A Survey on the Path Computation Element (PCE) Architecture

Quality of Service-enabled applications and services rely on Traffic Engineering-based (TE) Label Switched Paths (LSP) established in core networks and controlled by the GMPLS control plane. Path computation process is crucial to achieve the desired TE objective. Its actual effectiveness depends on a number of factors. Mechanisms utilized to update topology and TE information, as well as the latency between path computation and resource reservation, which is typically distributed, may affect path computation efficiency. Moreover, TE visibility is limited in many network scenarios, such as multi-layer, multi-domain and multi-carrier networks, and it may negatively impact resource utilization. The Internet Engineering Task Force (IETF) has promoted the Path Computation Element (PCE) architecture, proposing a dedicated network entity devoted to path computation process. The PCE represents a flexible instrument to overcome visibility and distributed provisioning inefficiencies. Communications between path computation clients (PCC) and PCEs, realized through the PCE Protocol (PCEP), also enable inter-PCE communications offering an attractive way to perform TE-based path computation among cooperating PCEs in multi-layer/domain scenarios, while preserving scalability and confidentiality. This survey presents the state-of-the-art on the PCE architecture for GMPLS-controlled networks carried out by research and standardization community. In this work, packet (i.e., MPLS-TE and MPLS-TP) and wavelength/spectrum (i.e., WSON and SSON) switching capabilities are the considered technological platforms, in which the PCE is shown to achieve a number of evident benefits

Gerência em redes GMPLS: vantagens e desvantagens de sua implementação

With the advent of new services based on IP, the need for bandwidth grows rapidly at the Internet backbones. The need of carry even more traffic and keep costs as lower as possible, points to new solutions with requirements of escalability, flexibility, low cost and easy of operation. Today, to carry this traffic in an efficient way and with low cost has been a great challenge, specially with the current infrastructure based in four layers. Some proposals have appeared to address these issues. Among them the GMPLS is distinguished. The GMPLS and its extensions to the routing and signaling comes to setting itself as an excellent solution to address the current problems found in the management and provisioning of the great ISPs.Com o advento de novos serviços baseadas em IP, a demanda por largura de banda nos backbones de internet cresce em ritmo acelerado. A necessidade de carregar cada vez mais tráfego mantendo os custos baixos aponta para que novas soluções sejam desenvolvidas e que possuam os requisitos de escalabilidade, flexibilidade, baixo custo e facilidade de operação. Atualmente, carregar este tráfego de maneira eficiente e com baixo custo tem sido um grande desafio, principalmente com a atual infra-estrutura baseadas em quatro camadas. Algumas propostas têm surgido para tentar resolver estes problemas. Dentre elas destaca-se o GMPLS. O GMPLS com suas extensões aplicadas a roteamento e sinalização vem se firmando como uma excelente solução para endereçar os atuais problemas encontrados na gerência e aprovisionamento dos grandes ISPs

GMPLS Conmutación de etiquetas multiprotocolo generalizado

El imparable crecimiento de servicios de banda ancha que las redes de telecomunicación ha de soportar, está llevando a una evolución en el diseño de dichas redes que permita de una manera eficiente la conmutación y enrutamiento de los grandes volúmenes de datos que han de transportarse. GMPLS puede verse, por tanto, como un integrador de las arquitecturas ópticas y de datos, y como tal, su desarrollo necesita de mejoras de la señalización y de los protocolos de encaminamiento IP actualmente existentes para extenderlos al entorno óptico. Los trabajos más recientes en este sentido intentan adaptar el plano de control MPLS, y especialmente sus protocolos de señalización y encaminamiento (CR-LDP y RSVP-TE “Constraint Based Routing Label Distribution Protocol” y “Resource Reservation Protocol-Traffic Engeneering” respectivamente), de manera que no solo sea utilizado por los routers y conmutadores ATM, sino también por los cross-conectores ópticos (OXCs). Así mismo, GMPLS ha marcado el desarrollo de nuevos protocolos como el LMP (“Link Management Protocol”). Pero más allá de la solución tecnológica, GMPLS también resuelve el factor económico al posibilitar una arquitectura de red más optimizada para transportar grandes volúmenes de tráfico que las actuales