Multiclass IP networks open new dimensions and challenges on active monitoring as efficient strategies of in-band probing are required to sense each class performance without causing noticeable side-effects on real traffic. In our study, we provide new insights on how to perform efficiently active monitoring in these networks, suggesting the use of light and multipurpose probing streams able to capture simultaneously the behavior of multiple QoS metrics of each class. Considering oneway -delay, jitter and loss metrics, we explore different spatial-temporal characteristics of probing, focusing on finding patterns adjusted to each class measurement requirements. We demonstrate that commonly used probing streams fail to capture these metrics simultaneously and we propose novel colored probing patterns able to increase multipurpose active monitoring efficiency. As test environment, we consider a diffserv domain where admission control resorts to feedback from edge-to-edge active monitoring to dynamically control hard real-time, soft real-time and elastic traffic classes. Comparing graphically and statistically the probing and passive measurement outcome of each class, the obtained results show that despite being difficult to match the scale and shape of multiple metrics, a single and properly colored probing stream can capture close and simultaneously the behavior of one-way-delay, jitter and loss, for low in-band probing rates.

Most of the network service specifications use XML based models. However, as XML imposes a hierarchical structure, several types of relations may not be modeled. Therefore, richer specification languages are required in order to specify all network services vocabulary and how it relates with management tasks and with network configuration. This paper presents an ontology based model for network services, overcoming those semantic gaps and creating a better ground for reasoning over services fostering their self-configuration.

Internet service providers usually express the quality of network services through a set of values determined according to several network performance parameters periodically collected or measured. However, for common end-users, these values do not give an overall idea of the quality of the network services as they stand for different units and evaluate different perspectives of each service quality. In this context, this paper proposes the definition of a serviceoriented unified metric which quantifies a global Quality of Service (QoS) indication by processing standard QoS parameters through a fuzzy controller. The proposed methodology, based on fuzzy logic and tested on Xfuzzy 3.0 platform, allows to close the gap between a high-level QoS perspective and the effective QoS measurements at lower protocolar levels. The definition of a single per-service QoS metric can be useful to simplify control tasks such as QoS routing, SLA negotiation and auditing.

Abstract—In multiservice networks, admission control (AC) is a convenient means of assuring high quality communications by safeguarding enough availability for customer traffic. This can be particularly useful to preserve the quality of services such as IP telephony and video conferencing, and to ensure acceptable throughput to elastic flows. This paper tackles the problematic of performing implicit AC in multiservice networks, pointing out a flexible yet simple to deploy solution for controlling flows which do not explicitly send signaling admission requests. This allows to complement the explicit AC case, widening the ability to integrate services and applications in a transparent way. The versatility and self-adaptability of the proposed distributed AC criteria in ensuring the quality of multiple services is also proved. I.

This paper proposes a generic AQM (Active Queue Management) control methodology in TCP/IP networks, based on fuzzy logic control. A simple, effective and efficient nonlinear control law is built, using a linguistic model of the system, rather than a traditional mathematical model, which is easily adapted in different network environments (e.g. Best-Effort and Differentiated-Services architectures). We demonstrate, via extensive simulative evaluation, that the proposed fuzzy control methodology offers inherent robustness with effective control of the system under widely differing operating conditions, without the need to (re)tune the settings for two different architectures (Best-Effort and Differentiated-Services). As demonstrated, this is in contrast with the well-known conventional counterparts of A-RED, REM, PI, AVQ for Best-Effort, and two-level PI, RIO for Diff-Serv based networks, where the proposed approach outperforms all tested counterparts in each different architecture. Keywords: Fuzzy Logic Control, TCP/IP, AQM, congestion control, Diff-Serv 1.

for Capacity-Admitted Traffic This document requests one Differentiated Services Code Point (DSCP) from the Internet Assigned Numbers Authority (IANA) for a class of real-time traffic. This traffic class conforms to the Expedited Forwarding Per-Hop Behavior. This traffic is also admitted by the network using a Call Admission Control (CAC) procedure involving authentication, authorization, and capacity admission. This differs from a real-time traffic class that conforms to the Expedited Forwarding Per-Hop Behavior but is not subject to capacity admission or subject to very coarse capacity admission. Status of This Memo This is an Internet Standards Track document. This document is a product of the Internet Engineering Task Force (IETF). It represents the consensus of the IETF community. It has received public review and has been approved for publication by the

This memo provides information for the Internet community. It does not specify an Internet standard of any kind. Distribution of this memo is unlimited. IESG Note This RFC is not a candidate for any level of Internet Standard. The IETF disclaims any knowledge of the fitness of this RFC for any purpose and notes that the decision to publish is not based on IETF review apart from IESG review for conflict with IETF work. The RFC Editor has chosen to publish this document at its discretion. See RFC 3932 for more information. This memo analyzes provider-to-provider Quality of Service (QoS) agreements suitable for a global QoS-enabled Internet. It defines terminology relevant to inter-domain QoS models. It proposes a new concept denoted by Meta-QoS-Class (MQC). This concept could

Baseline Encoding and Transport of Pre-Congestion Information The objective of the Pre-Congestion Notification (PCN) architecture is to protect the quality of service (QoS) of inelastic flows within a Diffserv domain. It achieves this by marking packets belonging to PCN-flows when the rate of traffic exceeds certain configured thresholds on links in the domain. These marks can then be evaluated to determine how close the domain is to being congested. This document specifies how such marks are encoded into the IP header by redefining the Explicit Congestion Notification (ECN) codepoints within such domains. The baseline encoding described here provides only two PCN encoding states: Not-marked and PCN-marked. Future extensions to this encoding may be needed in order to provide more than one level of marking severity. Status of This Memo This document specifies an Internet standards track protocol for the Internet community, and requests discussion and suggestions for improvements. Please refer to the current edition of the "Internet Official Protocol Standards " (STD 1) for the standardization state and status of this protocol. Distribution of this memo is unlimited. Copyright Notice Copyright (c) 2009 IETF Trust and the persons identified as the

This paper debates the problem of handling concurrent admission control decisions in multiservice networks, putting forward solutions to mitigate the negative impact that distributed admission of flows might have on the service level guarantees provided to network customers. Keeping in mind that simplicity is a key factor for deployable solutions, we suggest and discuss the use of (i) a service-dependent concurrency index; (ii) a tokenbased system and (iii) a rate-based credit system, as alternative or complementary proposals to minimize or solve QoS degradation resulting from AC false acceptance.

Abstract—The first experience of quality by multimedia applications’ users takes place during the setup phase of a new connection. If the setup phase is not accepted or “slowly accepted”, the confidence of the user decreases. The user becomes more sensitive when he/she pays the connections with assured quality of service (QoS). In this case, the process of call request should be also accomplished with QoS guarantees. This paper presents the signaling sub-system implemented within the EuQoS system. The EuQoS signaling process follows main assumptions of next generation networks (NGN) architecture and performs tasks related with codec agreement between multimedia end users, admission control and resource reservation functions. In this paper, we present analytical, simulation and experimental results showing the impact of signaling system performance on quality of experience (QoE) for the potential users of multi-layer EuQoS system. In particular, the presented approach aims at ensuring user QoE of the connection setup phase by ensuring QoS for transferring signaling messages by the network. Keywords—call setup delay, class of service, heterogeneous networks, next generation networks, quality of experience, quality of service, signaling system. 1.