Path computation element
 | This article provides insufficient context for those unfamiliar with the subject. (July 2008) |
Routing is the process of finding a suitable route for conveying data between a source and one or a set of destination. Routing can be subject to a set of constraints, like QoS, policy, or price. Constraint-based path computation is a strategic component of traffic engineering in MPLS and GMPLS networks. It is used to determine the path through the network that traffic should follow, and provides the route for each Label Switched Path (LSP) that is set up.
Path computation has previously been performed either in a management system or at the head-end of each LSP. But path computation in large, multi-domain networks may be very complex and may require more computational power and network information than is usually available at a network element, yet may still need to be more dynamic than can be provided by a management system.
A Path Computation Element (PCE) is defined by the Internet Engineering Task Force (IETF) in RFC 4655 [1], as
An entity (component, application, or network node) that is capable of computing a network path or route based on a network graph and applying computational constraints
Thus, a PCE is an entity capable of computing complex paths for a single or set of services. A PCE might be a network node, network management station, or dedicated computational platform which is aware of the network resources and has the ability to consider multiple constraints for sophisticated path computation. PCE applications include computing Label Switched Paths for MPLS and GMPLS Traffic Engineering. The various components of the PCE architecture are in the process of being standardized by the IETF's PCE Working Group[2].
PCE represents a modern vision of networks where route computations should more or less be separated from actual packet forwarding.
PCE extensions
There are several PCE extensions to achieve different goals. For example:
References
- ^ RFC 4655, "A Path Computation Element (PCE)-Based Architecture"
- ^ IETF's Working Group, "Path Computation Element (pce)"
- ^ M. Domínguez-Dorado, José-Luis González-Sánchez, J. Domingo-Pascual. Libro de actas de las VII Jornadas de Ingeniería Telemática (JITEL'08). Págs. 80-86. ISBN 978-84-612-5474-3. Alcalá de Henares (ESPAÑA), Septiembre de 2008. "Descubrimiento de PCE inter-AS: una aportación a la computación de LSP en sistemas multidominio" (PDF).
{{cite web}}: CS1 maint: multiple names: authors list (link) CS1 maint: numeric names: authors list (link) - ^ M. Domínguez-Dorado, José-Luis González-Sánchez, J. Domingo-Pascual. Proceedings of the 13th International Telecommunications Network Strategy and Planning Symposium (NETWORKS'08). pp. 1-7. IEEE catalog number CFP08568-USB. ISBN 978-963-8111-68-5. DOI 10.1109/NETWKS.2008.4763712. Budapest (HUNGARY), October, 2008. "PILEP: a contribution to PCE-based interdomain path computation" (PDF).
{{cite web}}: CS1 maint: multiple names: authors list (link) CS1 maint: numeric names: authors list (link) - ^ M. Domínguez-Dorado, José-Luis González-Sánchez, J. Domingo-Pascual, J. Carmona-Murillo. Proceedings of the V Iberoamerican Conference on Telematics (CITA'09). pp. 14-21. ISBN 978-84-613-2679-2. Gijón (SPAIN), May, 2009. "RI-CUBE: Dotando al PCE de información abstracta de ingeniería de tráfico interdominio" (PDF).
{{cite web}}: CS1 maint: multiple names: authors list (link) CS1 maint: numeric names: authors list (link)