on the delay performance of the SS7 networks. A control mechanism, credit manager, is investigated in this paper to regulate incoming traffic to the SS7 network by imposing appropriate time separation between messages when the incoming stream is too bursty. The credit manager has a credit bank where credits accrue at a fixed rate up to a prespecified credit bank capacity. This paper presents simulation results showing delay performance of the SS7 ISUP and TCAP message traffic with a range of correlated message traffic, and control parameters of the credit manager (i.e., credit generation rate and bank capacity) are determined that ensure the traffic entering the SS7 network is acceptable. The results show that control parameters can be set so that for any incoming traffic stream there is no detrimental impact on the SS7 ISUP and TCAP message delay, and the credit manager accepts a wide range of traffic patterns without causing significant delay.>

The authors wish to provide a unification of this issue's papers by providing a clear context for them. Common channel signaling can be defined as the system that enables stored program control exchanges, network databases, and other nodes of a network to exchange messages related to call setup, supervision, and take down (call and connection control information); information needed for distributed application processing (interprocess query and response or user-to-user data); and network management information.>

An overview of Signaling System No.7 (SS7) is presented. The salient features of SS7's network services part (NSP) are described. Functionally, NSP corresponds to the first three layers of the Open System Interconnection (OSI) reference model. The signaling network structures that, in conjunction with the NSP, provide integrated services digital network (ISDN) nodes with a highly reliable and efficient means of exchanging signaling messages are discussed. The nodal capabilities of call control and remote process invocation and management, part of the SS7 user parts, are described. The very stringent performance requirements of signaling systems and their reflection on the critical nature of signaling functions and their real-time exigencies are discussed. The likely evolution of network signaling in the remaining years of the 20th century is discussed.>