Quality of service on the internet: evaluation of RSVP based solutions.

The Internet represents nowadays the most important communication medium used by billions of persons around the globe. One of the problems associated with the evolution of the Internet is that since the beginning it was conceived as a best-effort service delivery model. However, this model was transformed over time. The alteration of the Internet best-effort service delivery model is a direct consequence of the introduction of real-time services that are sensitive to Quality of Service (QoS) parameters. This dissertation starts by analyzing the current service delivery models that exist in the Internet (Chapter 1), covering also the motivation that triggered the introduction of each model separately. Subsequently, a special focus is given to the Resource Reservation Protocol (RSVP). RSVP represents one of the most important protocols used for resource reservation in the Internet. A thorough analysis of the evolution of RSVP is presented in Chapter 2. Throughout this thesis, simulation will be used to analyze, evaluate, and test different propositions that relate in one way or another with RSVP. OPNET Modeler represents the network simulation tool that was used in this context. Some details about how OPNET functions, what are the main characteristics of this simulation tool, how protocols can be altered or implemented, and how RSVP is implemented in OPNET Modeler are illustrated in Chapter 4. Chapter 5 concentrates on evaluating the impact of employing admission control by using RSVP as a capacity admission strategy in one of the service delivery models (the Differentiated Service mechanism). In this context, a new service delivery model for the Internet is proposed: the two-stage service differentiation model (tsSDM). One of the main issues associated with RSVP is the scalability problem of the protocol. Running RSVP requires resources, in terms of processing power and memory space. For each established reservation of a particular session RSVP messages have to be generated, transmitted, and processed within a certain period. In Chapters 6 and 7, this scalability problem of RSVP comes into focus. In Chapter 6, the main requirements and the most important technical aspects that need to be taken into consideration in order to implement the Bundle extension and respectively the Summary Refresh extension in OPNET Modeler are presented. Moreover, a quantifiable measure of the scalability of RSVP and of the two associated extensions is offered, based on the execution overhead introduced by the protocol. Chapter 7 continues the work on the scalability of RSVP by evaluating the performance of the RSVP Aggregation extension. Proposed as an alteration of the original protocol design, the Aggregation extension was introduced in order to address the scalability problem of the protocol. Practical considerations and key design choices made during the implementation process are illustrated in this chapter. Furthermore, the scalability and the QoS that can be obtained by using this alteration of RSVP are analyzed.nrpages: 303status: publishe

A survey on the evolution of RSVP

The Resource Reservation Protocol (RSVP) represents one of the most important protocols used for resource reservation in the Internet. Developed initially by the Internet Engineering Task Force (IETF) to be used within the Integrated Services (IntServ) mechanism, this protocol undergoes over time several alterations. These alterations come either to respond to some applicability and functionality problems, or to extend the use of RSVP and to make it compatible with other mechanisms like Differentiated Services (DiffServ) or Multiprotocol Label Switching (MPLS). This work presents a survey on the evolution of RSVP illustrating the different alterations introduced over time for this protocol and explaining how each adaptation affects RSVP in functional terms. © 1998-2012 IEEE.status: publishe

Practical considerations for enabling a srTCM behavior in Opnet modeler

Different Quality of Service (QoS) mechanisms have been proposed over time. Differentiated Services (DiffServ) represents one of the main QoS mechanisms developed, and is based on a strategy of traffic differentiation. Introduced in order to be used within DiffServ, the single rate Three Color Marker (srTCM) represents a policer which meters the IP packet stream and marks the traffic with different drop probabilities. This paper presents the technical aspects of implementing the srTCM in one of the most important network simulation tools on the market, OPNET Modeller. Practical considerations and a test case of the proposed implementation are presented.status: publishe

Implementing RSVP-based capacity admission in OPNET modeler

OPNET Modeler represents nowadays one of the most important simulation tools used by the research community in the area of Quality of Service (QoS). Because of the complexity and of the multitude of configurations that are possible in a network domain or in the Internet, a number of specific implementations of QoS mechanisms are not yet available in simulation tools. This paper presents a new type of queue configuration mechanism that enables the dynamic creation of Resource Reservation Protocol (RSVP) queues, while maintaining the properties of the Differentiated Service (DiffServ) queue scheduling discipline for a specific interface. Practical considerations for extending the queue management facilities and supported QoS abilities of OPNET Modeler are illustrated.status: publishe

RSVP bundle extension in OPNET modeler: implementation and evaluation

The Resource Reservation Protocol (RSVP) represents one of the most important protocols in the field of Quality of Service (QoS). Over time different extensions of RSVP have been proposed by the Internet Engineering Task Force (IETF) in order to mitigate the scalability issue of the protocol. The RSVP Bundle extension is such a scalability extension. Most important network simulation tools do not have an implementation of the RSVP Bundle extension, thus making it hard to analyze the scalability of RSVP and the behavior of the protocol in complex scenarios that might use the aforementioned extension. This paper presents the implementation and evaluation of the RSVP Bundle Extension in OPNET Modeler. Technical aspects that can help researchers implement or modify different RSVP extensions in OPNET Modeler are presented.status: publishe

Performance evaluation of RSVP using OPNET modeler

RSVP represents one of the most discussed network protocols in the last decade. Although there are a large number of papers that refer to the scalability problem of the protocol, only a very limited subset of those analyze the performance of RSVP. Up to this point no real evaluation exists on the efficiency and applicability of the scalability extensions proposed for RSVP. This paper presents a simulation study of RSVP and its scalability extensions in OPNET Modeler. The results obtained are put in context of the previous work done on the scalability of RSVP. It is found that the Summary Refresh extension considerably improves the performance of the protocol both in terms of message processing and message generation. An important finding of the present paper is that the scalability of RSVP is not directly linked to the specifications of the protocol and its extensions as such, but rather to the design choices of the actual implementation under evaluation.publisher: Elsevier articletitle: Performance evaluation of RSVP using OPNET Modeler journaltitle: Simulation Modelling Practice and Theory articlelink: http://dx.doi.org/10.1016/j.simpat.2014.08.005 content_type: article copyright: Copyright © 2014 Elsevier B.V. All rights reserved.status: publishe

Implementation of the srTCM in OPNET modeler

The single rate Three Color Marker (srTCM) was proposed by the Internet Engineering Task Force (IETF) to be used within the Differentiated Service (DiffServ) mechanism for Quality of Service (QoS). This paper illustrates the technical aspects of implementing the srTCM in OPNET. In order to implement this policer with a minimum effort we use the already existing code of the CAR policer. Practical considerations that will help researchers implement other policer tools in this simulation environment are presented. Also a test case is constructed in order to analyze the functionality of the proposed implementation.status: publishe