Restoration in multi-domain GMPLS-based networks

In this paper, we evaluate the efficiency of using restoration mechanisms in a dynamic multi-domain GMPLS network. Major challenges and solutions are introduced and two well-known restoration schemes (End-to-End and Local-to-End) are evaluated. Additionally, new restoration mechanisms are introduced: one based on the position of a failed link, called Location-Based, and another based on minimizing the additional resources consumed during restoration, called Shortest-New. A complete set of simulations in different network scenarios show where each mechanism is more efficient in terms, such as, resource overbuild or recovery delayPart of this work was supported by the Government of Catalonia (DURSI SGR-1202), and by the Spanish Science and Innovation Ministry (TRION TEC2009-10724

ANÁLISIS DE LA INCIDENCIA DE FALLAS MÚLTIPLES EN REDES MPLS

RESUMENDentro del contexto actual de las redes de telecomunicaciones, las tendencias apuntan al uso de servicios y aplicaciones con altas exigencias de recursos de red, características de QoS y disponibilidad, lo cual ha llevado a los operadores a adoptar MPLS como tecnología de soporte en el núcleo de sus redes, gracias a las ventajas que ofrecen en la velocidad de conmutación y enrutamiento de tráfico. En estas condiciones, la ocurrencia de eventos de falla en la red puede degradar de manera considerable su desempeño y afectar severamente las características de los servicios soportados por la misma, llevando en algunos casos críticos a la pérdida total de información. Este artículo presenta un análisis del impacto que tiene la ocurrencia de eventos de falla múltiple sobre una red MPLS, evaluando para ello algunos parámetros de desempeño (pérdida de paquetes, desorden, retardo, jitter, tiempo de restablecimiento) sobre los tráficos transportados. Se plantea un escenario de simulación sobre el cual se programan fallas usando el simulador NS-2 (Network Simulator) y se evalúa el impacto ocasionado por estos eventos tanto cuando no se aplica ninguna estrategia de recuperación como cuando se aplican los métodos de protección (Global, Local e Inverso) con el objeto de verificar si es posible recuperar los tráficos comprometidos bajo tales condiciones y mantener las características de QoS requeridos por los servicios soportados por ella.PALABRAS CLAVES: MPLS, Falla múltiple, Recuperación, Parámetros de desempeño. ANALYTICAL SUMMARYNowadays, most network operators have been forced to adopt MPLS as the support technology for the core in their networks, as a result of the trends in the usage of services and applications which demand a lot of network resources, special QoS properties and high availability. MPLS makes it possible thanks to the high switching and routing speeds that this technology offers. In these scenarios, however, the occurrence of failure events in the network could critically decrease its performance, and as a consequence affect the services which are carried by the network, leading in the worst case scenarios to the complete loss of information. This paper presents an analysis on the impact associated to the occurrence of failure events on MPLS networks. Performance parameters are evaluated such as packet loss, packet disordering, delays, jitter and restoration time. A simulation scenario is proposed where multiple failure events are simulated by using Network Simulator (NS-2), and the impact induced by these events is evaluated when no recovery strategy is applied and also by using protection methods on the proposed scenario as an alternative to recover the affected traffics, so QoS properties and the original conditions for the services carried by the network can be kept unaltered.  KEYWORDS: MPLS, Multiple Failures, Recovery, Performance parameters.

ANÁLISIS DE LA INCIDENCIA DE FALLAS MÚLTIPLES EN REDES MPLS

RESUMENDentro del contexto actual de las redes de telecomunicaciones, las tendencias apuntan al uso de servicios y aplicaciones con altas exigencias de recursos de red, características de QoS y disponibilidad, lo cual ha llevado a los operadores a adoptar MPLS como tecnología de soporte en el núcleo de sus redes, gracias a las ventajas que ofrecen en la velocidad de conmutación y enrutamiento de tráfico. En estas condiciones, la ocurrencia de eventos de falla en la red puede degradar de manera considerable su desempeño y afectar severamente las características de los servicios soportados por la misma, llevando en algunos casos críticos a la pérdida total de información. Este artículo presenta un análisis del impacto que tiene la ocurrencia de eventos de falla múltiple sobre una red MPLS, evaluando para ello algunos parámetros de desempeño (pérdida de paquetes, desorden, retardo, jitter, tiempo de restablecimiento) sobre los tráficos transportados. Se plantea un escenario de simulación sobre el cual se programan fallas usando el simulador NS-2 (Network Simulator) y se evalúa el impacto ocasionado por estos eventos tanto cuando no se aplica ninguna estrategia de recuperación como cuando se aplican los métodos de protección (Global, Local e Inverso) con el objeto de verificar si es posible recuperar los tráficos comprometidos bajo tales condiciones y mantener las características de QoS requeridos por los servicios soportados por ella.PALABRAS CLAVES: MPLS, Falla múltiple, Recuperación, Parámetros de desempeño. ANALYTICAL SUMMARYNowadays, most network operators have been forced to adopt MPLS as the support technology for the core in their networks, as a result of the trends in the usage of services and applications which demand a lot of network resources, special QoS properties and high availability. MPLS makes it possible thanks to the high switching and routing speeds that this technology offers. In these scenarios, however, the occurrence of failure events in the network could critically decrease its performance, and as a consequence affect the services which are carried by the network, leading in the worst case scenarios to the complete loss of information. This paper presents an analysis on the impact associated to the occurrence of failure events on MPLS networks. Performance parameters are evaluated such as packet loss, packet disordering, delays, jitter and restoration time. A simulation scenario is proposed where multiple failure events are simulated by using Network Simulator (NS-2), and the impact induced by these events is evaluated when no recovery strategy is applied and also by using protection methods on the proposed scenario as an alternative to recover the affected traffics, so QoS properties and the original conditions for the services carried by the network can be kept unaltered.  KEYWORDS: MPLS, Multiple Failures, Recovery, Performance parameters.

An ISP and end-user cooperative intradomain routing algorithm

The continuous growth in volume of Internet traffic, including VoIP, IPTV and user-generated content, requires improved routing mechanisms that satisfy the requirements of both the Internet Service Providers (ISPs) that manage the network and the end-users that are the sources and sinks of data. The objectives of these two players are different, since ISPs are typically interested in ensuring optimised network utilisation and high throughput whereas end-users might require a low-delay or a high-bandwidth path. In this paper, we present our UAESR (Utilisation-Aware Edge Selected Routing) algorithm, which aims to satisfy both players' demands concurrently by selecting paths that are a good compromise between the two players' objectives. We demonstrate by simulation that this algorithm allows both actors achieve their goals. The results support our argument that our cooperative approach achieves effective network resource engineering at the same time as offering routing flexibility and good quality of service to end-users

Intra-Domain Delay-Based Quality of Service Using Differentiated Routing

Differentiated routing is an approach to providing service differentiation in networks, a field that is currently receiving significant research attention. In this report we present an algorithm, namely Intra-Domain Differentiated Routing (IDDR), which supports qualitative delay differentiation in IP networks. We review existing differentiated routing approaches and then introduce IDDR and present initial results. We demonstrate that using IDDR we can achieve qualitative delay differentiation for two classes of flows