Path computation element: Difference between revisions

Revision as of 14:37, 31 March 2023

Revision as of 17:49, 11 June 2023

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==Description==

Routing can be subject to a set of constraints, such as [[quality of service]] (QoS), policy, or price. Constraint-based path computation is a strategic component of traffic engineering in [[MPLS]], [[GMPLS]] and [[Segment Routing]] networks. It is used to determine the path through the network that traffic should follow, and provides the route for each [[Labellabel-switched Switched Pathpath]] (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 typically available at a network element, yet may still need to be more dynamic than can be provided by a management system.

Thus, a PCE is an entity capable of computing paths for a single or set of services. A PCE might be a [[Computer network|network]] node, network management station, or dedicated computational platform that is resource-aware and has the ability to consider multiple constraints for sophisticated path computation. PCE applications compute 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''.<ref name=pce>IETF's Working Group, [http://www.ietf.org/html.charters/pce-charter.html "Path Computation Element (pce)"] {{webarchive|url=https://web.archive.org/web/20090710130634/http://www.ietf.org/html.charters/pce-charter.html |date=2009-07-10 }}</ref>

PCE represents a vision of networks that separates route computations from the signaling of end-to-end connections and from actual [[packet forwarding]]. There is a basic tutorial on PCE as presented at ISOCORE's MPLS2008 conference<ref name=tutorial>Basic PCE tutorial [http://www.olddog.co.uk/Farrel_PCE_Tutorial.pdf "PCE Tutorial"]</ref> and a tutorial on advanced PCE as presented at ISOCORE's SDN/MPLS 2014 conference.<ref name=AdvTutorial>Advanced PCE tutorial [http://www.olddog.co.uk/AdvancedPCE.pdf "Advanced PCE Tutorial"]</ref>